ZBrush to Lightwave

From ZBrush Info

by Steve Warner

Introduction

Can I be perfectly honest with you? I hate reading software manuals. The first thing I do when I open a manual is look at how many pages there are. If there are more than a dozen pages, I usually sigh and think, “Am I really going to have to read all these pages?”Then I quickly flip through the document to see how many pictures there are. I love when there are a lot of pictures. I usually try to get by with just looking at the pictures and not reading the text. However, most of the time I’m not able to do that and I eventually break down and am forced to read the whole document.

Go ahead and look at the page count for this guide. Seriously. I won’t be offended.

Woah! That’s a lot of pages. But don’t panic! You don’t have to read every bit of text to learn how to go from LightWave to ZBrush and back again. Seriously. In fact, if all you want to do is look at the pictures in the Quickstart Guide and read their captions (which is what I’d want to do) you’ll get along just fine.

But for those who do take the time to read through the entire document, you’ll find lots of extra tips and tricks that will make your experience working with each program more enjoyable. So trust me when I say you’ve got nothing to worry about. This is going to be a piece of cake.

How this guide is structured

If you’re new to ZBrush, you can simply follow the Quickstart and be off and running in no time.(Even if you’ve been using ZBrush for awhile, I suggest reading through the Quickstart as there are some really useful tips in there).

For more experienced users, the sections following the Quickstart guide will provide you with additional details that will help you be productive with this great tool.

Also, while the Quickstart section assumes you’re new to the software, that’s not entirely true for the remaining sections of this guide. I’ve attempted to make things easy to follow, even for new users. But in order to understand some ofthe advanced techniques, you’ll need at least a basic understanding of how ZBrush and LightWave work. So make sure you are familiar with the fundamentals outlined in the Quickstart section before moving on to the more chapters that follow.

Necessary Tools and Plug-Ins

LightWave 9.0 has built-in support for ZBrush displacements and normal maps. However LightWave 8.5 (and earlier) require the use of 3rdparty plug-ins. I’ll be really honest here. The ZBrush support in LightWave 9.0 is outstanding. If you don’t have LightWave 9.0 and plan on doing a lot of ZBrush work, I’d highly recommend upgrading. Not only will your models look great but they’ll render in a fraction of the time. For me, the ZBrush support alone was worth the upgrade price.

LightWave versions prior to 9.0 come with several tools for working with displacements but none of them can handle the type of displacement maps generated by ZBrush. Therefore, if you’re using LightWave 8.5 or earlier, you’ll need to download a few 3rdparty plug-ins to get the job done. I highly recommend picking each of these up. Then email the plug-in authors and tell them “Thanks!” for making it all possible.

• Lynx Normal Displacement Plug-in: This is the key to using ZBrush’s displacement maps in LightWave 8.5 and below.
• Lynx 16-bit TIFF loader: This allows you to use higher-quality displacement maps in LightWave 8.5 and below.
• ZWave: This allows you to transfer UV maps from your exported ZBrush object back into LightWave.
• TB’s Normal Map Shader: This allows you to use ZBrush’s normal maps in LightWave 8.5 and below.

Macintosh Notes

Mac users, I’ve got good news and bad news. The good news is that ZBrush works wonderfully with LightWave 9.0 on the Mac. The bad news is that it doesn’t work well with versions of LightWave prior to 9.0.

LightWave 8.5 lacks direct support for ZBrush’s various maps. That means you are forced to rely on plug-ins to get the job done. Unfortunately, not all of these are available on the Mac. Namely, the 16-bit Tiff Loader and TB’s Normal Map Shader. Without the 16-bit loader, you’ll have to use an 8-bit file, two 8-bit files (produced using MD2) or a 16-bit workaround. Without TBs Normal Map shader, your only option for using Normal Maps is to purchase a commercial plug-in like Evasion3D’s Microwave.

Barring these discrepancies, the LightWave to ZBrush pipeline is the same on the Mac as it is on the PC.

. QuickstartThere and Back Again

The following section breaks down the process of working between ZBrush and LightWave into simple, easy-to-follow steps. It is designed to get you up and running quickly and to give you the information you’ll need to establish a solid workflow. If you are new to the LightWave/ZBrush pipeline, I’d recommend that you to read through this entire section first. Then try it out on your own.

When you’re comfortable with the techniques described here, you can move on to the remaining sections of this guide. There you’ll learn about workflow variations as well as tips and tricks to make your experience with ZBrush more productive.

Let’s begin!

Load your object into Modeler

We need to make sure our object meets a few minimum requirements before we send it to ZBrush.

First, make sure that the object is made up of entirely quads or triangles. Preferably quads. If you have triangles in your object, try to hide them in less visible parts of the model.

Second, if you’re going to use LightWave’s UVs, make sure that you use one UV for the entire object and that it doesn’t have any overlapping UV geometry.

Lastly, if you’re using a LightWave generated UV, make sure that it’s applied to one of the texture channels for the surface of your object (such as the color channel). This will ensure that the UV map gets exported with the object.

If you’re not comfortable creating or editing UV maps, no worries! ZBrush can create a high-quality UV that minimizes UV distortion with the click of a button. We’ll see how easy this is in just a bit.

