bdancer/vb25 — Issue #55: displacement mapping - "allow negative values" not working
Author: petersk
Created: 2011-10-13 17:38:52+00:00
State: open

The displacement mapping is not working properly - negative values from the texture are not used.

My setup is this:
I am using a 32 bit displacement map created in ZBrush4, tried both the tiff file saved straight from ZBrush, and an exr file converted with Picturenaut, tried also 16 bit tiff, exported directly from ZBrush.
Tried VRay standalone with core 1.9 and 2.0. Everything with the same results.

Exporter options:
In the render tab - displace/subdiv = on, settings at default. Tried all other possible settings here too.
In the texture tab - displacement type - normal (the same with 2d too), displacement settings at default, but the same with every other setting.
Note: use bounds is off. If I switch on and set bounds to -1 - 0 no displacement occurs, although there should be negative displacement only.
In the Bitmap pallete: Color space - Linear, Use input gamma = off, Gamma =1.0, Allow negative colors = on, Use data window = on, Filter = none. These are the correct settings, but with other settings the result is the same.

Here is an example render. You can clearly see that the area between the eyebrows and between the wrinkles on the forehead is absolutely flat. The displacement is strongly exaggerated to show better the effect.
http://www.pasteall.org/pic/18986