Will the gbuffers have good antialiasing in the future?

[panthon]

We use them a lot via RPF and it would be specially good to AA the selection gbuffers, as renderid, nodeid, materialid, even at the expense of longer rendertimes. I don´t really know if it´s possible or if it´s already implemented in internal betas. I used to read that was difficult in the past but i would like to know about current situation of this issue.

Thanks.

[vlado]

This is not possible for all channels. For example, the render ID channel is an integer channel. You can't antialias that - you'd need floating-point numbers.

However, some of the Render Elements in newer builds (zbuf, normals, velocity) allow you to choose between filtered and unfiltered output.

Best regards,
Vlado

[Dynedain]

Isn't this what the coverage channel is supposed to solve?

[DaForce]

how exactly does one use the coverage channel in combustion anyway?
I admit my time using combustion is nothing to gab about, but still i cant seem to work it out.

[Dynedain]

I'm not exactly sure, but most of the RPF 3D operations recommend having the coverage gbuffer present for best effect. I believe it basically operates as a mask to mark the edges of objects and apply bluring on the gbuffer effects

[panthon]

Vlado wrote: For example, the render ID channel is an integer channel. You can't antialias that - you'd need floating-point numbers.


Ok, maybe it´s not possible to antialias this particular channel...Could vray fake this channel by assigning random colors to objects and embed this information back to rpf´s node render id channel?

The information u get from node renderid channels looks this way:



It looks like a simple render with random, cartoonlike colors, but it would greatly benefit from AA, which would be no problem because it would be rendered by vray using the AA settings.

GRanted, u can render it anyway using a random material script and then in combustion, use a gbuffer builder to add this layer to the image layer, but it´s a real hassle...The point is, if i can do it manually, can vray do it automatically?

The same goes to Object ID and material ID, but it would be trickier coz u need to look at the number they have been assigned and choose a color, and only a color which will not be used again, to represent that particular id.

Just ideas, though.

[dimo]

This is not how the object id in the rpf is supposed to work. If you want to code the objects by color you can only save 3 objects with antialiasing. (One for each color channel). This is what we do. Assigning a self-illuminated material with Full red (blue/green) to the object. By using the matte options from vray. You can save 4 colorcoded object ids with antialiasing into an RGBA image.

What you see in the rpf object channel is only a colored representation of the data. Using antialising would mean that e.g. the purple object id would mean half red and half blue!

Best regards,

[panthon]

This is not how the object id in the rpf is supposed to work. If you want to code the objects by color you can only save 3 objects with antialiasing. (One for each color channel). This is what we do. Assigning a self-illuminated material with Full red (blue/green) to the object. By using the matte options from vray. You can save 4 colorcoded object ids with antialiasing into an RGBA image.

What you see in the rpf object channel is only a colored representation of the data. Using antialising would mean that e.g. the purple object id would mean half red and half blue!

Best regards,

Thanks for your answer, dimo!

Ok, I understand it now. So there isn´t any human way on earth to get proper masks from objects in a 3d render to use in post? If gbuffers is not the way to go, is there any other?. 3 or 4 objects are not enough for most of the tasks...
How do the big film companies out there overcome this issue with maya-renderman or whatever?

P.S:However, i´ll try your way dimo just in case i need any particular object mask to be antialiased

[vlado]

I believe psd manager can output each object into a separate layer in the resulting .psd file. It uses the coverage channel to preserve the object antialiasing.

Best regards,
Vlado

[panthon]

I believe psd manager can output each object into a separate layer in the resulting .psd file. It uses the coverage channel to preserve the object antialiasing.

Best regards,
Vlado

Thanks, Vlado. I´ll give it a try.

[panthon]

Well, I´ve found out that including coverage channel in the rpf will give u a correct object selection in combustion, with no jagged edges, but it will only work with Object Id selection, not Material selection or Gbuffer extract. Node render id selection is not supported by combustion at the time.

[Dynedain]

See? I told you using the coverage would help

Somewhere buried in the Combustion help file (I think I found it by searching for 3D Glow) there is a chart showing what rpf gbuffers are required and recommended for each of the 3D Post operators.

I wish this existed somewhere else so I could point a link

[Da_elf]

if anyone does find a COMPLETE document of all channels in use and how the need to be combined that would be awsome. velocity channel, object ID, z-buffer etc. so basically we can see how to composite a scene with different GI and lighting and reflection channels that would also have in DOF and motion blur. a motion blured DOF object would be interesing to see.

[DaForce]

Dynedain:
You rang???
http://www.apex.net.au/~daforce/vray...stion4_rpf.pdf

[jacksc02]

good boy daforce