Once you’ve ensured that your model meets the minimum requirements, go to the File drop-down menu and from the Export menu, select Export OBJ. ZBrush uses the common . OBJ file format for importing and exporting geometry from other programs. Save your .obj to your hard drive and than save your LightWave object. We’ll return to it later.

Open ZBrush and load your object

Click on the Tools menu. Then click the orange icon that looks like circle with an arrow pointing out of it. This will dock the Tool menu on the left side of the screen.

Now click the Import button in the Tool menu. This will open up a file browser. Locate the object you just saved from LightWave and double click it to bring it into ZBrush.

Objects in ZBrush are known as Tools. You should see a tiny icon with a picture of your object in the Tool palette. Hovering over this icon will give you details about your object. This information is continually updated as you work within ZBrush to keep a running polygon count of your model.

Draw your object onto the canvas

Click and drag in the document window to place a copy of your object onto the ZBrush canvas. If you created your model in LightWave so that it faced theZ axis (as most people do), your object will come into ZBrush facing backwards. We’ll correct this in just a minute.

Click on the Edit button at the top of the interface (or use the Keyboard Shortcut “t”) to make the object editable.

Set the position and rotation of your object

Click and drag any blank portion of the canvas to rotate your object so that it’s facing forward. When it’s close, hold down the Shift key to snap the rotation.

If you need to move or resize your object, you can do so with the buttons on the right of the interface or by using keyboard shortcuts.

Double clicking on the Move icon will restore your object’s size and position. Go ahead and double click the Move icon now.

Create a UV map

If you didn’t import an object with an existing UV map (i.e. one you created in LightWave), now would be a good time to create one.

Click the Texture menu in the Tool palette to drop down it’s options. Then click the GUVTiles button. This applies ZBrush’s advanced Group UV to your model. Group UV Tiles produces a nearly distortion free UV map with the click of a button. If you’re like me and you hate the tedious nature of hand-tweaking a UV map, you’ll find ZBrush’s Group UV Tiles (and it’s cousin, AUVTiles) a godsend.

That’s it for creating a UV map. Cool, huh?

Subdivide your object

Now that our model is on the canvas and we have a UV for it, it’s time to subdivide our object.

From the Tool menu, click on the Display Properties submenu to open its options. Increase the DSmooth slider from 0 to 1. This is like turning on Smoothing for a surface in LightWave. Now open the Geometry submenu. Click on the Suv option to make sure your UVs are smoothed when you subdivide your object. Then click on the Divide button a couple of times.

Each time you subdivide, you’re adding more polygons to your object. The more polygons, the more details you can paint. The trick here is to only use as much geometry as is necessary to alter the shape of your object. Here, I’ve increased my subdivision level (SDiv Level) to 5.

Store a morph target

ZBrush is a multi-resolution editing tool. You can increase and decrease the number of polygons in your object at any time, making broad changes at low subdivision levels and detailed changes at higher subdivision levels. These changes ripple up and down the various subdivision levels, so simple changes made at subdivision level 1 (when the model has fewer points) will cause broader changes to the model at subdivision levels 5, 6 or 7. And detailed changes at levels 5, 6 or 7 (when the model has more points) will cause only minor changes at subdivision level 1.

The morph target is your ZBrush safety net. It offers several benefits. It allows you to “erase” specific deformations by using the Morph Edit Brush found in the Transform menu. It allows you to update your object’s UV map at any point without losing any work you’ve done. And it can be used to return your model to its original shape when generating displacement and normal maps.

Begin sculpting your object

The Draw Pointer tool is the default brush used for painting deformations onto imported 3D objects. It has two modes:ZAdd and ZSub. ZAdd makes the area under your cursor buldge outward. ZSub makes the area under your cursor recede inward. The strength of the brush is controlled through the Z Intensity slider.

The cursor in ZBrush looks like two red circles. The outer circle indicates the overall size of your brush. It can be controlled using the Draw Size slider. The inner circle represents the focus area of the brush, where the maximum amount of Z Intensity you’ve set will be applied. The intensity of your brush will fall off gradually from the inner circle to the outer circle. This falloff can be adjusted using the Focal Shift controls.

When you place your cursor over any portion of your object, you’ll also get a small red dot close to the center of those circles. This small dot indicates the current vertex that your cursor is over and can be helpful in identifying exactly what part of your object you will be affecting.

At times you might find it useful to see the underlying wireframe structure of your mesh. To turn on wireframe viewing, click the Frame button at the upper left corner of the interface. If you don’t see the Frame button, make sure you’re in Quick 3D Edit mode by clicking the Quick button in the upper left corner of the interface.

Sculpting details onto a symmetrical object can be made much easier by using ZBrush’s advanced symmetry mode.

Click on the Transform menu at the top of the interface and click on the >X< icon to activate symmetry. The keyboard shortcut for this is simply “x”, which makes it easy to turn symmetry on and off as you paint. Unlike LightWave’s symmetry mode that requires your points to be perfectly symmetrical, ZBrush can paint symmetrically on an object, even if the points don’t match across the X axis.

Create a texture and prepare it for use as a bump map

Fine detail (such as wrinkles, pores, etc.) are best handled by a bump map. ZBrush allows you to paint a bump map directly on your object and see the results as they’ll appear in LightWave (which is so cool!).

Click on the SysPalette button to open the System Palette. Choose the medium grey whose Red, Green and Blue values are all 128. Then click OK.

