Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Daily Builds => Topic started by: maru on 2022-01-27, 14:13:18

Title: Corona Curvature Map playground!
Post by: maru on 2022-01-27, 14:13:18
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/index.php?topic=33839.msg194357#msg194357

(https://forum.corona-renderer.com/index.php?action=dlattach;topic=35473.0;attach=160004;image)

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:
https://corona-renderer.com/comparer/ZYyww6

An example where AO and Curvature produce a visibly different result:
https://corona-renderer.com/comparer/fHEmkv
Title: Re: Corona Curvature Map playground!
Post by: romullus on 2022-01-27, 14:47:01
I'm very happy to finally get Corona curvature! Few small notes from initial testing:
Title: Re: Corona Curvature Map playground!
Post by: marchik on 2022-01-27, 20:18:49

I'll duplicate it here again, please add an option to ignore the bump :D
Title: Re: Corona Curvature Map playground!
Post by: scionik on 2022-01-27, 21:07:05
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?
Title: Re: Corona Curvature Map playground!
Post by: rowmanns on 2022-01-28, 09:18:54
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)
Title: Re: Corona Curvature Map playground!
Post by: rowmanns on 2022-01-28, 09:24:29
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.
Thanks, I have logged these and will discuss them with the devs.

(Report ID=CRMAX-1253)
(Report ID=CRMAX-1254)
Title: Re: Corona Curvature Map playground!
Post by: rowmanns on 2022-01-28, 09:25:04

I'll duplicate it here again, please add an option to ignore the bump :D
Hi,

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

(Report ID=CRMAX-1255)
Title: Re: Corona Curvature Map playground!
Post by: romullus on 2022-01-28, 20:05:29
Some tests. Basic metal with falloff vs metal with curvature. I think the latter looks better, but also is slower to render.
Title: Re: Corona Curvature Map playground!
Post by: romullus on 2022-01-29, 20:04:26
Bug report: artefacts appear on thin wall mesh, when curvature's max distance is larger than wall thickness.
Title: Re: Corona Curvature Map playground!
Post by: GeorgeK on 2022-01-31, 07:29:02
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)
Title: Re: Corona Curvature Map playground!
Post by: Feodor on 2022-01-31, 10:43:43
Hi!
I would like the parameter to take into account the "smoothing group" Or the angle of inclination of the polygon.
Title: Re: Corona Curvature Map playground!
Post by: romullus on 2022-01-31, 20:38:24
My tests shows that curvature is taking into account smoothing groups. Angle threshold would be useful control indeed.
Title: Re: Corona Curvature Map playground!
Post by: romullus on 2022-01-31, 20:39:22
Couple stylised materials with curvature.
Title: Re: Corona Curvature Map playground!
Post by: scionik on 2022-02-03, 12:59:17
Great, thanks for added Blend method Looks much better. It would be awesome to have AO effect with intersecting meshes (different objects).
Title: Re: Corona Curvature Map playground!
Post by: scionik on 2022-02-03, 13:02:30
Adding a curvature map to material causes an error and crash while IR is going on
Title: Re: Corona Curvature Map playground!
Post by: rowmanns on 2022-02-03, 13:46:05
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
Title: Re: Corona Curvature Map playground!
Post by: aaouviz on 2022-02-03, 13:54:18
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...
Title: Re: Corona Curvature Map playground!
Post by: Kris H on 2022-02-03, 15:27:26
Adding a curvature map to material causes an error and crash while IR is going on

Hi Scionik,

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

Kris

(Report ID=CRMAX-1277)
Title: Re: Corona Curvature Map playground!
Post by: romullus on 2022-02-03, 16:28:02
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).

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?
Title: Re: Corona Curvature Map playground!
Post by: scionik on 2022-02-03, 17:06:59
Adding a curvature map to material causes an error and crash while IR is going on

Hi Scionik,

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

Kris

(Report ID=CRMAX-1277)

Great, thanks
Title: Re: Corona Curvature Map playground!
Post by: aaouviz on 2022-02-04, 08:50:12
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).

