object casting shadows but not blocking skydome specular reflections

[jakob.littlewater]

Hi there,

I can't wrap my head around this. Is there any way to disable specular reflections without disabling cast shadows? I need an object to cast shadows, but be invisible to everything else. But the object always 'blocks' the specular reflections of my HDRi skydome light unless I disable cast shadows.... Even with a rayswitch shader won't help me there, same behavior... Any ideas?

Thank you!

Best Regards,

Jakob

[Stephen.Blair]

If I understand correctly, it works for me. I can disable specular reflections on the sphere, and still have its shadow.

I set the skydome to have red shadows

[jakob.littlewater]

Thank you for your quick response, Stephen! Sorry for being unclear. I meant an object stands in front of a mirror, and casts a drop shadow on a ground plane. And now I want to disable spec refl. The object appears black in the mirror, cuts out the reflection of the dome, and disappears only completely when I disable casts shadows.

[Stephen.Blair]

@

Ok, now I remember...

What you're seeing is because of the skydome light, which is sampled with shadow rays.
I don't remember the exact explanation, but when an object casts shadows from the skydome light, you also get the specular

I had a another case about this. We used shadow linking to get rid of the shadows (instead of disabling Cast Shadows). So we disabled shadows for just the skydome, and left shadows from all other lights.

[lee_griggs]

Would you be able to upload some images (win+shift+s)?

[jakob.littlewater]

Sure thing.

[brian_Foley]

You can create 2 skydomes.

1st - with all but spec

2nd - spec only and Cast Shadows off.

Sphere is light linked only to Skydome1 (no spec)

Mirror is light linked only to Skydome2 (spec only)

[jakob.schwarzAHQFZ]

Hey Brian, thanks for your answer. I already tried that. But as you see in the screens, then the reflection of other objects in the mirro get weirdly semi-transparent...

[brian_Foley]

Did you at some point turn off 'receive shadows' in the Render Stats of the Mirror Shape?