Now click the Texture menu at the top of the interface to drop down its options.(You can click the orange widget to dock this to the left side of the interface if you’d like.)Click in the Width and Height fields and enter 2048 for each. Then click New. This will create a new texture with a resolution of 2048x2048 and will fill it with the medium grey color we selected earlier.

This is where the magic begins. To see the effects of the bump map being applied to your object, you will need to use a special Material. Materials in ZBrush are similar to Surfaces in LightWave. However Materials take advantage of a number of advanced OpenGL routines which allow you to see a variety of effects without having to render. One of these is the effect of a bump map.

Click on the material icon (or go to the Material menu at the top of the interface) and click the Load button. Navigate to your ZBrush install directory.(Typically this will be in the C:\Program Files\Pixologic\ZBrush2 folder on the PC). Locate the ZMaterials folder and load the BumpViewMaterial.zmt file. Once the Bump View Material is active, you’ll notice that your object is both brighter and has more specular highlights.

You can paint on the bump map using the standard brush you use for deformations, but I’m going to show you a better way.

Use Projection Master to paint your bump map

Projection Master lets you paint intricate details onto your model using a variety of brushes and alpha masks. Click the Projection Master button at the upper left corner of the interface. This will open the Projection Master options window.

You can paint Colors, Materials or Deformations with Projection Master. Since we’re only painting a bump map, we just want the Colors (or in this case, shades of grey) option checked. Make sure this is the case. Then click the Drop Now button.

Click the SysPalette button and choose pure black. Then make sure that only the RGB button at the top of the interface is highlighted. If Zadd or Zsub is selected, make sure to turn them off. This will ensure that we’re only painting pure colors onto our object.

Draw a few strokes over your object and notice how it appears to cut into the surface. You’re now painting a bump map directly on the surface of your object in real-time! No geometry is actually being modified. This is all being done with the bump map.

Projection Master defaults to using a tool called the Single Layer Brush with a soft round Alpha and a dotted Stroke. Try out the different brushes, alphas and strokes to get a feel for how they affect your object.

Using a black color will cut brush strokes into your object. Switching to a white color will cause the brush strokes rise up from the surface. You can vary the intensity of your brush strokes by changing the RGB Intensity slider. If you want to restore the surface (for example, to cover up any mistakes), simply switch back to a medium grey, set the RGB Intensity to 100 and paint over the surface.

When your model is dropped to the canvas, it can no longer be rotated. To rotate your object and continue painting on other parts of its surface, you’ll need to exit out of Projection Master. Entering and exiting Projection Master is something you’ll do often as you paint various types of maps. For this reason, it’s helpful to remember its keyboard shortcut, which is ëG’.

Click on the Projection Master button again to bring up its options. Then click on the Pickup Now button to return to ZBrush’s standard object edit mode.

Save your bump map

When you’re happy with the work you’ve done in ZBrush, you need to save out the various maps for use in LightWave. We’ll begin by saving out our bump map.

Open the Texture menu at the top of the interface (or from the side if you docked it earlier). Make sure the bump map is currently selected. Then press the Flip V button to flip the texture vertically. I know this seems like a strange thing to do. But ZBrush’s UV coordinates are the inverse of LightWave’s. If you don’t flip the texture, it won’t like up properly with the UV once you’re back in LightWave.

Click the Export button in the Texture menu and save the bump map as a standard Photoshop PSD file.

Create a displacement map

Displacement maps allow you to deform the shape of your object in LightWave in order to replicate the changes you made in ZBrush.

Begin by lowering your subdivision level back to one.

Click on the Displacement submenu from the Tools palette to open its options. Click in the DPRes field and enter 2048 to set the size of the displacement map to 2048x2048.

Also, make sure that you turn on Smooth UV and Adaptive mode. Then click the Create DispMap button to generate a displacement map. Depending on the speed of your computer and the complexity of the map, this can take a few seconds or upwards of several minutes.

When ZBrush finishes calculating your displacement map, it will place it into the Alpha bin as a grayscale texture. We need to flip this texture just like we did for our bump map, so click on the Alpha menu at the top of the interface. Make sure your displacement is selected as the current alpha, then click the Flip V button.

Now click the Export button to bring up the Export Image window. Select a location to save your file. Then, from the Save As Type menu, choose TIF. The TIF files saved from ZBrush’s Alpha menu use 16-bits per channel and will provide higher quality results than standard 8-bit per channel files such as BMP or PSD.

Create a Normal Map

Normal maps are like bump maps on steroids. They don’t actually alter the shape of your object (as the displacement map does), but they give the appearance of doing so. This makes them well-suited for situations that require highly detailed objects but lack the time or horsepower required to render multi-million polygon objects.

Normal maps can be used on their own or in conjunction with displacements and traditional bump maps. I find that by using them in conjunction with the other maps, I can get outstanding results while cutting down on the render time per frame.

Click on the NormalMap submenu just below the Displacement submenu in the Tools palette. Set the NMRes (Normal Map Resolution) to 2048 and turn on Adaptive and SmoothUV. The last button in the NormalMap menu is the Tangent button. If you’re using LightWave 9, make sure this button is selected. If you’re using LightWave 8.5 or earlier, make sure this is not selected.

