0
$\begingroup$

I made a test scene with a windowframe with glass, glass without a frame and a solid cube. Sun is the main light source with a little bit of HDRI lighting in the world settings. In cycles the tinted glass casts a colored shadow. In Eevee the tinted glas does not cast a colored shadow.

Next, you can see that in the Eevee image the cube casts the same shadow as the left glas plane. In Eevee I cannot set soft shadows for the glass in the light settings or the render because that also blurs the shadow of the windowframe. So I can only do this in the material tab (or nodes) and that does not seem to work; glass shadows are either opaque or completely transparent. I used Princ BSDF and Transp BSDF with a mixed shader.

I have 2 questions:

  1. Is it possible in Eevee to make tinted glass cast a colored shadow just like in cycles?

  2. How do I set the glass shadow soft (but transparent) while keeping the window frame shadow opaque in Eevee?

Cycles:

Cycles

Eevee:

Eevee

$\endgroup$
  • $\begingroup$ For #2 you want an area light. An HDRI background does wonders to realism. $\endgroup$ – John Dvorak Dec 18 '18 at 20:38
  • $\begingroup$ Tried that in different configs with Eevee, but couldn't get transparent soft shadows, The shadows are then either opaque or very diffuse/blurry. Best results I had sofar in Eevee is a combi of sunlight with very low strenght HDR world background (0.05). That is what you see in the Eevee image. There is however no difference between the shadow of the solid cube and the left glass. $\endgroup$ – Taaske Prins Dec 19 '18 at 11:10
  • $\begingroup$ Recommended reading: Cycles vs Eevee, 15 limitations on real time rendering $\endgroup$ – cegaton Jun 2 at 20:40
1
$\begingroup$

Pretty easy faking colored caustics in cycles mixing a transparent shader and a Glass/Principled Shader with these nodes. enter image description here

However that trick does not work in EEVEE enter image description here

You could create it by using a color ramp on the surface material or a projection of color on the shadow if it's a still image it's a crude hack that changes the surface instead. like this: enter image description here This trick maps the shadow area to a different color.

$\endgroup$
  • 1
    $\begingroup$ Thanks for your contribution. Please be aware that answers are moderated and while this attempts to answer the question, there is very little expanation to go with it. Please use the edit function to provide additional information. $\endgroup$ – Moog Oct 20 at 8:56
  • $\begingroup$ ..Agreed. In principle, a really nice answer with interesting methods. Just a word or two explaining how they work would be a great help $\endgroup$ – Robin Betts Oct 26 at 19:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.