rheniser Posted January 19, 2015 Share Posted January 19, 2015 In PRMan, the "radial-bspline" filter is specifically designed for optimally filtering displacement textures. Is there an equivalent in Mantra? If not, is one of Mantra's Filter Types better suited for displacement maps? Quote Link to comment Share on other sites More sharing options...
kleer001 Posted January 19, 2015 Share Posted January 19, 2015 I think it depends on your uses. When I was trying to match a high detail and high displacement map with something out of ZBrush I had to turn off the filtering. Then it 95% match pixel/pixel. All the active filtering just blurred or mangled the map for me. 1 Quote Link to comment Share on other sites More sharing options...
rheniser Posted January 19, 2015 Author Share Posted January 19, 2015 (edited) Turning off filtering altogether opens us up to aliasing, which is particularly noticeable for displacements when object/lights move through the scene. I thought the radial basis spline (B-spline) was the preferred choice for displacements as it is a piecewise polynominal function that better captures the high frequency detail common in displacement maps. I don't see filter amongst the Texture vex node's filter type options (Bartlett/Triangular, Sinc Sharpening, Hanning, Blackman, Catmull-Rom, & Mitchell) that would do something similar. Edited January 19, 2015 by rheniser 1 Quote Link to comment Share on other sites More sharing options...
kleer001 Posted January 20, 2015 Share Posted January 20, 2015 Maybe try upping the resolution of your maps? Man, I got nothin. Quote Link to comment Share on other sites More sharing options...
Jason Posted January 20, 2015 Share Posted January 20, 2015 If you have some convincing evidence of the benefit of such a filter, it might be worth an RFE to Side Effects, perhaps? 1 Quote Link to comment Share on other sites More sharing options...
pbd Posted January 20, 2015 Share Posted January 20, 2015 (edited) Actually there is no such thing as a "perfect filter for displacement" It really depends from the displacement texture "contents", the texture can be a procedural or an actual file texture (ultimately also the procedural gets mipmapped prior rendering but it should have its own filtering too within the procedural code). Think about a texture as a "signal"or (just imagine a texture is a 2D math function: there is no one-filtering-to-rule-them-signals all. And as it has been said the 'no filtering' option (which is basically point sampling) is definitely not a good choice. The best you can do is: - use a 16 bit float depth texture (exr half) or a float 32 bit EXR/TIFF - keep resolution reasonably high - edit: you might want to check in case you use a procedural if its functions are properly anti-aliased Edited January 21, 2015 by pbd 1 Quote Link to comment Share on other sites More sharing options...
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