Having problems with Arnold's Curvature map and scale

[Henri_Chretien1]

Scaling this model I'm working on does not scale the Curvature map applied to it accordingly. Or so it seems. I can't quite wrap my mind around it. The curves, nor anything for that matter, changes except the scale of the entire model. The bitmaps don't scale, the UVs don't scale, only the map changes. Any ideas?

Top: how it should look
Bottom: how it looks after scaling

[aaronfross]

Curvature is dependent on distance, and will be affected by scaling. Adjust the Radius attribute to compensate.

[Henri_Chretien1]

Alright, that's good to know. Thanks @Aaron Ross. That'll work for a given object, however I will be working with objects of different scales for this project and I will be forced to scale. Am I better off working with Curvature as an operator within the Data Channel modifier, or will I run into the same issue here as well? Thanks again!

[aaronfross]

You'll probably have a similar issue with Data Channel Modifer, which has a Scale parameter similar to Arnold's Curvature Radius. One thing is for sure, DCM will involve more work and much slower performance.

If you're doing a lot of scaling, maybe create a simple expression or parameter wiring to increase Curvature Radius as a factor of transform Scale.

[sergeyklesov]

Hi Henri,

Maybe something similar can be created in Max?

[Henri_Chretien1]

That appears to be exactly what I'm after @Sergeyklesov Sergeyklesov However, I can't seem to find any tools or workflows in Max that allows me to load an object's parameters into the Material Editor for use with material nodes. Any thoughts on what sort of transform node to use for such a parameter wiring @Aaron Ross ? From what I see listed only transform maps for 2D manipulation of nodes are supplied with Arnold (like Matrix Transform). One solution I guess is to export the Curvature map as a bitmap and use that. Sort of a worst case scenario though. Thanks again for all your help 🙂