VOPs & BSDFs

[DaJuice]

Hi everyone,

Okay this is something that has been vexing me a little (pun maybe intended). How many of the available BSDF functions are represented in VOPs? I've been reading the help and chasing down old threads trying to learn more, but things are still a bit muddled for me. Looking at the code generated by some of the VOP nodes, the usage seems clear enough. For example: it looks like Trace uses bsdf specular() and also cone() if you do glossy reflections, and with Lambert you got your bsdf diffuse(). But then I take a look at what you get out of the Lighting Model VOP or the Specular VOP, and I see things like vop_lighting_bsdf(), and vop_specular_bsdf(), which aren't mentioned in the help. That kind of confuses things a little, I'm guessing these are like wrappers/supersets of the other functions...?

Okay, lets say I'm doing a PBR render: If my shader consists solely of a Specular VOP, and I leave it at the default "Vex Specular", is my shader actually going to be calling the bsdf blinn() function (and likewise "Phong" -> bsdf phong())? What about bsdf phonglobe(), can it be accessed through VOPs? Maybe it would be better to give the BSDF stuff its own set of nodes rather then tucking it into the existing VOPs?

On a related note, I'm trying to figure out a weird PBR issue with reflections of area light sources. I'm seeing reflections that are orders of magnitude more intense than the actual lights. You can see it in the reflections in this render. Has anyone encountered this?

Cheers, and also Happy New Yeaaar!

PBRcornell.hip.zip

[stevenong]

Hey DaJuice,

There's a similar thread over at the SESI forum.

Perhaps you want to continue the reflection intensity discussion over there?

Cheers!

steven

[DaJuice]

Heya Steven, good idea. I've read that thread before, how'd I forget...

Thanks