LightWave 8.5 (and earlier) users will also need to make a slight change to the Normal Map Export preferences in order to get their maps to work properly. Open the Preferences menu at the top of the screen and click on the ImportExport options. Activate the “NormalMapFlipX” and “NormalMapFlipZ” buttons. If these options are not set, your normal map will not work properly. Keep in mind that these settings only apply to LightWave 8.5 and earlier. Users of LightWave 9 should leave these settings unchecked.

Once your options are set, click on the Create NormalMap button in the Tool menu to generate your normal map. When finished, it will become the active Texture and you’ll see it applied to your object.

The Normal Map will need to be flipped just as was done with the Bump Map and Displacement Map. To do this, open the Texture menu at the top of the interface (or from the side if you docked it earlier). The Normal Map should be the active texture. Press the Flip V button to flip it vertically. Then press the Export button and save your map in the Photoshop format.

Export your model

Since we used ZBrush to create our UV map and we also created our normal and displacement maps from the Subdivision Level 1 object, we need to export our model so that everything will work properly in LightWave.

Click on the Export submenu from the Tool menu to drop down its options. Make sure that Obj is selected and leave everything else at its default. Then click the Export button to save the object to your hard drive.

Save your ZBrush model

Before leaving ZBrush, it’s a good idea to save the current object in ZBrush’s native ZTL format.

Click on the Save As button in the Tool menu and save the object to your hard drive. If you have a texture currently loaded (such as the bump map we created earlier), ZBrush will ask you if you’d like to save the map with the file. Choose OK.

Bring your work back into LightWave

There are two ways to get your ZBrush object into LightWave. The first (and easiest) is to simply load the OBJ file, press TAB to convert the polygons into subpatches and resave the model as a standard LightWave object (. LWO). This method will work so long as your original LightWave object didn’t have any “extras” such as weight maps or endomorphs that you wanted to keep. You see, the OBJ format doesn’t recognize these so they are removed when you export your OBJ file from LightWave.

If your model does have endomorphs or weight maps, you’ll have to transfer the geometry changes and UV map from the exported ZBrush OBJ file back onto your existing LightWave model. This requires a little extra work, but it’s not hard and it’s certainly faster than recreating all your endomorphs and/or weight maps from scratch. Since the former method is so simple, let’s take a look at the latter approach.

We’ll begin by pulling the UV map from our ZBrushed OBJ file. We could do this by copying and pasting the UVs from one object to another, but LightWave has trouble with discontinuous UVs and will choke on the UVs we made in ZBrush. Fortunately, there is a brilliant little plug-in called ZWave that allows us to transfer the UVs from our ZBrushed OBJ back to our original LightWave model.

Open Modeler and load in your original LightWave objectthe one you used to export the OBJ for ZBrush.

From the Utilities/Additional menu, scroll down and select the ZWave plug-in. Click the Import File button and select the OBJ file you saved out of ZBrush. Leave the Texture Name as OBJ_UVTextureMap and leave the Replace Existing Texture option checked. Then click OK.

Bam! The UV map is now a part of your original LightWave object. Sweet, huh?

Now it’s time to copy the geometry changes. Open up the OBJ file that you exported from ZBrush. Copy the object and paste it into a blank layer in your original object.

Place your original object in the foreground and your ZBrushed object in the background. Then, from the Map tab, choose Bkg to Morph.

Leave the Endomorph name as “BkgMorph” and press OK. The ZBrushed object is now a part of our original LightWave model.

The last thing we need to do is move the points from the morph to the base state of our model. This will not only make the default appearance of our model look just like the ZBrushed object, it will also cause any existing endomorphs to be based on the ZBrushed changes.

Make sure your original object is selected (not the ZBrushed object) and that the (base) object is active. From the Map tab, run the Apply Morph tool. Select the BkgMorph from the MORF VMap drop-down and set the strength at 100%. Then press OK.

Now let’s clean things up. Make sure the M button at the bottom of the interface is highlighted so that we can choose an endomorph. Then from the pop-up menu, choose the BkgMorph. With this morph selected, choose the Clear Map command from the Map menu. Then switch back to the Base object state. This eliminates the BkgMorph. Now go to the layer that you copied the ZBrushed object onto and press Delete to remove it.

Finally, switch back to the object with your original object. Press TAB to turn on subpatches and save your object with a new name.

Place the object in Layout

Open the model you saved in the last step into Layout and create a standard three-point light setup. The three point light setup may not be the most creative light rig, but it will do a good job of helping us see the details of the model we’re working on.

Now frame the camera so that the head model fills the screen. When you’re ready, save your scene.

Apply the displacement map to your object

Over the next few steps we’ll recreate the details we sculpted in ZBrush on our LightWave object. We’ll do this by applying the displacement map (to alter the overall shape of our object), the normal map (to fill in the displacement details) and the bump map (to simulate high-frequency details). First, let’s apply the displacement map.

Click on your object to make sure it’s selected in Layout. Hit the ëp’ key to open the object properties window then click on the Deform tab. The steps for applying the displacement map differ from LightWave version 8.5 to 9.0. Let’s begin by taking a look at how to apply your map in LightWave 9.0

Adding the displacement in LightWave 9.0

Click the checkbox next to the Edit Nodes button to enable node displacement.

From the Node Displacement Order pop-up menu, choose “Before Local Displacement”.

