Jump to content
garf

Tips needed: Very refractive renders

Recommended Posts

Hi all,

 

I'm rendering some jellies, in water, in a glass tank. Any pointers as to how to optimise this?  My render times are huge. Using mantra.

Edited by garf

Share this post


Link to post
Share on other sites

with mantra, this will inevitably render long, I'm afraid. not sure what are your settings and such and how much render time are we talking. there may be ways to optimize, without inspecting the scene thou it's really hard to say anything relevant. but in general, for heavy refractions, mantra isn't a great choice.

Share this post


Link to post
Share on other sites

Yes, it took so long! My little ice render, with such low quality, still took more than 1 hour for one frame.  Obviously I don't know how to optimize it.

Share this post


Link to post
Share on other sites

thanks for the confirmation - I probably should have gone with redshift for this shot.....

Ive swapped principled shaders for classic shaders, reflect/refract limits to 4, ray bias as high as I can, .rat textures and hdris.

Share this post


Link to post
Share on other sites

As said, it will render long no matter what you do. But you could try to reduce the ray limits even further and set "At Ray Limit" to use light color. If you have fireflies reduce the color limit.

Share this post


Link to post
Share on other sites

If you're getting a lot of noise the reflection / refraction channels, switch the brdf in your shaders from ggv to Phong ( I know I hate phong too ), last I saw, it was impossible to get sharp reflections with ggx, creating a lot of noise and a lot of extra render time to clean up. We covered a lot of that here, if I can find the conversation.

 

Also I assume ( and hope ) you're not trying to use indirect diffuse? Maybe if you can get away with no motion blur, do that - just throwing out ideas - iirc, reflection doesn't need as much ray depth to look good as refraction does, try refl at 2?

btw what do you consider "huge" render times? Some people think that's 10 minutes.

Share this post


Link to post
Share on other sites

"btw what do you consider "huge" render times? Some people think that's 10 minutes" - I'm talking 10+ hrs on 16 cores

 

 

Share this post


Link to post
Share on other sites
8 hours ago, garf said:

"btw what do you consider "huge" render times? Some people think that's 10 minutes" - I'm talking 10+ hrs on 16 cores

sweet jesus! what res is that?

can you post any kind of scene, I'm sure we can whittle that down to size

Share this post


Link to post
Share on other sites

4k - I can't upload a hip at the moment. I've resorted to a lot of comp trickery and some brute force to get this one out the door. I'll try and make a sample scene next week.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×