Sculpting A Skull With Image Planes

From ZBrush Info

Contents 1 Introduction 2 Setup The Image Plane 3 Bringing The Image Plane Into ZBrush 4 Sculpting

Introduction

In this tutorial we will look at sculpting a skull using image planes. We will use:

• SubTools
• Transparency
• Masks
• 3D sculpting brushes

Setup The Image Plane

To begin this tutorial, we must first prepare our image plane. The second image from the top is a template that you can use to align your front and your side view.

1. Click the image to open a larger view, then right click the larger image and save it to disk. Call it ImagePlaneTemplate.jpg
2. Then, open ImagePlaneTemplate.jpg in Photoshop as well as the images you would like to use for front and side views.
3. Align your front view in the section marked Front in ImagePlaneTemplate.jpg.
4. Align your side view with the section marked Side in ImagePlaneTemplate.jpg.
5. You must keep each view in a square formatting and placed side-by-side.
6. Save your image plane with an easy to remember label.

Our final image is below.

Bringing The Image Plane Into ZBrush

In this section we will bring the image plane into ZBrush as a SubTool and use Transparency to begin sculpting. The skull image is added to the plane using polypainting.

1. To make this easy, download the ready-prepared ztool here: Skull_ImagePlaneX.zip
2. Unzip the zip file and load the ztl using the Tool: Load Tool button
3. Draw the ZTool on the canvas and press t on the keyboard to enter Edit mode
4. Press Transform: Transparency to turn on Transparency

After adding the image plane, you may want to enable double-sided viewing. By default, ZBrush does not display the backside of the mesh where the surface Normals are not facing you. To enable this press Tool: Display Properties: Double.

If you do not want the image plane to share the same material as your model please follow the steps below:

1. In Tool: SubTool palette, select the X-plane subtool
2. Select the desired material. See below if you wish to use the Flat Color Material.
3. Select M in the Draw Palette.
4. Press Fill Object in the Color Palette.

Note: you can assign the Flat Color material to a surface however, you have to do the following steps:

• select the Flat Color material.
• Press the Save button in the Material Palette and save it to disk
• Select a Material that is not likely to be used like a Fast Shader.
• Press the Load button in the Material Palette, and load in the Flat Color material.

This newly loaded Flat Color material will allow you to assign it to an object. When you are done, make sure to select your main mesh, and change back to your modeling material, such as Red Wax.

You might ask why? The Flat Color material resides in the 00 index of the Material palette. This allows it to be used to unassign a material to an object. Effectively, by assigning a material of 00 to an object it assigns no material to the object.

Sculpting

Rotate the model to the side view by clicking outside the model and dragging to the left. While dragging you can press SHIFT to lock the model to a side view. Select the Move Brush from the Brush Palette. Move the edge of the model in to align with the image.

Turn to the front view and press Draw:Perspective. We are using Orthographic views so we will set our Draw: Focal Length to around 100 to remove as much of the perspective distortion as possible. If your image comes from photographs, simply adjust your Draw: Focal Length to the level that works for you.

Still using the Move brush sculpt the Front view. Focus mostly on the contour.

Don't get into the interior forms yet.

Switch to the Standard Brush in the Brush Palette and begin working on some of the internal forms.

Moving back and forth between the side view and the front view will help you judge your progress.

Here we have gotten farther along with the forms but we are still keeping it loose and very general. The key is to know what you want to put in there but only suggest it at this stage. We will slowly make it more and more 'realized'.

At about this point, we start sculpting the orbit of the eye. You can use the Move brush and pull the hollow of the eye backward or you can just use the Standard brush with Zsub on. Remember to check the front and side views often to see if you are on track.

In the video we use masks. To learn more about Masks visit the Mask page and the following video tutorials:

• Sculpting With Masks by Cesar Dacol Jr. (Quicktime required).
• Sculpting Tips by Thomas Mahler (Quicktime required).
• Modeling With Your Texture by Ryan Kingslien (Quicktime required).

Here we have begun to bring the forms into focus a little more. The cheekbone is clearly marked. The Jaw is defined by the hard line and everything is still lining up with our image planes just fine. At this stage we are using the Clay Brush set to around 30. We are using the Freehand Stroke and Alpha: Brush 28.

Now we divide our model to get more geometry to work with. Press Tool: Geometry: Divide. Learn more about it in the Geometry Sub-Palette.

Then start to use the RakeSmooth brush in the Macro: Macros: RapidBrushes sub-palette. The RakeSmooth brush is a a preset of several settings: The Clay brush, a custom alpha, Freehand stroke and others.

The RakeSmooth brush is great for smoothing forms together and really getting in and developing the details of a model.

Here we use the Ramtool brush preset. This is another RapidBrush macro. This brush creates a very clean and deep stroke that we use to clearly define the temporal line and the outer edge of the orbit of the eye.

Going back to the RakeSmooth tool we further develop the skull. We have refined the form and made the nasal area more clear.

Our final image shows the development we have done to date. The major forms are outlined. We could now go further and create more specific form such as the teeth.