Glass from Studio to Blender via Diffemorphic??

brainmuffin

I've been having the hardest time correctly getting glass (in say a Window) to be transparent in Blender using Cycles. Anyone have a good recipe to follow?

Krys Kryngle

There is a glass bsdf node in blender, but I think most people mix gloss and transparent to get the effect they want. 

The easiest way is to head over to blendswap and search for 'glass' or 'glass shader'.  There are a bunch of different models with materials depending on what color and type of glass you want.

Another option, maybe even easier, is to add the free version of Blenderkit.  They have about 50 different glass shaders in the free section.  That is just drag and drop, wicked easy after you sign up and install.

Padone

Diffeo should correctly convert glass from iray to cycles. That is, if it works in iray then it should work the same in cycles. If not, please provide a simple test scene so we can look at it. If you are referring to caustic effects then cycles is just not good at that, there's nothing we can do.

Also be sure to select the BSDF option for materials that gives the best conversion.

SDev

A nice glass caustics shader workaround for 2.8+ https://www.creativeshrimp.com/uber-glass-shader-blender.html

Padone

@SDev Using a "transparent color ramp" for shadow rays is of course a viable way to fake caustics. But this has nothing to do with real caustics. I mean, the faked caustics are just a nice "paint" with nothing to do with PBR.

 

edit. For anyone interested below a common setup for fake caustics, that's also used in the video above. Basically the dot product is used to trace the color ramp from the outside to the inside of the shadow area, so you can paint whatever you want on the shadow and make it seems a caustic effect.

https://bitbucket.org/Diffeomorphic/import_daz/issues/400

brainmuffin

Padone said:

Diffeo should correctly convert glass from iray to cycles. That is, if it works in iray then it should work the same in cycles. If not, please provide a simple test scene so we can look at it. If you are referring to caustic effects then cycles is just not good at that, there's nothing we can do.

Also be sure to select the BSDF option for materials that gives the best conversion.

The model in question is Solaris Control Cabin (https://www.daz3d.com/solaris-control-cabin). I'll run and post a render from Iray and one from Blender. The glass is too reflective and not transparent.

brainmuffin

The left image is a Render from Studio using Iray. The right image is a converted to Blender via Diffeo using cycles.

 

SDev

Padone said:

@SDev Using a "transparent color ramp" for shadow rays is of course a viable way to fake caustics. But this has nothing to do with real caustics. I mean, the faked caustics are just a nice "paint" with nothing to do with PBR.

 

edit. For anyone interested below a common setup for fake caustics, that's also used in the video above. Basically the dot product is used to trace the color ramp from the outside to the inside of the shadow area, so you can paint whatever you want on the shadow and make it seems a caustic effect.

https://bitbucket.org/Diffeomorphic/import_daz/issues/400

That's why I wrote 'workaround' Alessandro.:)

TheMysteryIsThePoint

@brainmuffin

I think you'd find The Cycles Encyclopedia both extremely useful and extremely interesting. For something like glass, you could probably just do it from scratch and end up with something you like better, anyway.

Padone

@brainmuffin

1. Be sure to use iray materials (uber shader) in daz studio. Then diffeo has some support for 3Delight but it's not so good.
2. Use cycles with the bsdf conversion when importing in blender. That's the best option for material conversion.
3. The environment hdri has to be the same to get the same results, be sure to set "draw dome = on" in daz studio for the hdri to be imported in blender.
4. Be sure to get enough render quality in cycles. Then diffeo will set the minimum requirements as default, or give warnings on import if you change that. If you have any doubts then set cycles to the maximum quality that's the "full global illumination" preset.

If the conditions above are respected, that's what to do for a high quality material conversion, then here I get the same results in daz studio and blender, apart tone mapping. Below first iray then cycles, with the default iray hdri.