All these 11 tricks have passed my test on Nvidia Geforce GT 610 2 GB, which is relatively an old GPU.
All my renders and artworks are rendered using it.
After the cycles render engine has been introduced into blender, there has been a drop in the render speed.
The #1 reason is cycles render engine calculates higher bounces which make the render more realistic.
Estimated Reading Time: ~9 mins
1.Get rid of extra polygons
- The object is too far from the camera. (LOD Technique)
- It is near the camera but out of focus. (Depth Of Field)
- Unnecessary levels of subdivisions.
- Highly detailed parts of the object don’t face the camera.
Here’s a little test with the decimate modifier and how far you can go: (hardly noticeable)
(The first model is high poly and then the models pass through a decimate modifier each time with 50% of the previous details)
|Rabbit model from Stanford 3D Models|
Again, you can completely delete the parts of the mesh which are not visible to the camera.
Sometimes, while rendering interiors you forget about some objects in rooms which are not visible to the frame of the camera. This further strains the memory, and ultimately reduces render speeds.
2. Distribute Calculations using Render Layers (Important: Exclude Layers)
This will completely isolate the specified layers when that render layer is rendered. Thus, blender doesn’t need to further calculate any reflection or bounces from the objects in the excluded layer.
Materials and Shaders
3. Cheating with Volumetrics and Volume Sampling
I have found a work around which has saved 10+ hrs during the rendering process of Caminandes 3 short film (I’m not a part of the team, but I mentioned the trick to one of the artists, on Twitter).
You can find the full concept used here.
4. Avoid Glass, Translucency, SSS (And how to fix)
5. Sampling Tab
The Sampling Tab has two options, path tracing and branched path tracing.
6. Turn off AO (Use AO Pass instead)
So, you can turn off AO directly in the scene and instead use the AO Pass which can be used to achieve more or less the same effect.
7. Are you using all the threads? (Only CPU)
8. Tile Size (Performance & Quality)
You can also use the Auto-Tile Size add-on by Greg Zaal to automatically calculate the perfect tile size (exact dimensions).
9. Light Paths
One more thing to consider is the more the difference between the maximum and the minimum bounces, the faster the render gets but it’ll also become noisier.
10. Large Light Sources
Thus, the bigger the source of light, the easier it is for cycles to calculate the light bounces.
11. HDRI Multiple importance Samples
1024 or 2048.
You can help your friend or artist who is learning blender by just sharing this with your network. Make sure you click on one of the share buttons.Have you found anything else to increase render speeds? Share it in the comments below!