After I had some trouble with rendering displacement maps from Zbrush,
I wrote a tutorial describing my workflow between XSI and Zbrush:
1) First model your basemesh in XSI, it´s a good idea to have a look at the
edge-flow, too. Or you may have to retopologize your model later.
2) Layout your UV-coordinates. If you plan to use multidisplacement, the UV-groups must
be arranged horizontally in spaces of one unit:
3) Export your model as .obj and import it into Zbrush.
4) Detail your model as you like.
5) When you are done detailing and want to texture the model from within Zbrush,
disable the UVs and start polypainting.
But don´t forget to reimport your .obj to get your UVs back! 🙂
6) For my renderings in XSI I tend not to use the lowest subdivision level, because they
are too blocky. So I export a higher version and delete the lower levels afterwards:
7) Now to the important steps:
Create your Texture on the highest subdivision level unsig Texture-> color to texture.
Always hide all but one UV-group.
Do this with all UV-groups.
8) Create your displacement-map with the multidisplacement plugin.
The following options seem to work best:
9) Back in Softimage import the object and select one of your displacement maps.
10) If you didn´t change the import options, all UV-groups will be imported as separate objects and there will
be a rendertree for every object.
Set the right displacement and color maps in the rendertree.
Maybe you need to change the displacement ranges, too but for me a range from -0.5 to 0.5 seems to
work pretty well.
1) You should now merge your objects back into one and also merge the materials and UVs.
Every material will end up on a separate cluster.
Change the subdivision render level to 1.
12) Change the displacement options of the new object:
13) Now do a test rendering. If you don´t see any displacement you may need to set the mesh splitting
factor in the render options to a higher value.
14) Now it´s time to fine-tune your displacements and your rendertree…
Here is the final image: