Legacy Iray versus PBR Iray

bradassociates

I try and research topics before I post here, but come here when I can't find the information.  Still somewhat new to Daz, I've been noticing that some products contain two different Iray presets in the Materials folder, one is Legacy Iray and the other is PBR Iray.  One such product is Tate for G8.1M:

https://www.daz3d.com/tate-hd-for-genesis-81-male-and-fred-81

SickleYield does a good job discussing Iray surfaces here:

https://www.deviantart.com/sickleyield/journal/Iray-Surfaces-And-What-They-Mean-519346747

However, I'm still confused as to which of the two Iray mats I should use, and when to use them.  I gather that PBR is the more "standard" shader for Daz Iray renders, but takes longer.   I understand Legacy is quicker, but may not render with the same quality in the skins and shaders.  But I'm not sure about that.

Because each of my renders take a very long time to create, I want the best quality in the final render.  For a neophyte in Iray shaders like me, can someone dumb it down so that I'll be able to make the best decision?

Thank you in advance.

 

Richard Haseltine

The Legacy is for a very old version of Ds (4.8.x.x I think) - there was a chnage in the way some shader properties (related to SSS as I recall) behaved in 4.9 so for a while content came with a legacy version for 4.8 and a palin version for 4.9+. You almost certainly want the non-Legacy version.

margrave

Daz3D introduced an updated skin shader alongside Genesis 8.1, which they named the PBR Skin shader.

It's a misleading name, because all of Iray uses physically-based rendering.

Now PAs are advertising their 8.1 products as having "PBR" shaders, confusing people.

The "legacy" Uber shader (which is a PBR shader) and the "PBR Skin" shader have different set-ups in the Shader Mixer, so they're not interchangeable. I presume the PBRSkin shader has additional maps that take advantage of its extra functionality.

Hylas

Richard Haseltine said:

The Legacy is for a very old version of Ds (4.8.x.x I think) - there was a chnage in the way some shader properties (related to SSS as I recall) behaved in 4.9 so for a while content came with a legacy version for 4.8 and a palin version for 4.9+. You almost certainly want the non-Legacy version.

This is true for some Genesis 3 characters. I notice how most (all?) G3 core characters also have a "legacy" setting that doesn´t look good on the current version of IRAY.

However with these more recent characters I think "legacy" means something else. I don´t have Tate but I do have Rocco by the same creators. There "legacy" means IRAY Uber skin (aka what we have been using since late Genesis 2), as opposed to PBR skin (aka the new shader introduced with G8.1.)

With Rocco I see basically no difference between legacy and PBR. The latter might look more realistic in close-up´s but is probably more resource heavy because it uses additional maps.

I´m no expert so I could be wrong about all of this, but that´s the impression I´m getting so far.

Cenobite

PBR isn't always the best, is faster but is highly unstable tends to crash the platform with heavy scenes. The light is also washed out somewhat in PBR filament mode, Iray is the best render when you get the lighting right.

margrave

Cenobite said:

PBR isn't always the best, is faster but is highly unstable tends to crash the platform with heavy scenes. The light is also washed out somewhat in PBR filament mode, Iray is the best render when you get the lighting right.

PBR is neither the best nor the worst, it's literally the only option for Iray and Filament.

Handspan Studios

Yes, "PBR skin shader" has more map types, you can use AO (Ambient Occlusion) and micro Skin Detail in what is called the PBR skin. Some things are no longer there that were in legacy, like some of the options for top coat. If you want to add metal looks or glitter flakes, heavy makeups then legacy is better. If you want the most realistic skin, mostly PBR skin versions are better.