Hello,

does anybody have an idea why the shadows are wrong with transmission enabled. (see attached files)
The 2. picture is with transmission in the shadow tab disabled - and the shadows are OK.

I use a leaf texture on a plant model made with onyxtree modeller. Raytrace transmission amount is 50%. Only 1 light. No GI or other gimmicks. EIAS 7.01 ppc-cfm

Thanks in advance
Michael

try apply same texture clipmap to transmission....

thanks, but there is no difference.
I also tried using a clipmap with alphachannel and without.
clipmap in clip channel and clipmap in transparency channel - nothing worked

In Transmission Maps?

Hi, Michael

Michael B. - 02 July 2008 10:54 AM

does anybody have an idea why the shadows are wrong with transmission enabled. (see attached files)
The 2. picture is with transmission in the shadow tab disabled - and the shadows are OK.

RT transmission (same as some others RT features) requires solid shapes with well-welded vertices. Otherwise artifacts are unavoidable. If, for example, leaves have no volume - use “usual” transmission instead of RT one.

Thanks Igors

Thanks Igors and CyberMODE,

yes, I had the clip tex in transmission maps.

I tried “usual” transmission first, but I can’t see any effect. With transmission amount 100%, color white (see attached pictures)

Hi, Michael

Michael B. - 03 July 2008 02:32 AM

I tried “usual” transmission first, but I can’t see any effect. With transmission amount 100%, color white (see attached pictures)

Heh, true, “usual” transmission is affected by shadow, so its effect is near zero with shadow ON. Need to find other ways like “shadow object only” etc. - but it’s ifor artists, we cannot help here.

Hi Igors,

OK, obviously there is no easy way to get this nice RT transmission effect with right shadows when using a leaf texture on flat rectangular polys.
Many thanks for your infos.

Michael

OK, my mistake was, I thought that turning off the ‘enable transmission’ checkbox in the light shadows tab would turning off all transmissions. But this is only true for RT transmission.

Hi, Michael

Such scene (Placer Deposit, right?) always was a pain, we remember it from old times yet. Leaves back sides are “unpleasantly black” and it’s not clear what to do. RT transmission is enough helpless for this kind of geometry. Maybe (just idea) render a layer (.psd) without shadow but with “usual” transmission” and then combine it in post-effect? Again - it’s just idea.

Here is our try in same area (10 years old). Heh, old good times.., 3D looked so easy and simple Nostalgia

http://homepage.mac.com/cake_or_death/Grass.mov

BTW: leaves “like” anisotropic.

Hello Igors,

here it wasn’t Placer , I made this with Dante.

I will try your idea with different layers and also the anisotropic shader. Thanks for that tips.

Best
Michael