CoronaDecals playground!

[Aram Avetisyan]

Corona Renderer 8 Oct-12 daily build comes with new CoronaDecals!
https://www.dropbox.com/s/26uk33cs6yufcur/corona-8-3dsmax-daily-2021-10-12.exe?dl=1
They can be found in Create > Geometry > Corona subtype menu.
You create CoronaDecal, assign a material with or without opacity to it and it will project on all surfaces intersecting its bounding-box.
There is a quickstart scene attached (Max 2019).
Give it a go and share your results here!

[aaouviz]

Not bad. Just gave it a shot. A nice quick way to avoid CoronaLayeredMaterial I guess...

One constraint I see is that when I gave it displacement (so it's popping out from the base surface) the base materials displacement is lost. In the same way as only 1 displacement is supported on Layered Material. I'm sure you're well aware of this.

Hope I can put it to good use...!

[romullus]

One constraint I see is that when I gave it displacement (so it's popping out from the base surface) the base materials displacement is lost. In the same way as only 1 displacement is supported on Layered Material. I'm sure you're well aware of this.

In many cases this is desirable effect (you don't want that asphalt displacement would mix with manhole displacement, right?). An request for option to override some maps and at the same time retain others, is already requested and logged by the team for consideration.

[marchik]

Yep, I tested everything well again, the fact that the displacements does not mix together removes half of the use cases, I am a little disappointed with that.

A logical option would be when the base layer displacement is ignored only at the place where the decal is overlaid, or giving some options like Only A, Only B, A+B

[aaouviz]

Yep, I tested everything well again, the fact that the displacements does not mix together removes half of the use cases, I am a little disappointed with that.

A logical option would be when the base layer displacement is ignored only at the place where the decal is overlaid, or giving some options like Only A, Only B, A+B

\

+1

[romullus]

Yep, I tested everything well again, the fact that the displacements does not mix together removes half of the use cases, I am a little disappointed with that.

A logical option would be when the base layer displacement is ignored only at the place where the decal is overlaid, or giving some options like Only A, Only B, A+B

Wait, i was under impression that that's exactly how decals are working now, i.e. you can have displacement from both, target and projection surfaces, but it looks i was wrong and indeed you can only have displacement either from one or another, but not from both at the same time. That's a huge disappoitment :[ I hope it can be improved before release, otherwise i too find decals' usefulness pretty limited.

[Aram Avetisyan]

The displacement issue is known, same kind of problem is with normals and their mixing/mapping, some weird stuff happens with LightMtl as well and there are some known viewport preview "bugs".
Nevertheless, we think that there is enough implementation of decals for now to start playing around with them.
Feel free to share your thoughts on use cases, features that you would like to have with decals here.

Regards,
Aram

[maru]

Did you... Did you just slap a new name on the distance texture mapping for decals that people have already been doing, there are even tutorials online about it, and call it a day?

No, this is a completely new feature, unrelated to Corona Distance. The underlying technical solution is very different.

One of the MAIN things about proper decals is that they need to have displacement and by the looks of it you didn't even think about that.

Can you please explain what exactly you mean by that?
Projecting a decal onto a surface with displacement is supported.
Projecting a decal with its own displacement is supported too.

Again half a year for pretty much nothing can't wait for the new tone mapping in 2028 and proper working converter in 2038.

Let me quote: "Wow absolutely nothing to say here."

Also, please remember that this feature is included in a daily build of Corona, which means that:
- it is still a work in progress
- we are currently collecting user feedback about it to make it better

If you have a specific vision how a perfect decal feature would work for you, please do share it so that we can improve.

[Jvincentrs4]

I think over all it is a great start, I do see what people mean about the overriding displacement.  Here is a quick example nothing fancy a ground from megascans and a decal from megascans.

But this is also based on ones thinking of Decal. If we are thinking of this like a sticker on a surface then I would say it is very close to working as it should. Example you have a sticker you place that sticker on you window that
has dirt on it the sticker takes the displacement of the dirt on the window.

Now if the hope and I think what some people are thinking is this would be like two geometries as in example three.

Test_01 I have both displacements on and it does project to the ground but it removes the displacement from the soil texture
Test_02 Removed the displacement from the cloth and the texture wraps to the dirt displacement (Sticker or Decal) 
Test_03 Made geo from the cloth texture and now you have a interaction like you would expect in this case or close to it.


I don't think what has been done is useless just for specific conditions and still Rad. Lets be positive progression always takes time.

Sorry to add one thing I there should be an addition to map around something. Say you are doing a decal that wraps 360 around a cylinder there does not seem to be support for this
currently maybe some work around but would be nice to have the option to have different decal types. 

Jimmy

[Ondra]

if I understand it right as "the displacement from decal should be added on top of the original displacement, not replace it", that is very easy to do, and can be added as a mode

[Jvincentrs4]

Ondra

I think that would be cool. I think then Maybe it would be more like people have in mind.

Great work.

[LorenzoS]

Hi,
Cdecals works as proiection as i can see, a checbox for proiection/normal_to_surfaxes or somting similar i think it will be usefull.

[Jvincentrs4]

Great Example this is what i was talking about having based on normals would be great. Any Curved surface gets very odd.

[romullus]

if I understand it right as "the displacement from decal should be added on top of the original displacement, not replace it", that is very easy to do, and can be added as a mode

I think there's too much ambiguity in the words "on top" and "replace", so i draw some picture. What i, and i think many others, expected from decals, that it could work like in a, b and c examples. a - only decal is mapped, b - only target is mapped and c - both are mapped (i'm talking only about displacement here). Currently we have a and b, but not c.

I think some people also asked for d - where displacements are mathematically added through some blend modes. This can be useful in some cases, but i think it's not crucial to have it right now.

[Ondra]

if I understand it right as "the displacement from decal should be added on top of the original displacement, not replace it", that is very easy to do, and can be added as a mode

I think there's too much ambiguity in the words "on top" and "replace", so i draw some picture. What i, and i think many others, expected from decals, that it could work like in a, b and c examples. a - only decal is mapped, b - only target is mapped and c - both are mapped (i'm talking only about displacement here). Currently we have a and b, but not c.

I think some people also asked for d - where displacements are mathematically added through some blend modes. This can be useful in some cases, but i think it's not crucial to have it right now.

C is how it was always supposed to look, if it does not, that means a bug got in at some point and we will fix it.
D would still be doable if requested