Working with ZBrush Data
The workflow to produce nice models in KeyShot is partly based on the background environment image which will produce the light, as well as the materials applied to you model.
In KeyShot, you have complete freedom to change the lighting, use ZBrush materials already applied to your model and also use anything from the rich material library provided within KeyShot.
Applying materials to a model in KeyShot is done in two different ways:
- Drag a material from the library and drop it onto the model. The ZBrush material applied to the model will be replaced by the selected one and this change will also be applied to all other SubTools which have the same ZBrush material.
- Drag a material from the library and drop it onto the model of your choice in the KeyShot scene tree. In this case, the material change will only be applied to that specific SubTool.
This way of working gives you great flexibility. If you are working with a single model which only needs one material, you can simply do a quick drag and drop from the library onto the model, no matter how many SubTools it might be comprised of. On the other hand, if you want to keep the ZBrush materials for some SubTools while using KeyShot materials for others, you can drag materials onto the scene tree. Alternatively, you can define different Materials/MatCaps in ZBrush before sending it to KeyShot.
1. Material Priority
When working with materials in either ZBrush or KeyShot, the last material applied in either program will have the priority when doing an update of the scene from ZBrush to KeyShot.
In other words, if you sent a scene to KeyShot and changed the materials there, those materials would remain even if you do some edits in ZBrush and perform a new render. However, if you then changed a material in ZBrush that would be reflected in your next KeyShot render. KeyShot will always use the most recently applied material for any SubTool, regardless of whether that material was applied in ZBrush or in KeyShot.
2. Multiple Materials in Action
If you wish to apply different KeyShot materials to different parts of your model, you will generally first want to assign separate ZBrush materials to each part. Applying a material in ZBrush always means being able to apply a KeyShot material to the same location.
If you want separate KeyShot materials on different parts of the same SubTool you would have to:
- Select your SubTool.
- Select the first ZBrush Material/MatCap.
- Select Draw >> M or MRGB.
- Click Color >> Fill Object to attribute the material to all the SubTool’s polygons.
- Use the Marquee or Lasso selection brush (Ctrl+Shift+click drag) to hide the parts of the model that you want to continue using the first material.
- Select another material.
- Color >> Fill Object to attribute the material only to the visible polygons of the model.
- Repeat the last few steps for any other materials.
- Show all the polygons of the model with by Ctrl+Shift+click on the document or by clicking Tool >> Visibility >> ShowPt.
- Now send your model to KeyShot.
- If you select a material and drag it over your model without releasing the mouse button, portions of the model should become highlighted based upon which ZBrush material was assigned to that portion.
- Now you can define which KeyShot material to apply to each section simply by dropping it on the desired highlighted area.
3. Working with Texture and PolyPaint
The KeyShot for ZBrush Bridge fully supports both textures applied to your model and ZBrush PolyPaint. If your SubTool has both an applied texture and PolyPaint, the Bridge will transfer whichever is currently visible in the ZBrush document. (Texture takes priority unless it is turned off in Tool>Texture Map.)
You can also apply KeyShot materials to your model to replace the ZBrush materials. By default, doing this will completely replace the material and its information of color/texture. To preserve the texture or PolyPaint information you need to hold the Alt key while dragging and dropping the KeyShot material to its destination.
Keep in mind that not all KeyShot materials support vertex shading or texture mapping! If you choose to use such a material it will be impossible to preserve the incompatible data in that part of the model. In those cases it is not possible to add the Color/Texture information in KeyShot except by changing the type of material but this may make some physical properties of the material disappear.
4. Working with Surface Noise
Any Surface Noise applied to your model is fully transferable to KeyShot. During the rendering process, ZBrush applies a tessellation to the whole model before then displacing the geometry to correspond with the procedural noise. This automatic operation means that you don’t need to apply your surface noise to the mesh for rendering purposes.
The quality of the tessellation and as a result the quality of the produced noise is defined by the Tool>Display Properties>BPR Settings>3D Noise Max Resolution slider. This sets (in millions) the maximum number of polygons that ZBrush can add to your model during the rendering process.
Please refer to the Surface Noise documentation for more information.