Nesting Multi/Sub-Object materials is not supported in corona Layer material

[Digital Esthetics]

is there any planned fix for this? I have a car with multi sub material on and would like to add an overall dirt effect over it. now I have to go in to every material and do layer material for each material which takes so much time.
Vray have this so why can't corona have this?

[Tom]

Hi,

Very interesting topic, thanks for posting.
If you have a VRay licence, and since you say VRay handles it, you can convert the VRay material into Corona. It's not ideal as you will still have to manually tweak every material one by one, but at least it should be a bit less time consuming.

The only workaround I can think of is creating dirt using decals.

[pokoy]

I wonder if you can use a Blend material for this.

[Digital Esthetics]

Hi. I dont have Vray and thats not the issue. the issue is that we cant have a multi sub material nested in Corona Layer material. and I don't think blend material works either. but I will check

[Digital Esthetics]

I wonder if you can use a Blend material for this.

Nope. also not supported for some reason.

[Digital Esthetics]

Hi,

Very interesting topic, thanks for posting.
If you have a VRay licence, and since you say VRay handles it, you can convert the VRay material into Corona. It's not ideal as you will still have to manually tweak every material one by one, but at least it should be a bit less time consuming.

The only workaround I can think of is creating dirt using decals.

Hi, so I just followed a tut on youtube and there he can do it with Vray. and I don't see why we corona users shouldn't.

[Avi]

This is not possible at the moment but please log your feature request on our Ideas Portal: https://chaoscorona.ideas.aha.io/
You will need to pick "Add a new idea" and describe your feature request in detail.

For more information, please see:
Corona for 3ds Max - https://forum.corona-renderer.com/index.php?topic=43389.0

[zaar]

This was the first thing that put me off when I had to move to Corona. What if you have for example a car that has a very complex MultiSub and you just want to put a layer of dust or dirt on top of it. IMPOSSIBLE!
I would definitely vote for this idea!

Corona Blend Material also has a weakness in that it doesn't allow for transparancy in the materials themselves, only the mask. I know this is on purpose and some people consider it a feature and not a flaw. I've learned to live with it, and in fact the behavior is usefull at times.
I have a suspicion that there is a strange historical reason for why it works like this. Correct me if I'm wrong! I've many times heard people say, both IRL and online, that Corona Layered Material is better than V-Ray Blend Material because V-ray Blend is not physically correct and that "you cannot add transparent things on top off eachother". Yes, V-ray Layered material has a crazy legacy (?) mode called "Additive (shellac) mode" - that you don't have to use. And if you don't use it you can make concrete and put a glass material on top of it without any masking, kind of like how clearcoat works without breaking physics. That's how I remember it anyway. And now that I think of it, the naming is kind of backwards. Corona, that only blends/mixes is called layered! and in V-ray that can acctually treat them as layers, it's called v-ray blend material.

Proposition:

Scrap the old materials and transform:

V-ray Blend -> Chaos Layered Material
Corona Layered Material -> Chaos Blend Material
And have them both be cross compatible.

Confusing! YES! Many meetings for developers? YES!

So maybe just add a checkbox to toggle layered/blend mode?


Sorry if this was a detour, I still think that it of course it should support multi/sub!

[zaar]

GO VOTE!!!
https://chaoscorona.ideas.aha.io/ideas/CMAX-I-164

[TomG]

Remember that people can't vote until an Idea moves out of New into Pending (or some other status). Before then, it just comes up as not found :)

[TomG]

And it is in Pending now (though this does not always happen as fast, can even be a few days or a week before things on Aha get reviewed and moved out of New - if you are the person who posted the idea, it should notify you of the status change, so you know to promote it on the forum only after that, to save user frustration :) )

[zaar]

Great to see that it's pending.

I was thinking that this might be complicated due to some internal logic in the way Corona handles materials, and since it's been this since forever and never changed. But then I got the idea to try to use a Corona Decal to do the same thing, just put a wire material over the object using Corona Wire in the opacity slot of the decal material. Works perfectly! Looks like there's really technical limit that doesn't allow for this to happen.

EDIT: It's even possible to put a layered material on the decal!

[Tom]

Indeed, the decal works pretty well.
Obviously it's still hard to control where does the effect appear exactly, you may want to exclude some parts of the car, the windscreen for example doesn't work very well here, probably because of the AO map, but it's fast and pretty easy to do.

Not sure why using a CoronaWire map?

[zaar]

haha, wire map was to showcase the wireframe of something that I thought I had modelled very well without tris or n-gons ;)

If the car is one mesh and multi-sub and you want to exclude the dirt from certain parts, you can combine a Corona Multi Map (set to face material ID only) with your other splatter masks using the multi map on a multiply layer. Set the same amount of colors as your multi-sub and make them black or white depending on what material ID you want the mud.

What an ugly hack, but I'm still kind of enthusiastic about the possibility.

EDIT: Don't forget to vote: https://chaoscorona.ideas.aha.io/ideas/CMAX-I-164