Typical decomposition into render elements

[Ondra]

I am redoing the render elements, and I am wondering, how should the TYPICAL decomposition of beauty pass into elements look like - what are the typical elements one separates the scene into? What I am currently planning is this:

diffuse direct + diffuse indirect + reflect + refract + translucency + emission

Do you think some of these should be divided further (for example direct/indirect translucency), or less (for example no separate direct/indirect diffuse)?


This will be just default setup of render elements, but there will be possibility to make custom render elements with custom contribution arrangements.

[mp5gosu]

Lighting + Global Illumination + Reflection + Specular + Refraction + Sub-Surface Scattering + Self Illumination
and full:
Diffuse * (Raw Light + Raw Global Illumination) + Raw Reflection * Reflection Filter + Specular + Raw Refraction * Refraction Filter + Sub-Surface Scattering + Self Illumination

source: http://vfxpedia.com/index.php?title=FAQ/Combining_3D_Passes

[Ondra]

What is the difference between reflection and specular in this case?

[mp5gosu]

Specular is a fake reflection and - of course - not really needed for physical renderers.

[astudio]

How to split direct / indirect lighting in case of hdri?

[pokoy]

I think the initial formula sounds good... but where's the shadow element? It's missing in each formula posted so far.

[Ludvik Koutny]

I think the initial formula sounds good... but where's the shadow element? It's missing in each formula posted so far.

Compositing shadows does not work...  it never did, maybe in scanline, but even there, it caused a hell of a lot of problems. Only compositing that will give you correct result is ADDitive. Shadows can not be composed additively. It is extremely old legacy way of compositing where you did not expect to compose same result as you beauty pass.

[racoonart]

Just want to link this thread for completeness: http://forum.corona-renderer.com/index.php/topic,1858.msg13903.html#msg13903 ("Render Elements reordering")

Basic (as suggested):
diffuse direct + diffuse indirect + reflect + refract + translucency + emission

better:
Diffusecolor + diffuse direct + diffuse indirect + reflect GI + reflectDirect  + translucency + emission
reflect direct is the reflection part coming from direct light sources, already doable by dividing existing REs but would be a fine thing since it somehow feels like speculars (see linked thread above). This one would pretty much correspond to what people should know from other renderers.

all above that (more splitted-up elements) is personal taste imho - like normals and stuff like that.

[Ondra]

How to split direct / indirect lighting in case of hdri?

HDRI in Corona is the same light as all others, so it is direct

[bograt]

I would have to test this to confirm but in the past I think I tried to blend reflect and diffuse in Photoshop using linear dodge (add) and the results seemed inaccurate or incomplete.
It is sometimes very useful to output individual elements or light sources and blend in photoshop, nuke etc. using the add blending mode.
Cheers

Jules

[Ondra]

I would have to test this to confirm but in the past I think I tried to blend reflect and diffuse in Photoshop using linear dodge (add) and the results seemed inaccurate or incomplete.
It is sometimes very useful to output individual elements or light sources and blend in photoshop, nuke etc. using the add blending mode.
Cheers

Jules

that is because you need to add them without gamma and then add new gamma

[astudio]

May be it's not about this topic, but is it possible to get element for special material ID with AA? Just mask. It would help a lot in postproduction. Something like Render Mask script which I used with vray?

[Ondra]

There are plenty of mask elements, so it can be done already

[loocas]

Don't forget that RAW passes are actually very important here because in most cases you will be utilizing the actual BEAUTY pass and dividing it into secondary passes. Otherwise your AA won't work, unfortunately.

[andreupuig]

Is possible an element wich include direct lighting for every light/group of lights? (yes, something like vrayLightSelect element) It could be very useful for partially re-light the image without re-render everything.