Slow render times with procedural textures

[Guest]

Hello,

I am currently working on a project which uses cast iron type materials. To create these I have used a combination of cellular and noise procedural textures in the diffuse, reflection and bump slots. The renders look great and exactly what I need however they are taking far too long to render. Its 2 and half hours for a full HD frame of an animation. Normally we like to keep our render times to around 30 minutes per frame if we can. I am looking in to ways I can reduce the render times and thought that perhaps the procedural textures are the cause? Would it be any faster if I used texture maps of cellular and noise instead?

The render times do speed up to an hour and a half frame if I remove the maps from the reflection and bump slots and just have the diffuse and a solid reflection colour but it no longer looks and feels like cast iron. Also wondered if there are any other material tips and tricks I could try to get the render times down? I have stripped lights down to none HDRI plus turned off GI and it doesn't make a dent in the render times so its definitely the materials.

Thanks,

[vlado]

Can you post a screenshot of your material network? Would it help to use a VRayOverrideMtl material and use a simplified version of the main material for reflections/GI?

Best regards,
Vlado

[Guest]

I am mainly working with two materials in this project. Both are quite slow at rendering but the slowest is this one which uses a splat texture in the diffuse (the other uses a cellular texture). I have noticed that keeping the splat texture in the diffuse but removing the reflection and bump noise maps makes very little difference to the render times. Since I posted on the forum I also tried using just a texture map of a splat pattern to see if that would reduce render times but it didn't.

If I remove all of the procedural textures from diffuse, bump and reflection but keep the same glossy and reflective colour values it renders in 1 hour 40. So it leads me to believe it is the splat pattern in the diffuse which is causing the almost 1 hour increase in render time.