I am writing a modified ultimapper to convert tangent space normal maps from one mesh to another. The tool is needed because our tangent space normal maps are not encoded in the standard way and softimage's tools cannot be modified to support our proprietary tangent space. For prototyping I'm using the softimage tangent space and tangents property to do the transfer so I can check my math against ultimapper. Once I get a 1:1 match, I'll modify the logistics to support our proprietary stuff.
So far when the hi and low res meshes are untransformed I get a 1:1 match with ultimapper, but when I transform one or both meshes a wide discrepancy appears between my result and the softimage ultimapper result. The softimage result tends to be significantly brighter on the red and green channels, mostly on the green. In some cases, the colors are not even close to the same. The odd part is when I trace through the process step by step to debug, my numbers look correct both visually and mathematically. I'm in a weird situation in that I do not know who's result is more correct, mine or Softimage. Some of our artists have mentioned there have been some discrepancies compared to other commercial normal mapping tools (beyond flipping the Y axis). Has anybody had issues getting correct results from ultimapper when transferring tangent space normal maps between meshes? Matt