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?

Ok, thanks. Well please consider me +1 for angle threshold. Cheers
Title: Re: Corona Curvature Map playground!
Post by: marchik on 2022-02-08, 00:17:28
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)
Title: Re: Corona Curvature Map playground!
Post by: GeorgeK on 2022-02-08, 09:13:20
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)

Hi, we have this logged.

(Report ID=CRMAX-1255)
Title: Re: Corona Curvature Map playground!
Post by: rowmanns on 2022-02-09, 16:23:36
Adding a curvature map to material causes an error and crash while IR is going on
Hi,

This is fixed in the latest daily: https://forum.corona-renderer.com/index.php?topic=33839.msg194990#msg194990

Thanks,

Rowan
Title: Re: Corona Curvature Map playground!
Post by: badpanda on 2022-02-27, 03:38:15
Had some fun with the curvature map.
Love it!
Title: Re: Corona Curvature Map playground!
Post by: Rhodesy on 2022-03-24, 10:37:30
Is it possible to use displacement with the curvature shader? I'm after a chipped edge look. I know this wasnt possible with AO but I wondered if curviture worked on different principles. I've tried plugging the curvature shader directly in to the displacement channel and also using it as a mask in a layer shader but nither actually displace the geometry they just create a bit of a fuzzy mess around the edges.

EDIT: on closer inspection of the normal pass the edges are showing the texture but only as a bump. The mesh isnt displaced.
Title: Re: Corona Curvature Map playground!
Post by: marchik on 2022-03-24, 14:11:30
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)

Hi, we have this logged.

(Report ID=CRMAX-1255)


As far as I understand, there are no plans to implement this feature yet? because the color spread option doesn't help much
Title: Re: Corona Curvature Map playground!
Post by: marchik on 2022-04-12, 08:22:00
As far as I understand, there are no plans to implement this feature yet? because the color spread option doesn't help much
I guess I'll ask again, is it technically so difficult to implement this function of ignoring bump and possibly displacement? when setting up any shader with a fine texture, it is almost impossible to achieve a clean result, at the moment this map is only suitable for a very limited range of tasks with organic shapes for "dirty" results

Title: Re: Corona Curvature Map playground!
Post by: maru on 2022-04-12, 11:40:37
As far as I understand, there are no plans to implement this feature yet? because the color spread option doesn't help much
I guess I'll ask again, is it technically so difficult to implement this function of ignoring bump and possibly displacement? when setting up any shader with a fine texture, it is almost impossible to achieve a clean result, at the moment this map is only suitable for a very limited range of tasks with organic shapes for "dirty" results

Thanks for the reminder, but I don't think this is possible to be added to V8.

(Report ID=CRMAX-1255)
Title: Re: Corona Curvature Map playground!
Post by: Rhodesy on 2022-04-12, 11:44:27
.. While you're here Maru. Can the curvature shader be used with displacement for displacing edges? I can't seem to get it to work..
Title: Re: Corona Curvature Map playground!
Post by: marchik on 2022-04-12, 11:47:38

Thanks for the reminder, but I don't think this is possible to be added to V8.

(Report ID=CRMAX-1255)

thanks Maru for the answer and for your attention, I remember that you logged the request a long time ago, just each time setting up the shader where I need a clear mask around the edges, I am happy to remember that now we have curvature map and every time I get upset when I can’t achieve an acceptable result :D
Title: Re: Corona Curvature Map playground!
Post by: maru on 2022-04-12, 13:22:03
.. While you're here Maru. Can the curvature shader be used with displacement for displacing edges? I can't seem to get it to work..

I don't think so. It's a render-time effect, like AO.
You can do this for example with Corona Distance, because it is evaluated before rendering. But some other effects aren't.
Other than that, even if we would somehow make it work, then how would you apply a curvature map to a displaced surface? :)



Thanks for the reminder, but I don't think this is possible to be added to V8.

