Reduce VRAM usage


Hi, I have a little problem. I’m going to create some big project with a lot of photos and videos as textures. Last time I did such a thing I encountered problems with rendering. Blender was crashing due to lack of video card RAM, because it was loading all photos (few hundred) for each frame (there was one maybe two visible at the time). I managed to render it by running blender in console, but it barely fitted into VRAM. Is there any way to reduce usage of memory or somehow tell blender that this texture that appears at frame #1234 won’t be necessary at frame #12? If it’s possible I want to have whole project in one blender file, but I can split it if it’s absolutely necessary.

PS. I’m rendering with cycles at 4K resolution and around 120 samples.

48GB of RAM
GTX1060 6GB

(CarlG) #2

Cycles won’t know if the “invisible” textures will not contribute to ray bounces (reflections, diffuse lighting etc). Any chance you could assemble these into a few video clips so that only two or three are visible at the same time in frame (i.e. thinking like panning across 100 monitors with different content with only 2 or 3 in frame at any given time)?

(Tomáš Luža) #3

try to render with GPU + CPU or with CPU only. CPU only might be a bit slower but with 48GB RAM you shouldn’t be having problem with memory limits.



Rendering with CPU is not a bad idea. Is there an option to set distance in which cycles will look for ray bounces?


Cycles is a Raytracing Renderer, for setting a distance you would need a Raymarching Renderer.
Nevertheless, you could optimize Cycles for rendering, like Simplify --> AO Bounces: 2 or 3 comes to mind or use Eevee Renderer, if this is an option.

(Tomáš Luža) #6

Yeah as stated above simplify in scene TAB is probably your best shot.

(TheTuxedo) #7

You can animate render visiblity with keyframes.

Select one of he objects, and in the outliner move the mouse over the camera icon and press ‘I’ to keyframe it on or off depending on when it should be visible.