Click on the Edit Nodes button to open the node editor. Fortunately we don’t have to construct a complicated node setup to use our ZBrush displacement map. LightWave 9 ships with a custom node tree specifically designed for use with ZBrush. We’ll simply load this node tree and make a few small changes.

From the Edit menu in the node editor, choose Import Nodes. Select the ZBrush node setup that came with LightWave 9.0.

Double-click on the Image node. From the Image pop-up menu, select “(load image)” and select the displacement map you saved out of ZBrush.

From the Mapping pop-up select UV Map. For the UV Map pop-up, select the OBJ_UVTextureMap that was saved with your OBJ file.

Close the Image node. Now we need to apply the displacement to our object. Drag the blue Result output from the Scale node and connect it to the Displacement Input.

Double-click the Multiply Node to open its properties. This node controls the amount of displacement and it defaults to 0.1. In my experience, this is a bit too low. Go ahead and increase the B value from 0.1 to 0.25. This is nothing more than a guess at a good value to start with. Close the Multiply node properties window and then close the Node Editor.

Now we need to change our Display Subpatch level and our Subdivision order. Click on the Geometry tab of the Object Properties panel and change the Subdivision Order pop-up menu from First to After Bones. Then increase your Display SubPatch level from its default of 3 to 10.

Lastly, we need to change our Subpatch Render level.

LightWave uses a different technology for working with displacement maps than ZBrush. In order to replicate the details of your ZBrush model, you need to increase the number of polygons in your LightWave object, even beyond that which you had in ZBrush. I find that I typically need between 2 to 4 times the number of polygons used by ZBrush to get the details I want in LightWave. So, for example, if my highest subdivision level in ZBrush was 5, and that yielded approximately 450,000 polygons, I’ll need anywhere from 900,000 to 1,800,000 polygons in LightWave. You increase the number of polygons available to you by changing the Render Subpatch level.

In LightWave 9, we have three options available for defining our render subpatch level. We can increase the subpatch level on a per object basis, on a per polygon basis, or we can set the number of pixels to use for each polygon in our object. Good results can typically be obtained using the Per Object mode and setting the level between 10 and 20. For true sub-pixel displacement, you can set the Render Subpatch to Pixels per Polygon and then lower the value to 0.5. That means that every polygon in the object will take up 0.5 pixels in the final render.

For now, let’s use Per Object mode with a Level of 10.

Now that we’ve set up our displacement map in LightWave 9, let’s take a look at how to do the same thing in LightWave 8.5.

Adding the displacement in LightWave versions up to 8.5

Before using your displacement map in 8.5 (or earlier), make sure that you’ve first added the Lynx Normal Displacement Plug-in and the 16-bit Tiff loader. Instructions on how to add plug-ins can be found in the LightWave manual or electronic Help file.

Click on the Add Displacement pop-up menu from the Deform tab of the Object Properties panel. Scroll down and select the NormalDisplacement plug-in to add it to your list of active displacement tools.

Double click on the Normal Displacement plug-in to open its properties window. Enter 500mm for the Displacement (which is nothing more than a good guess for a starting point) and set the Luminence Center to 50%. Everything else can be left at its default.

Click on the Texture button to open the Texture Editor. This is where we’ll add our displacement map from ZBrush.

Change the Projection to UV. Change the UVMap to the OBJ_UVTextureMap which was saved with your model out of ZBrush. From the image popup menu, load the displacement map you saved out of ZBrush. Then close the texture editor.

Go ahead and close the Normal Displacement options window. You should still have the object properties panel open. Click on the Geometry tab.

As I mentioned in the section on adding your displacement map in LightWave 9.0, LightWave uses a different technology for working with displacement maps than ZBrush. In order to replicate the details of your ZBrush model, you need to increase the number of polygons in your LightWave object, even beyond that which you had in ZBrush. I find that I typically need between 2 to 4 times the number of polygons used by ZBrush to get the details I want in LightWave. So, for example, if my highest subdivision level in ZBrush was 5, and that yielded approximately 450,000 polygons, I’ll need anywhere from 900,000 to 1,800,000 polygons in LightWave. You can increase the number of polygons available to you by changing the the Render Subpatch Levels.

Set your Render subpatch level to 10 (which is a good starting point). You can always adjust it later if you feel you need more details. Then set your Subdivision Order to After Motion.

Once the displacement map has been applied to your object (in either LightWave 8.5 or 9.0), it’s a good idea to do a quick test render. Press F9 to see how your object looks once it’s rendered.

At this point, you’ll likely need to do some tweaking to get things to look just right. Go ahead and continue tweaking the Displacement amount until you get the look you’re after. If you find that you aren’t getting the level of detail you expected from the displacement map, try increasing the subpatch level in the object properties panel, but keep in mind that we’re not through yet and more detail will appear once we’ve added our Normal Map and Bump Map.

Apply the normal map to your object

The displacement map does a great job of recreating broad changes to your object, but it requires an unruly amount of polygons to simulate the finer details. To make things a little easier, let’s add in our Normal Map.

The steps for using a normal map differ from LightWave 8.5 to 9.0. First, let’s take a look at how we’d do this in LightWave 9.

Applying a Normal Map in LightWave 9.0

Applying a Normal Map in LightWave 9 is a simple and process thanks to LightWave 9’s Node Editor. Let’s take a look at how to do this:

Open the Surface Editor. Click on the surface for your object and make sure Smoothing is turned on. Then press the check box next to the Edit Nodes button to enable node editing.

