Noise and topology

[jim c]

I'm trying to generated noise that flows along the topology of the geometry. But I'm missing something obvious about how to do that.

The red arrows indicate how I'd like the noise to flow. The geo is generated by using the polywire SOP. The only other thing I can think of is using COP to generate a texture map with noise and then read the data from that.

 

[konstantin magnus]

if your tree has UV coordinates you can us them as input for your noise.

bark_uv.hipnc

[f1480187]

I don't think it is trivial task with noise generation. Or I missed the trick. Warping noise will produce very noticeable artifacts on warped areas. It will work for some degree of quality, though. You might need to center time within the shot by using negative initial values for offset, to minimize offset distance and therefore warp artifacts.

You probably still have an initial curve. If not, find shortest path can be used to rebuild rough tree skeleton. Compute a tangent using PolyFrame, transfer it to the tree. Build rotation matrix using tangents and point normals. You can warp noise in local space by multiplying noise offset value by this matrix.

noise_warp.hipnc

As another idea, you may try to make curve force and deform surface by nearby flying particles.

[jim c]

Thanks guys, both of these are real interesting ideas.