(Report ID=CRMAX-1255)

thanks Maru for the answer and for your attention, I remember that you logged the request a long time ago, just each time setting up the shader where I need a clear mask around the edges, I am happy to remember that now we have curvature map and every time I get upset when I can’t achieve an acceptable result :D

Sorry, I'm afraid I can't help here. :(
Maybe this would be possible using a Layered Mtl? (the top layer with Corona Curvature would not have any bump)
Title: Re: Corona Curvature Map playground!
Post by: Rhodesy on 2022-04-12, 13:31:11
.. While you're here Maru. Can the curvature shader be used with displacement for displacing edges? I can't seem to get it to work..

I don't think so. It's a render-time effect, like AO.
You can do this for example with Corona Distance, because it is evaluated before rendering. But some other effects aren't.
Other than that, even if we would somehow make it work, then how would you apply a curvature map to a displaced surface? :)




Thanks Maru. that's a shame, I was hoping that it wasnt a post effect like AO and could be used as a mask in a layered mat with a displaced material only effecting the edges where a curviture shader is making a mask. Never mind. maybe v9 might find a way! Cheers
Title: Re: Corona Curvature Map playground!
Post by: Dionysios.TS on 2022-04-12, 14:05:29
Hi to all!

I am having some free time today and I am testing the Curvature map.
I've notice one thing, the map generally produces a blur result so the materials or colors it mixes are always mixed softly. Whatever values I use, the result is always soft/blurred.
I am trying to achieve something like the images I've attached: Curvature_Example_01 and 02. My result (3ds_Max_Screenshot) is always too soft! I used on purpose the light blue and red materials and where the red is applied by the curvature map,
is now pink. In a few words, I can't achieve a very net and clear curvature map result!

Is this a limitation now? Am I doing anything wrong???

Thanks,

Dionysios -
Title: Re: Corona Curvature Map playground!
Post by: Dionysios.TS on 2022-04-12, 14:38:20
FYI, applying a color correction map on the top of the curvature map boost up a lot the effect!

See attached example...

Thanks,

Dionysios -
Title: Re: Corona Curvature Map playground!
Post by: Dionysios.TS on 2022-04-12, 14:51:39
Here is a result which is close of what I would like to achieve but is possible only by applying a Color Correction map on the Curvature map.
I am not sure is the corret way to do this thing in any case...

Thanks,

Dionysios -
Title: Re: Corona Curvature Map playground!
Post by: Dionysios.TS on 2022-04-12, 15:37:40
Here is another result by using a cellular map and always color correction on top of the Curvature map.

Thanks,

Dionysios -
Title: Re: Corona Curvature Map playground!
Post by: Dionysios.TS on 2022-04-12, 16:01:37
Last example for today, I swear! :)
Title: Re: Corona Curvature Map playground!
Post by: maru on 2022-04-12, 16:29:42
To get sharper edges, you can boost the "color spread" and "directionality" values and/or plug your Curvature map into a 3ds Max "Output" map and play around with the curve there.
Title: Re: Corona Curvature Map playground!
Post by: Dionysios.TS on 2022-04-12, 16:33:29
To get sharper edges, you can boost the "color spread" and "directionality" values and/or plug your Curvature map into a 3ds Max "Output" map and play around with the curve there.

Yes and thanks, I actually find out that an additional Output channel is needed to do it right!