Click on the Edit Nodes button to open the Node Editor. From the Add Node drop-down menu, choose the 2D Textures/NormalMap node. Then double click on the node to open its properties.

Click on the Image drop-down in the normal map node and select (load image). Load in the Tangent Space normal map you saved out of ZBrush. From the Mapping drop down choose UV Map and then choose the OBJ_UVTextureMap as the map to use.

Close the Normal Map node. Connect the Normal output from the Normal Map node to the Normal input on the Surface. That’s it! Easy, huh? Go ahead and close the Node Editor.

Applying a Normal Map in LightWave 8.5

There are several options for using normal maps in LightWave 8.5 and earlier, but the best by far is TB’s Normal Map Shader. It works with displacement maps, bump maps and bone deformations and it’s free, making it a superb option for PC users.

Open the surface editor. Click on the surface for your object and enable Smoothing. Then click on the Shaders tab.

From the Add Shader drop-down menu, select TB_NormalMap. Then double click on the shader to open its properties. You should see a single Normal Map strength option at 100%, followed by an Envelope button and a Texture Editor button. Leave the Normal Map strength at 100% and click the “T” to open the Texture Editor.

Change the Projection to UV, choose the OBJ_UVTextureMap as the UV Map and then load in the Normal Map you saved out of ZBrush.

Now that you’ve applied your normal map (either in LightWave 8.5 or 9.0), it’s time for another test render. Turn on antialiasing and shadows. Then Press F9 to see how the Normal Map enhances the image.

You may need to adjust the strength of the Normal Map to get the look you’re after. For LightWave 9 users, you’ll need to adjust the Amplitude in the Normal Map node. Those using TB’s NormalMap shader will need to raise or lower the strength setting that appears when you double-click on the shader.

Apply the bump map to your object

The displacement map reshapes your object and the Normal Map helps fill in general details. But the bump map can really polish your object by adding “high frequency” details such as pores, small wrinkles, etc. Let’s finish things off by adding the bump map.

Applying the Bump Map in LightWave 9.0

Open the Surface Editor and select the surface for your object if it’s not already selected. Make sure that the Edit Nodes checkbox is enabled. Then open the Node Editor.

Click the Add Node button and from the 2D Textures menu, choose the Image node. Double click on the node to open its properties. Choose your Bump Map as the image, set the Mapping Type to UV and choose your UV Map.

In most cases, the default Bump Amplitude of 100% will be too low for bump maps created in ZBrush. I’ve found that a good starting point is around 1000%, with acceptable values ranging from 400% to over 1500%. If you find that you aren’t seeing the fine details (or that the bump details are simply too strong), try adjusting the Texture Amplitude. For now, set the Bump Amplitude to 1000%. Then connect the Bump output from the Image node to the Bump input on the Surface.

Close the Image node properties and close the Node Editor.

Applying the Bump Map in LightWave 8.5

Open the Surface Editor and select the surface for your object if it’s not already selected. Then click on the T button to the right of the Bump setting to open the Bump Texture Editor.

From the Projection popup menu, choose UV. From the UVMap popup, select the OBJ_UVTextureMap. From the Image popup menu, choose “Load”. Locate the Bump map PSD file you saved earlier to apply it to your object’s bump channel.

In most cases, the default Texture Amplitude of 1.0 will be too low for bump maps created in ZBrush. I’ve found that a good starting point is around 10, with acceptable values ranging from 4 to 15. If you find that you aren’t seeing the fine details (or that the bump details are simply too strong), try adjusting the Texture Amplitude.

Now that your Bump Map has been added, let’s do a sample render. Press F9 to see your results.

Finalize your render

Now that we’ve added the three primary maps, it’s time to do a little finessing to make sure that our LightWave object resembles our ZBrush sculpture as closely as possible.

Press Ctrl+F5 to open the Effects panel. From the Backdrop tab, click on the Backdrop Color. Enter 128 for the R, G and B channels. Then press OK. This will ensure that our LightWave backdrop matches the default ZBrush backdrop.

Close the Effects panel and open the Surface Editor. Click on the surface for your object. In order to match our ZBrush object, you should start with a basic surface. Remove any textures you may have applied as well as any special shaders (except for TB’s Normal Map shader).

Click on the Color swatch and give the surface an RGB of 192. Press OK to close the color picker window. Set the diffuse for your surface to 90%. Increase the Specularity and Glossiness to 20% each. Leave all other values at 0% except for the Bump map which defaults to 100%.

If you look closely, you’ll notice that the ZBrush viewport is almost orthographic. It shows little if any perspective distortion. To simulate this in LightWave, we simply move the camera back and increase the Zoom.

Move your camera far away from your object on the Z axis. Then open the Camera properties panel and increase the Zoom Factor until the object fills the screen.

Now would be a good time to do a test render. Press F9 and compare your rendered results to what you see in ZBrush.

You may find that your render has much more contrast than you see in ZBrush. To compensate for this, increase the Ambient Light Intensity. LightWave defaults this to 5%. Try increasing it to 25%. You will likely also need to adjust the Global Light Intensity to compensate. Try dropping this from its default of 100% down to 80%. In LightWave 8.5 the Ambient and Global Light Intensity is set in the Light Properties/Global Illumination panel. In LightWave 9.0 the Ambient is set in the Light Properties panel and the Global Light Intensity is set in the Render Globals panel.

