Volume Procedural Filtering

[Jordan Walsh]

Is there any techniques to do volume filtering on a VEX Volume Procedural?

I'm loading in volumes via the "volumesamplefile" node, then doing some procedural processing on them.

I guess there could be filtering done at two levels here, filtering the volume sampling (to reduce the stepping of lower res volumes) or filtering the render of the procedural (to reduce noise in the final render).

I'd be interested in both. 

I'm thinking something similar to object level Render/Shading/Volume Filter parm. This has no effect when rendering a procedural volume.

[ikarus]

You could build your own filtering function by sampling your volume multiple times in a foreach loop, offsetting the lookup position in a uniform manner, and averaging the sum of the values.  Optionally using a weighting method on your samples, based on a filter type.

[Jordan Walsh]

Thanks for the info!

I tried building a loop in cvex and without doing any variance of the sample position the result is quite a lot softer with 10+ samples. Perhaps this is a function of the renders ray variance? Im not sure. But if I add in a random position to the sample position I get unexpected results, blocky and shifted volumes.

volume_test.hip