ZBrushCentral

UVmap borders and displacement maps

ZBrush Usage Questions
#1

hi, i need help with something…

i have a head model made of no more than 500 polys, all quads, and uv maped before imported to Zb.

i`ve subdivided it 4 or 5 times, and detailed it with projection master. Then tryed to generate a displacement / bump map out of it…
everything worked great, except for those parts where the uv map previously asigned to the mesh is cut and continues somewhere else… im not explaining quite well here… so i attach two images to make it clear
Untitled-1.jpg](http://javascript<b></b>:zb_insimg(‘6102’,‘Untitled-2.jpg’,1,0))

well… there u can see, where the uv mapping discontinues, so does the displacement map
anyone had the same problem, or has an idea how to fix this ???

tnx

Attachments

Untitled-2.jpg

#2

It’s hard to tell for sure, but from the image it looks like you have four polygons that are actually mapped twice, and those polygons are the ones that are where the problem is happening. It could certainly explain what you’re experiencing.

#3

hmmm… nup, actually, every single poly has its own place in the uv map…

but tnx anyway

#4

Things you may want to try:

  1. In your rendering application, experiment with the render settings. One important factor is the sampling method and the amount – if any – of blurring applied to the map. Correct settings will show little or no gaps between UV regions. MIP-mapping and texture anti-aliasing are probably not good choices when applied to displacement maps.

  2. Reapply UV mapping with UV borders hidden in the areas of the mesh which are not easily visible. Or use ZBrush’s AUVTiles or GUVTiles.

  3. Apply a .5 pixel offset to the UV coordinates. Fractional pixel location is not interpreted equally by all applications. Even a small shift of UV coordinates will result in a visible gap at UV borders. Try applying -0.5 pixel or +0.5 pixel offsets to the UV coordinates in the rendering application and retry the displacement rendering. When you find the best offset, use the same setting with other displaced meshes.

  4. Use a higher subdivision level as your exported and displaced mesh. In other words, if subdivision level 1 is rendered with visible gaps due to mesh folding or excessive displacement, switch to level 2 or level 3 to generate the displacement map and then export that level to the other renderer.

One final note: Displacement rendering requires exact settings of rendering parameters and a good understanding of displacement mapping. Each rendering application is different in the way that it interprets displacement maps. You will need to experiment to find the settings which fit your rendering application and workflow the best.

#5

I see that aurick copied and pasted the same reply here that he did in this thread.
Maybe he will have more info tomorrow.

#6

Did any of those suggestions help?

#7

hi, and tnx a lot first of all…

actually, i didn´t had time yet to try the displacement maps again.
I´ll let u know as soon as i get any result

tnx again