Trying to wrap my mind around this - Please Help

So if you look here at this image

The moon in this HDR - THe light from this moon knows how to go through this mica shade.
2QuestionWhyDoesMoonlightSHineTHrough.blend (4.3 MB)
So this file - blend file - is from 293.2
And here is what baffles me:

When I put a point light inside of this lamp shade -(below:})

THis light can not make it through the shade - yet the moonlight from the world HDR has no problem making it through the shade. SO how do I make my point light have the same quality as the world moonlight that is give it the magical ability to go through my shade ?

see that, nope it aint gonna go through.
I understand that I can change settings and the light will somewhat go through it seams the way the moon shines through it, that a look I can’t seem to mimic.

Had a look at your file…

The first question … why does the HDRI shine through… actually, it’s not. In eevee, HDRI’s don’t have shadows, and while the HDRI is mostly nearly black, there are enough little points of light dotted all over the sky-sphere that it lights the shade reasnoably evenly.

The second question - why isn’t transluceny working? … well, it is working in cycles! I think the problem is your lampshade is actually two surfaces - an inside and an outside. … at least I thought that was it, but maybe principled in eevee isn’t doing translusency.

On this version I set up a material - a mix of translucency and difuce, plus a little glossy. A similar material to what you had, but with seperate shading nodes rather than one principled… also note I turned on "Backface Culling’ in the material properties.

1 Like

Point light is not tangible. You need an emission material on a actual tangible object for it to show up in the transparent object. But emissive surface in eevee does not emit directional light so you need extra lights to illuminate the scene or bake the indirects.

To illuminate the mica shade you will need to rely on the surrounding indirect which means you will also need to bake an irradiance volume and make the object slight rough.

You can mix in a emission shader to tint the shadow somewhat but personally i don’t think it looks all that great. (needs baking)

2QuestionWhyDoesMoonlightSHineTHrough.blend (4.3 MB)

1 Like

So your methode works out to make this look right even in evee Thank you !