Do another test render and compare your results to what you see in ZBrush.

The lighting change helped but it looks like the specular settings are a bit off. Change the Specularity to 25% and the Glossiness to 45%.

Do another test render and compare your results again.

From this point, you should continue to finesse the image and make any final adjustments necessary to the Displacement, Normal and Bump maps to get your image to match the sculpture in ZBrush. You can even continue to enhance your render by applying a cavity map. You can learn how to create a custom cavity map in #Creating a cavity/diffuse map.

Conclusion

Congratulations! You’ve successfully gone from LightWave to ZBrush and back again. That wasn’t so bad, was it? As you continue familiarizing yourself with the steps above, you’ll find that the process of working between LightWave and ZBrush is very simple. And best of all, the process is very open ended. As we proceed into the following sections, we’ll explore alternate workflows and advanced tips for getting the most out of your experience with these two programs.

Prepping your model for use in Zbrush

In this section we’ll talk in more detail about setting your model up for use with Zbrush. We’ll cover Zbrush’s requirements, as well as advice that goes beyond Zbrush’s minimal requirements, but is nonetheless essential for getting the best results from the program. We’ll also talk about the various techniques for working with UV maps in Zbrush.

Zbrush has two basic requirements for the models you import. The first is that they consist of quads or triangles. And to be honest, it should really just be quads. When you subdivide your object in Zbrush, quads are immediately subdivided into smaller quads. But if you have triangles, the first division only converts them into quads. Then they are subdivided into smaller quads on each successive division. So areas with triangles inherently have a lower resolution than other parts of the model. This can make modifications in those areas less accurate as there are fewer polys to work with. For this reason, if you’re going to use triangles, it’s best to hide them in inconspicuous parts of your object.

You’ll notice that N-gons are not supported. This means that polygons with more than 4 points will cause unwanted problems if you bring them into ZBrush. An easy way to check for n-gons is to use the Polygon Statistics panel. If the “>4 Verticies” option has a white + ornext to it, then you’ve got n-gons in your model. Make sure you convert these to quads or triangles before you continue.

The second requirement for bringing your model into Zbrush is that UVs not have overlapping geometry. If your UVs overlap, Zbrush can crash when you attempt to generate a displacement map. If you use Zbrush’s GUV or AUV Tiles, this won’t be a problem. But if you use any other UV type in Zbrush or if you create your UV in LightWave, there’s a good chance you’ll have overlapping geometry. Zbrush can help you identify overlapping UVs. That information is covered in #Checking for Overlapping UVs in ZBrush.

While Zbrush only puts the two aforementioned restrictions on the model you import, there are other more practical issues that can go a long way towards making your work in Zbrush more productive. In this section we’ll talk about them.

Optimizing the Polymesh

Good Polygon Flow

It’s easy to think of Zbrush as a magic modeling application. Its ability to handle millions of polygons and to paint deformations so effortlessly certainly lends to this notion. However it’s important to remember that Zbrush is really just a highly advanced subdivision modeling program. And as such, it operates on the same core principles which are found in other modeling applications. The chief principle here is that of proper polygon flow through the construction of good edge loops. The flow of polygons in your object will determine how the model gets subdivided. Having poor edge loops or inappropriately placed triangles will affect the subdivision and subsequently the quality of the deformations you’ll get in Zbrush and LightWave. While you can get away with bad flow in Zbrush, it bears noting that good flow will only enhance your work. Teaching you how to resolve problems of polygon flow is beyond the scope of this guide. However it is advisable that you study the work of skilled modelers to mimic their work and to ground yourself in the basics of human anatomy. The better LightWave modeler you are, the better Zbrush sculptor you will be.

Even distribution of polygons.

Most modelers strive to use the fewest number of polygons possible to achieve the proper results. However, in some cases, working with such few polygons can create models that look great when subpatched, but are nearly unrecognizable when not. This can produce two notable problems when working in Zbrush. The first comes from trying to adjust the mesh at subdivision level one. Since it’s best to work through the range of subdivision levels while sculpting in Zbrush, having a model that’s unrecognizable at level one can make it overly difficult to work with. The second problem comes when you apply UV textures. Since UVs are calculated at subdivision level 1, if you have too few polygons, you’re more prone to getting map distortion.

Before you export your object for use in Zbrush, hit the Tab key to turn on subpatches. If your model doesn’t look like it does when subpatched (with a bit less smoothing), you should consider freezing it at a low subpatch level before exporting it. This can be done by opening the General Options panel and setting the Patch Divisions to 2, closing the General Options panel and then pressing Ctrl-D.

Model Organization

If you’re working on a complex object, it can be helpful to organize parts of the model into groups before you bring it into ZBrush. You can do by selecting your polygons and choosing Create Part from the View tab in Modeler. Parts work like surfaces. A polygon can not have multiple surfaces; likewise it can not belong to multiple Parts. If you’ve already surfaced your object, you can make the Part creation easy by utilizing the Surfs to Parts command from the View tab in Modeler. When you import an OBJ into ZBrush that contains LightWave Parts, they will be interpreted as Polygroups. You can learn more about Polygroups in #Polygroups.

