little question plz (multi channel rendering)

[luckysniper]

hi all,
i use 3ds max 2009, i need to render to EXR file format with more Extra Channels like
diffuse, reflection, refraction,... and so on
how can i get this option

can anyone help me

thanks alot and waiting for answer

[RichardAnnema]

Looks like the original question never got picked up on. In 3ds Max 2011 and in 3ds Max 2010 with the Connection Extension(1) (subscription pack) installed, it should be as simple as using a renderer which supports render elements. These render elements can then be piped out to the OpenEXR format as new data channels.
This will not work for renderers that do not support Render Elements - including Brazil - and the older OpenEXR plugin included with 3ds Max does not accept Render Elements as data channels either.
As an alternative for older versions of 3ds Max where the new OpenEXR plugin is not available, you may wish to consider cebas's commercial PSD (Photoshop) output plugin.

1) http://usa.autodesk.com/adsk/servlet...12&id=13606852
2) http://www.cebasstation.com/index.ph...38&feature=708

[Gavin Greenwalt]

Wouldn't it be possible to output Reflection, Refraction and Diffuse as "G-Buffers"? Brazil already outputs normals etc. So there must be a code path to output that data.

Adding XYZ to that would also be dandy.

[RichardAnnema]

Originally Posted by Gavin Greenwalt

Wouldn't it be possible to output Reflection, Refraction and Diffuse as "G-Buffers"?

'fraid not

Originally Posted by Gavin Greenwalt

Brazil already outputs normals etc. So there must be a code path to output that data.

Yes - but that data and that data only. These are the pre-defined buffers from the 3ds Max API and you are limited to these and only these as far as the g-buffers go. RLA and later RPF, OpenEXR, etc. can all write these and -only- these out. Render Elements are far more flexible, allowing any arbitrary new element to be added. On the flip side, you can't store these in RLA/RPF 'as is' (you can write out individual elements, of course).

One buffer we -have- added - the ray depth channel - is not a g-buffer.. and there's no bitmap i/o plugin that will write it out.

[Gavin Greenwalt]

What if you hijacked a few of them?

Normal -> Reflection
Color -> Diffuse
Velocity -> Refraction

We always render those in scanline so that they're faster anyway.

[RichardAnnema]

I rather think that by the time we'd get around to splitting out such things at the same time as the main render - which I realize is your main concern - we would just use render elements instead of very h(ij)acky solutions

[Gavin Greenwalt]

I didn't know if the problem was creating AOVs for the shaders or the actual render element interface being difficult to accommodate.

I was always under the impression it was the render elements themselves, not the rendering of separate passes that was problematic.

That being said. If you replaced something useless like Unclamped color with pXYZ I would be much obliged.

[RichardAnnema]

Unclamped is still used by some render effects that don't work with 32bit float buffers.. among other.

I'll presume one of the developers actually knows what a pXYZ buffer is - but if it's related at all to XYZ colorspace, then I'm not sure what good that would do as all calculations are in yea olde RGB.

[Gavin Greenwalt]

pXYZ: Position XYZ.

I was thinking you could provide a set of drop downs in a render sub-dialog which lets you choose a GBuffer of your own to use instead of any of the presets.

I would be happy to sacrifice render effects. But it sounds like the unclamped color isn't in float. That would be problematic I guess for a pXYZ pass since you would need floating point precision.

[RichardAnnema]

Originally Posted by Gavin Greenwalt

pXYZ: Position XYZ.

then... FOV + Z-Buffer = pXYZ ?

Originally Posted by Gavin Greenwalt

I was thinking you could provide a set of drop downs in a render sub-dialog which lets you choose a GBuffer of your own to use instead of any of the presets.

'fraid not

Originally Posted by Gavin Greenwalt

I would be happy to sacrifice render effects. But it sounds like the unclamped color isn't in float.

Correct. The Unclamped Colors G-Buffer uses the RGBe buffer type. This is the same as the Radiance HDR format - i.e. 8bpc for the RGB with a shared exponent.