What I typically end up doing is creating a normal c4d material, place that opacity map in the diffuse slot, apply it to the material and then map it to the object that way - because I can see it in the viewport.

Sure, you can use the final beauty IR but that only works on simpler objects and in simpler scenes. You used an opacity mask for the label material but you have _no idea_ how it maps onto the object. So take the layered material from the above - you have a base material and a label material on top. I don't think there is a renderer out there that doesn't have a feature that lets you preview the maps you are working on either in the viewport or in the IR. Now, one could use a Corona layered material but that leads right into my other point about. Sometimes it appears to be working though. Sometimes it completely breaks material stacking in the object manager and you get a weird result out of it.

Sure, you can apply a Corona bitmap to the opacity slot of that top material but it is again, unreliable. I went from renders taking 30 seconds to taking 1 hour. Stacking itself works fine but it tanks performance ~10x. You got a base material and then a material with an opacity map on top. So, typically you can stack materials in the object manager so that you can do things like decals and labels. Still, it's buggy and wonky yet is one of the most crucial things a renderer can do. Yep, I know we need to use Corona Bitmaps to increase the performance of materials with opacity maps. What is even funkier is that the project shader is currently bugged so besides using a Layer -> Transform to scale maps, there virtually isn't a way to do this properly with Corona which makes it really hard to use for. All of the sudden, you need to go in each and every map in all of your materials.

Further complicating things, you perhaps change the mapping and. Imagine having a lot of maps and each was being driven by its own project shader - you scale one map you need and it works fine but scale multiple maps and you need to go in each one manually. All of the other renderers have resolved this ages ago because you can't rely on the projector shader alone - It works locally and so each map you'd want to change you'd need to change independently.

We currently have super limited ways of doing UVW transforms and I totally think this is a Maxon oversight (resolved in R20 with the UVW node) but it is what it is. So to that end, I'll just throw a couple of things that I think Corona should do better and other renderers typically do better :) Heh, I really don't want to turn this thread into a 'renderer vs renderer' thread but I would like to share my opinion as well.

Vdb octane render for cinema 4d