ZBrushCentral

Displacement Values decreasing in Value

ZBrush Usage Questions
#1

I did search the forums for similar problems, but couldn’t find any thread about it.

Basically I have been sculpting displacements for a model and I have up till now exported displacements that seemed OK, but were a bit weak. The reason for this, I believe, is because when I sculpt in a higher subdiv level and step back, the base mesh is altered by the sculpt and the distance between the base and the sculpt is not that high.

Therefore I stored the Morph Target of the initial base mesh. When I try to export a displacement map now it is really weak… we’re talking 1/1000 style. This goes even if I do not switch to the base MT so I must have been doing something else to affect it. I think it is tool dependent since it does not seem appear with a test sphere. Also, if I append this tool to another tool that has the disp working and I try to export a new one it works. I will continue working on the model like this for now, but I really, really want to figure out what I did wrong because I do not want to deal with this later in the middle of the production… So what could I have done that is tool specific to provoke this?

My extraction settings:
Adaptive: Off
DSubPix: 0
SmoothUV: On
Flip V: On
3 Channels: On
32 Bit: On

I’m pretty sure these settings are the ones I have used earlier, but since this happened from one version to another I must have done something wrong setting wise or something. Does anyone have experience with this? Or if people could post their checklists when exporting Disp so I might see something that is wrong compared to my scene?

Check the image to see the major difference in the disp. You can almost not see anything on the one to the right…

[zbrush_th.jpg]

I can not work any more until I solve this issue so all help, even though you might think it’s too obvious, please shout out…

-M

#2

I just love how you always find it out 10 minutes after you ask…
The problem was that the scale in the export settings was reset to 0…
I’ll leave the thread in case anyone else has the same problem.

#3

You can’t tell how good a 32bit displacement map is by looking at it, still less by comparing it to a 16bit map in Photoshop. If you open a 32 bit map in PS then it quite likely will look as if there’s not a lot of detail there. This is because the range of values in a 32 bit map is much greater than 16 bit (65536 times greater!). The only real way of telling whether a 32 bit map is good is by loading it into your render app.

Also, when rendering a 32 bit map you should set the Tool>Displacement>Mid slider to zero. See here:
https://support.pixologic.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=42

HTH,

#4

Thanks Marcus. The first step that got us thinking was trying it out in RenderMan, but now I think I’ve solved it. Gonna try some renders now and see if my new extracts are working :slight_smile: Thanks for the link btw.