Maya - Vertex normals editing while subdividing?

Lamo3D

subdividingHello! I'm working with Maya, and I was currently delving into the world of normals editing (for cases like foliage, interpenetration smoothing between meshes, separate character head from body cases, etc.).

I work in the animation industry, mostly using Arnold renderer, with models being subdivided with the Catmull-Clark algorithm, and I was wondering if we could use these normals editing techniques with the traditional subdivided rendering workflow.

We often have sharp visible inter-penetrations between say a floor and a wall, when two different sculpted floors collide between each other, and I was wondering if we could mitigate that, so I made a little test:

Here is my base case, it's two separate models making a harsh transition at the intersection, with their normals smoothed:

Then I edit the normals to get an averaged transition at the intersection (crude work just for the example):

Now that I'm satisfied with this, I find a spot where the transition is really smooth, and try to subdivide these two models (with the subdivision check "3" key in Maya), but the normals go back to their original state:

I checked how it looked being subdivided in Arnold (thanks to an Arnold object setting) and the same thing happens, it seems that whatever normals I had on my model, gets reset as soon as I apply a Catmull-Clark subdivision.

Do you have any idea if there is a way to remediate to that?

poopipe

I'm going to assume there's not - the standard (read, most obvious) method for subdivision of that type will require that normals are obliterated and since the effect is applied at render time rather than stored in the model there's probably not much you can do with the meshes themselves beyond collapsing them to geometry and editing the normals in some way

I have not poked at the problem so this is pure speculation

sprunghunt

This kind of shortcut is not worth doing. Especially if you're rendering in arnold and not using a realtime game engine. If you want the two surfaces to appear to be one model just weld them together so they are one model.