Corona Curvature Map playground!

We have the long-awaited Corona Curvature Map in our newest daily build!
You can check the full changelog and grab the installer here: https://forum.corona-renderer.com/ Corona Renderer 8 for 3ds Max - Daily Builds Changelog #msg194357

This is an early implementation and it may still change based on your feedback, so please let us know what you think about it, what is great, and what isn’t.
We are also very interested in the differences you notice between the Corona AO and Curvature, and when exactly you would choose to use which.

Basic usage:
Create a new Corona Curvature Map in the material editor.
Plug it into any material property you wish, or use it as a mask to mix various properties/materials.

An example where AO and Curvature produce a similar result:

An example where AO and Curvature produce a visibly different result:





I’m very happy to finally get Corona curvature! Few small notes from initial testing:

  • default max distance of 100 units is way too much, i think 1 unit would be more sensible default.
  • distance should be mapable, like it is in CoronaAO.
  • someone already mentioned issue, where convex colour can’t be darker than base colour.

I’ll duplicate it here again, please add an option to ignore the bump :smiley:

Hi devs, thank for new CurvatureMap, it works fine with black base color but doesn’t with white. Please see attachment for more details… Or I do smt. wrong?

Hi,

Reported and we’ll look into it.

Thanks.

(Report ID=CRMAX-1252)

Thanks, I have logged these and will discuss them with the devs.

(Report ID=CRMAX-1253)
(Report ID=CRMAX-1254)

Hi,

I have logged this too. Will discuss with the devs.

(Report ID=CRMAX-1255)

Some tests. Basic metal with falloff vs metal with curvature. I think the latter looks better, but also is slower to render.


Bug report: artefacts appear on thin wall mesh, when curvature’s max distance is larger than wall thickness.

Nice catch, reporting it.

(Report ID=CRMAX-1260)

Hi!
I would like the parameter to take into account the “smoothing group” Or the angle of inclination of the polygon.

My tests shows that curvature is taking into account smoothing groups. Angle threshold would be useful control indeed.

Couple stylised materials with curvature.


Great, thanks for added Blend method Looks much better. It would be awesome to have AO effect with intersecting meshes (different objects).

Adding a curvature map to material causes an error and crash while IR is going on

Hey,

I can’t reproduce this one, can I see the rest of your material tree or even better can you send the scene over?

Thanks,

Rowan

Tested out the new curvature map. Pretty cool.

Though… am I missing something?

I thought the entire point of the curvature map was to control the angle at which it happens? There isn’t any control over it’s parameters. How is this any different from AO? (other than it’s only self-referential).

Sorry if this is really dumb…

Hi Scionik,

Thank you for reporting that, we’ve managed to reproduce the issue.

Kris

(Report ID=CRMAX-1277)

From my layman’s perspective, AO looks for occlusion, it doesn’t care about surface flatness. Curvature map does the opposite - it looks for surface flatness and doesn’t care about occlussion. The fact that highly curved surface is almost always self occluding, makes AO look similar to curvature, but in fact those are quite distinct maps and their output can be tuned to serve different purposes. Angle threshold control would be interesting to have and already has been requested, but to be honest i didn’t see such control implemented in any curvature map (not that i saw many of them), maybe it’s technically hard to implement, or its usage is not very practical?

Great, thanks