Rendertime and Max Transparency Levels issue

[sebastiaaan]

Hey,

I'm rendering quite a long time a frame (about 13h), that's obviously far to long. At FMX you guys had the great tip to reduce the Max transparency levels. Thats what I did (from 50 to 5) and now I'm down to 2 1/2 to 3h, without noticeable changes in the picture, execept that spots in the image which need more transparency levels (at least that's what I think) turn completely transparent. Is there any way to fix this, without putting high numbers in transparency levels again?



Kind Regards,
Sebastian

[vlado]

What kind of geometry is the hair and what kind of material does it have?

Best regards,
Vlado

[sebastiaaan]

Hey Vlado,

thanks for your reply! That's Maya Hair with a Vray Hair Material. The transparency issue does also happen on the leafs of the tree (vray2sidedmaterial <- opacitiy mapped vraymtl).

Cheers,
Sebastian

[vlado]

Then specifically for the hair you could try a material with refraction and IOR of 1.0, instead of opacity. Then you can control its trace depth separately.

Best regards,
Vlado

[sebastiaaan]

I'm not sure if I understood this correctly, I'm supposed to switch the Vray Hair Shader to a normal Vray Material and control its opacity through refraction? I'm actually really liking how the hair shader looks, isn't there another way to make it render faster, without loosing the Hair Shader?

(The Hair Shader has Opaque Shadows, Opaque GI and cached GI enabled (didn't like simplify for GI). It also has a V Ramp plugged into Transparency, controlled by a Vray Hair Sampler Node, to get a tip fade.)

Kind Regards,
Sebastian

[vlado]

Oh, sorry, I thought I read VRayMtl material. In that case, you can do the reverse, keep the VRayHairMtl for the hair, and use refraction for other things. Or you could turn off the transparency in the hair shader and make the hair tips actually thinner.

Best regards,
Vlado

[sebastiaaan]

No problem Thanks, I will try that. However is there a way to get the Hair Shader rendering fine (without the completely transparent spots in the final image) with a Max transparency level of around 5? Because the standart value of 50 is killing my rendertimes... . Or does that just not work with any transparency mapped?

Cheers,
Sebastian

[griml0ck]

If you render the hair as a separate layer you can use different render settings for the other layer. And you can use a much faster shader (vrayMaterial without opacity for example) on the hair when it's not visible in the other layer.