Help with render time

I am relatively new to blender, have made this scene and am rendering out my final animation in PNG format at 35 samples and my render time is so slow (took 40 mins to render out 3 frames). I am running on a mac air so cant render out using GPU. Pleeeeeaasee help me, i need to use this for an assessment tomorrow! Halp


hallway scene.blend (1.61 MB)

In the render / performance setting reduce the tile size if you are rendering on the cpu

Also in the Render / Sampling setting turn off ‘Square Samples’ so you’re not rendering at 90,000 samples

Also I don’t see any change in the scene during the first 50 odd frames. Therefore you don’t need to render all of them. Just render one frame and use that for all those frames. Either duplicate and rename rendered image or use something like the sequence editor to extend that image over a range of frames

But you are using tile size for GPU which slows down CPU. Small tile size such as 32x32 is likely to be better.

Thank you both! these changes did make the render much faster, however when I turned off ‘square samples’ the image/render quality becomes much less and the image is extremely noisey/distorted and not as crisp as before. Should I turn my samples up in this case?

Thank you both so much for your help! I did apply these changes however when i deselect ‘square samples’ the quality of the render is considerably less. Does this mean I need to then increase the samples further?

Also, a clamp of 1 for direct and indirect (but no higher than that) will help clear fireflies without needing a ton of samples.

What squared samples does is it multiplies the samples by itself… so you set it at 300, so it was rendering 300x300 or 90000 samples.

What i would suggest, is if you are wanting less noise, increase it manually to 500 or 800 samples… 90,000 samples is excessive and unneeded.

If the main indirect lighting doesn’t change over the frames, I would also suggest baking out the lighting information once with good quality (and more bounces) at relatively high resolution, which may take quite a while. When reusing this info the image can be rendered at much lower amount of samples without loosing quality, at a much higher rendering speed.