Thanks agian,

Dionysios -
Title: Re: Corona Curvature Map playground!
Post by: marchik on 2022-04-13, 06:18:26
Sorry, I'm afraid I can't help here. :(
Maybe this would be possible using a Layered Mtl? (the top layer with Corona Curvature would not have any bump)

yes, but then the meaning of its use is lost, I need it as a mask and not as a color, I hope this will be implemented in the future, in any case, it is better with curvature than without it :D
Title: Re: Corona Curvature Map playground!
Post by: v.p.vlasenko on 2022-10-25, 18:37:17
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)

Up
Title: Re: Corona Curvature Map playground!
Post by: arqrenderz on 2022-10-25, 21:17:48
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)

Up

Up+1
Title: Re: Corona Curvature Map playground!
Post by: philipbonum on 2022-10-27, 13:12:53
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)

Up

Up+1

+1
Title: Re: Corona Curvature Map playground!
Post by: Dionysios.TS on 2022-10-27, 13:14:24
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)

Up

Up+1

+1

+1
Title: Re: Corona Curvature Map playground!
Post by: brr on 2022-10-28, 11:05:47
guys, but still, how about ignoring bump maps? V-Ray has this option

I'm sure this option will be very useful for creating more complex masks.

(https://i.ibb.co/SdVmSby/curvaturemap-ignore-bump-lowr.jpg) (https://ibb.co/D8wMdhW)

Up

Up+1

+1

+1
+1
Title: Re: Corona Curvature Map playground!
Post by: Stefan-L on 2023-01-17, 17:58:59
+1
Title: Re: Corona Curvature Map playground!
Post by: brr on 2023-03-24, 14:10:46
Hello devs and users,

Another important aspect why we definitely need this "ignoring bumps/normals" option is that if I render an object with curvature effects and then want to bake it, usually I need to tweak the strength of the bump/normal maps a little bit to make them look closer to the classic rendering. However, if I change the normal map/bump map strength, I get a completely different distribution, which causes a completely different look. In situations where I have some textures plugged to curvature and powering this effect by output map to get nice paint damages, it is most noticeable.

I hope you will fix this.

Best regards.
Title: Re: Corona Curvature Map playground!
Post by: brr on 2023-03-25, 15:42:05
Hello again,

I apologize if my second post in the same thread is considered flooding. I wanted to divide the issues into separate posts.

In this post, I want to discuss the missing flexibility of CoronaCurvature. It seems that its usage is currently limited.

For example, in my current project, I need to define convex edges and use them as a mask to generate metal damages and rusty effects.
However, when I apply CoronaCurvature, objects with edges near the front face and within the ray directionality radius start to display backedges on the front faces, causing issues.

This behavior is also observed in the official Corona tutorial, as can be seen here:
https://youtu.be/F95JyIaP5kQ?t=56  (https://youtu.be/F95JyIaP5kQ?t=56)
Jake presented a cabinet, and when he increased the maximum distance, inner edges began to pop up on the front faces.

Negative values in the "color spread" field do not solve the issue because we lose many convex edges.

It is also interesting to note that when I attach my geometry parts together, CoronaCurvature generates completely different results.

Please take a look at my attachments:

00.The official tutorial has issues too.jpg - screenshot from Jake's tutorial with the same issue.
01.Curvature-only.jpg - CoronaCurvature "sees" the edges that are behind.
03.Curvature-with-texture-plugged.jpg - the same situation with a texture plugged in.

I have also attached my test scene.

Currently, I have not found any way to solve this behavior.
Maybe someone has had the same situation and can recommend some workarounds?

Best regards
Title: Re: Corona Curvature Map playground!
Post by: Jpjapers on 2023-04-18, 13:37:28
Hello again,

I apologize if my second post in the same thread is considered flooding. I wanted to divide the issues into separate posts.

In this post, I want to discuss the missing flexibility of CoronaCurvature. It seems that its usage is currently limited.

For example, in my current project, I need to define convex edges and use them as a mask to generate metal damages and rusty effects.
However, when I apply CoronaCurvature, objects with edges near the front face and within the ray directionality radius start to display backedges on the front faces, causing issues.

This behavior is also observed in the official Corona tutorial, as can be seen here:
https://youtu.be/F95JyIaP5kQ?t=56  (https://youtu.be/F95JyIaP5kQ?t=56)
Jake presented a cabinet, and when he increased the maximum distance, inner edges began to pop up on the front faces.