Model cleanup

Zbrush really likes to work with a single, solid mesh without open edges (i.e. holes) or unwelded points. Before you export your object, make sure you run the merge points command and delete any stray points that may be floating around your model from using tools like Merge Polygons. If you do have open edges, you should consider running the Tool/Geometry/Crease command before subdividing your object in ZBrush.

UV Map Preparation

In this section we’ll talk about the function of UVs in the LightWave / Zbrush pipeline. We’ll also talk about special techniques for using multiple UV maps in Zbrush to achieve greater levels of detail in your final object.

The functions of UVs in Zbrush

Zbrush uses UVs for three primary functions:Painting textures, generating displacement and normal maps, and sorting portions of your object into customized groups. ZBrush does not use UVs for its basic sculpting functions. This means you’re free to import your model and begin working on it without having to worry whether its UV map is ready. In the Quickstart Guide I showed you how easy it was to create a distortion-free UV map with Zbrush. But you’re not forced to use Zbrush’s UVs. You can use a LightWave UV map and even update it at any point during your Zbrush sculpting session. I’ll show you how to do this shortly.

How the OBJ file format handles UVs

Objects in LightWave can have any number of UV maps. Unfortunately, however, the OBJ file format is limited to using a single UV called the “OBJ_UVTextureMap.”

Obviously, if you’re only using one UV in Modeler for your entire object, this limitation will not pose a problem. However, that’s rarely the case. More often, multiple UV maps are created for different parts of an object with each one filling the available 0 to 1 UV coordinate space.

When you export an OBJ file with multiple UV maps, the OBJ exporter layers them on top of one another in a single UV called “OBJ_UVTextureMap”. As we’ve noted before, if your UV map contains overlapping geometry, it can cause ZBrush to crash. For this reason, it’s best to place each UV in its own distinct coordinate space. I’ll show you how to do this in just a bit.

Using LightWave UVs

Most of the time, using a GUV Tile UV created in ZBrush is the quickest and easiest way to get great results. However there are times when it’s more advantageous to set up your UV maps in LightWave. In this section we’ll talk about the circumstances under which you might want to use LightWave’s UVs over ZBrush’s.

If you do most of your texturing in ZBrush, then it probably doesn’t matter whether or not you use a ZBrush generated Tile UV. But if you want to use an external program like Painter or Photoshop, you’re going to run into a bit of trouble. If you’ve ever looked at one of the Tile UVs in Modeler, you know that they don’t look a thing like your object. Instead, they look like a crossword puzzle. This makes it nearly impossible to use your UV as a background guide for painting. For this reason, you may want to create your UV in LightWave.

Another situation in which LightWave UVs are a better option is when it comes to painting on inorganic objects. We all know ZBrush works wonderfully for characters. But you can also use it to texture objects such as furniture, appliances, aircraft etc. For rigid objects, I’ve found that GUV tiles produce undesirable artifacts. LightWave’s Atlas UV map, however, provides the perfect UV for these types of models.

Perhaps the biggest reason to set up UVs in LightWave is so you can use multiple UV maps. As was noted previously, the OBJ format can only handle a single UV. But as you will see shortly, you can work around this by setting your maps up in LightWave.

When using LightWave UVs, the following rules apply:

1. Make sure that you apply each UV map to a separate surface. You can not apply multiple UVs to a single surface as they will not be exported with the OBJ. Each UV must be applied to a separate surface and applied to one of the texture channels for that surface.
2. Make sure that you don’t have any overlapping UVs. I’ve mentioned this before, but it bears repeating. If you have overlapping UVs, it will cause Zbrush to crash when you try to generate a displacement map.

Setting up Multiple UVs for use in ZBrush

If you’re going to be texturing an entire character and you’re okay with using a single UV map for the whole object, then you can simply follow the steps outlined in the Quickstart guide. But if you want to maximize the amount of detail, you’ll be better off using multiple UVs. For example, you might assign one UV for the head of a character so that it can take advantage of the full 0 to 1 map space. You could then use another for the torso, and yet another for the arms and legs.

ZBrush can only create one UV map for each object. And the OBJ format can only hold one UV per object. This leads many people to believe that they can only use a single UV map for their work. But that’s not the case. To use multiple UVs, you must do two things:

1. Offset each successive UV map by 100% on the U axis.
2. Combine each separate UVs onto a single map

Let’s take a look at how to do this.

Open your object with Multiple UVs and copy each part that has a UV to separate layer. Open the Vertex Maps window from the Windows drop-down menu. Then switch one of your viewports to show the UV space and turn on the grid.

At this point, every UV should occupy the standard 0 to 1 UV space. We’ll leave the first layer’s UV where it is and we’ll offset each successive layer by 100%.

Click on the second layer and select its UV in the Vertex Maps window. Then run the Transform UV command from the Map tab. Check the Offset option to enable it. Set the U to 100% and leave the V at 0%. Finally, press OK. This will move the map a full space to the right.

Repeat this process for the next layer and increase the U offset value by an additional 100%. Since the last UV was offset by 100%, this one will be offset by 200%.

Repeat this again for each additional UV. Each successive Transform should see the offset increase by anadditional100%.

When you’re finished, select all of your layers. Then shift-select your UV maps. You should see each map in its own distinct space.