[REQ] Object/material masked rendering

[StompinTom]

Hello!

Something that would be very useful for re-rendering and changing things, and especially for compositing, would be an option to only render a specific object/group or material, much like Region Rendering works now. It wouldn't be a hack, it would just mask out the specified material or object and blast it with samples so that you can get a much faster rendering for separate parts of your scene.

Already I end up composing the final image with separately rendered light layers, which ensures that I can cook the noisy layers for longer if need be. Re-rendering tricky materials sucks, though, because you have to re-render the whole scene right now...

Thoughts?

[CTZn]

it would just [do anything I want] and blast it with samples

Alas, I realised over time that it doesn't work this way StompinTom

No seriously, if there's a way I'm seconding your request Is the idea beneath to have rendering (objects) layers ? Or a mask material with an user defined alpha ? I don't understand how you are relating this to region rendering but that's probably not important ?

PS: I'm not saying that a mask material is even possible.

[StompinTom]

it would just [do anything I want] and blast it with samples

Alas, I realised over time that it doesn't work this way StompinTom

No seriously, if there's a way I'm seconding your request Is the idea beneath to have rendering (objects) layers ? Or a mask material with an user defined alpha ? I don't understand how you are relating this to region rendering but that's probably not important ?

PS: I'm not saying that a mask material is even possible.

I hope I'm not going about this naively as you suggest...

Region rendering takes a rectangular cutout of the image and renders only that, correct? The rest of the image is pretty well ignored, as far as the image plane goes (black). So what I'm suggesting is region rendering, not defined by a rectangle, but by an arbitrary black and white mask, for example using the Object Index in Blender or a kind of Material ID tag.

It would simply be a way of re-rendering select parts of your image without having to waste time on the whole image. For example, if I need to change a particular material in a scene, and I don't care about the effect this would have on other reflections/refractions in the scene, I could re-render only the pixels that depict that material in the image far more quickly than re-rendering the whole image.

[CTZn]

it would just [do anything I want] and blast it with samples

Alas, I realised over time that it doesn't work this way StompinTom

I hope I'm not going about this naively as you suggest...

At least that's what I'm fearing, given than many things in Indigo are outerly more complex than we tend to know from other rendering methods. I'm sorry if I sounded arrogant Tom, but if that was the case I was necessarily including myself into the mass of the wonderers.

What I don't know is wether it would save ressources, but if it only saves time your request would still be a good take, I'm with you

[Zom-B]

such masked rendering could be quite useful for PostPro, to tweak special areas of a image...
But regarding this I have to say that I'm quite happy rendering such matte ID channels out of C4D and using them.
Even the C4D Alpha channel now is very well usable since through the new fastbox filter the image seems to be shifted 1/2 pixel... a "correction" that works out well in my workflow.

Ergo: for me I would like to see other features be integrated (or fixed) first, but the region rendering thing is something to stick with!

[StompinTom]

CTZn: No worries!

Zom-B: I use alpha, z-depth and object index maps from Blender, however sometimes, for example, the client would request a particular material to be changed. In that case, it would be faster to only render the areas of the image with that material.

Basically, what I'm trying to say is: custom Region Rendering shapes would be cool! Down with rectangles...

[neo0.]

Sorry, as I know very little about the subject, but doesn't clip mapping do something similar? I don't know, this sounds like it would be very useful.

[Borgleader]

Sorry, as I know very little about the subject, but doesn't clip mapping do something similar? I don't know, this sounds like it would be very useful.

http://www.torquepowered.com/community/blogs/view/13035
No I dont think clip mapping is similar to what Tom is requesting.

If I understand him properly what he's asking for is the ability to tell Indigo which objects to "concentrate" on so they will render faster than the rest of the scene. By doing so, your render would be black for the rest of the scene (because the rest of the scene has not been sampled) and only the object(s) you choose will be rendered.

Clip mapping is by the looks of that article a totally different subject and seems to be used mostly in video games in order to cope with the low memory constraints of the GPU.

[neo0.]

Ah, well that's different. What I have been trying to figure out how to do is to tell indigo to render some parts of the material, as if it was painted on (over another material.)

[zeitmeister]

+1 for object masks!