ZBrushCentral

Hard Surface Normal Maps

ZBrush Usage Questions
#1

Im wondering what the recommended workflow for exporting normal maps for hard surface models is. Here is the problem Im having:

  1. I create a sphere, subdiv it, and sculpt a clean line in it (see fig.1)
  2. I return to subdiv level 1, and the sphere is not smooth anymore (fig.2)
  3. after smoothing the sphere out again, I return to the highest subdiv, and the clean line is messed up (fig.3)

My temporary solution is:

  1. go to subdiv 1 and smooth out the sphere.
  2. make sure not to return to the highest subdiv, and create the normal map. if I dont return to the highest subdiv, the changes to the low res do not effect the high res, so the normal map turns out fine
  3. undo the smoothing of the low res sphere and continue working.

For complicated shapes, this is a pain to have to smooth out the lowest sub div every time I want to see the normal map in Maya.
I tried to use GoZ to keep the smooth low res shapes in tact in a maya scene, but when I return them to zbrush, their changes permeate through to the hi res sculpts and mess them up.

So now the only reasonable solution I’m seeing is to use an external program like xnormal. I don’t like this solution and Im wondering if anyone else has a workflow that allows everything to stay in zbrush.

thanks!

Attachments

spheretest.jpg

#2

I think the workaround is to make a morph target of your base mesh, then before you make the normal, go back to the morph target.

#3

xNormal is your best bet IMHO.

#4

I’d second the xnormal recommendation even though it’s not what you may want to hear. Tangent based normal maps require quite a few variables in place for the best result possible, especially in hard surface models which tend to have more sharp edges present. Xnormal will let you specify the tangent basis of the mesh, while supporting custom vertex normals (which should be split along 90’ edges, with matching UV borders).