Negative values in the "color spread" field do not solve the issue because we lose many convex edges.

It is also interesting to note that when I attach my geometry parts together, CoronaCurvature generates completely different results.

Please take a look at my attachments:

00.The official tutorial has issues too.jpg - screenshot from Jake's tutorial with the same issue.
01.Curvature-only.jpg - CoronaCurvature "sees" the edges that are behind.
03.Curvature-with-texture-plugged.jpg - the same situation with a texture plugged in.

I have also attached my test scene.

Currently, I have not found any way to solve this behavior.
Maybe someone has had the same situation and can recommend some workarounds?

Best regards


Just some quick thoughts on what could maybe provide a temporary fix.

Can this not be resolved by reducing your Max Distance and increasing your colour spread? If the max distance is larger than the gap between sides then i would assume it could have an effect like this.

Theres also the max data channel modifier that can do curvature maps in conjunction with a vertex color map as an alternative to corona. I find that its much slower to work with but could provide a solution to your specific problem.
Title: Re: Corona Curvature Map playground!
Post by: GeorgeK on 2023-05-12, 08:13:44
Hello again,

I apologize if my second post in the same thread is considered flooding. I wanted to divide the issues into separate posts.

In this post, I want to discuss the missing flexibility of CoronaCurvature. It seems that its usage is currently limited.

For example, in my current project, I need to define convex edges and use them as a mask to generate metal damages and rusty effects.
However, when I apply CoronaCurvature, objects with edges near the front face and within the ray directionality radius start to display backedges on the front faces, causing issues.

This behavior is also observed in the official Corona tutorial, as can be seen here:
https://youtu.be/F95JyIaP5kQ?t=56  (https://youtu.be/F95JyIaP5kQ?t=56)
Jake presented a cabinet, and when he increased the maximum distance, inner edges began to pop up on the front faces.

Negative values in the "color spread" field do not solve the issue because we lose many convex edges.

It is also interesting to note that when I attach my geometry parts together, CoronaCurvature generates completely different results.

Please take a look at my attachments:

00.The official tutorial has issues too.jpg - screenshot from Jake's tutorial with the same issue.
01.Curvature-only.jpg - CoronaCurvature "sees" the edges that are behind.
03.Curvature-with-texture-plugged.jpg - the same situation with a texture plugged in.

I have also attached my test scene.

Currently, I have not found any way to solve this behavior.
Maybe someone has had the same situation and can recommend some workarounds?

Best regards

Hi, we will see to it if some further improvements can be introduced. Please stay posted.

(Internal ID=1112977186)
Title: Re: Corona Curvature Map playground!
Post by: brr on 2024-03-01, 21:35:41
Hello Corona-Team,

Are there any potential plans for v12 to fix curvature-related issues?


Best regards
Title: Re: Corona Curvature Map playground!
Post by: maru on 2024-03-08, 17:29:25
Depends what exactly you mean. :)
We have "ignore bump" option in the newest daily: https://forum.corona-renderer.com/index.php?topic=41598.0
Title: Re: Corona Curvature Map playground!
Post by: brr on 2024-03-09, 12:26:36
Depends what exactly you mean. :)
We have "ignore bump" option in the newest daily: https://forum.corona-renderer.com/index.php?topic=41598.0


Hello Maru,

The "Ignore bump" option is a must-have, for sure.
I am also referring to my post at https://forum.corona-renderer.com/index.php?topic=35473.msg222493#msg211123 , where we get not only the "real" edges of the objects, but also unwanted edges such as backside with a curvature map.

Hope you can fix this as well.
Title: Re: Corona Curvature Map playground!
Post by: maru on 2024-03-28, 15:13:28
Sorry for the delay. This is still on the dev team todo, but no promises or specific dates at this time.