1 Frame rendered in Cycles with original settings (~11sec)

ref image Cycles

1 Frame rendered in Cycles with thibsert's suggestion (~6sec-8sec)

enter image description here

1 Frame rendered in EEVEE for reference (~330ms)

ref image EEVEE

1 Frame rendered in EEVEE after some tweaking with the settings (~1100ms, 128 samples)

ref image EEVEE 2

1 Frame rendered in EEVEE after further tweaking (~310ms, 32 samples)

ref image EEVEE

Relevant settings for thibsert's way:


The important thing seems to be to keep samples low (~40) and use denoising, previously I tried this option with too many samples (~2000) and noise threshold together with motion blur active which caused problems

Some issues with this method:

  • The CPU bottlenecks the process while Denoising
  • Low samples size might cause problems for indoor scenes (haven't tried yet)
  • The GPU & CPU usage spikes up and down for each frame render (idk if relevant, just wanted to point that out)

Relevant settings for the tweaked EEVEE frame:

  1. Changed my point Light Radius from 0m to 0.01m which enabled the white bit of intense light at the top of the green ball
  2. Enabled & tweaked Ambient Occlusion in render settings to get the nice shadow below the green ball (side note: default settings kinda suck)
  3. Enabled & tweaked Screen Space Reflections, the default settings will give quite similar results to cycles but I wanted less reflection on the ball
  4. Added an Irradiance Volume that covers the road and baked it, default resolution worked fine for my scene
  5. Changed Shadow Size to 4096px in render settings

Some issues with this method:

  • It can look worse up close compared to cycles
  • Shadows might be a problem in certain scenes
  • The Irradiance volume might have problems when 2+ deforming/animated meshes need to provide indirect lighting to each other, you would prob need to bake it for each frame (However I want to point out that with static meshes it works great when 1 animated object enters a baked area)

What I'm trying to accomplish (half-achieved):

  • Re-rendering the scene with Cycles faster after making changes in the scene (for ex: changing the way the camera moves slightly)
    Alternatively: A way to accomplish better quality with EEVEE at the cost of some render time

Current Render Times (30fps):
~3 minutes in EEVEE
~1 hour in Cycles

Old Render Times (30fps):
~3-6 minutes in EEVEE
~2 hours in Cycles

Side Note: I would like to try to use Region Render but my ball & camera moves in the scene, can I somehow easily change this movement to fake movement that just moves the scene?

  • 1
    $\begingroup$ Did you try using Denoising, with a lower noise Threshold? $\endgroup$
    – thibsert
    Mar 15, 2022 at 13:29
  • $\begingroup$ I just tried however Denoising seems to be very heavy on the CPU causing a bottleneck. The result is that the time it takes is actually slightly longer for each frame. Edit: the GPU spikes (~100%) when processing samples and then the CPU goes to ~90-100% while processing the Denoising, going down to ~10% when GPU spikes up again for the next frame $\endgroup$
    – IGame4FUN
    Mar 15, 2022 at 19:51
  • $\begingroup$ thibsert I tried your suggestion with some alterations and got better times (reflected in the post now) please make a comment so I can highlight it for anyone looking for an answer here :D $\endgroup$
    – IGame4FUN
    Mar 16, 2022 at 12:26
  • 1
    $\begingroup$ You shouldn't be rendering at final quality to judge changes you've made. Render at low quality/resolution until you're happy and then do the final render. CPU will top out while denoising, there's not really anything that can be done to make it more friendly. $\endgroup$ Mar 16, 2022 at 17:39
  • $\begingroup$ well I'm just rendering 1 frame or putting same settings in viewport to test, I'm not actually rendering the entire animation at final quality each time xd, I just calculate how much that would take based on how long the average of 2-3 frames I render is, EDIT: I'm currently trying to learn so I don't know what my final settings are for any scene or what I need to change at all $\endgroup$
    – IGame4FUN
    Mar 16, 2022 at 17:46

1 Answer 1


Post Summary:

Get better quality in EEVEE (in general):

  • Change Shadow Size to 2048px+
  • Make sure your light source has >0.01m radius
  • Enable & Tweak Ambient Occlusion
  • Enable Screen Space Reflections
  • Add Irradiance Volume for indirect lighting

Speed up render time in Cycles:

  • Use GPU Computing (in general)
  • Lower samples count (~40) & activate Denoising (courtesy of thibsert, specific for my scene)
  • Use Fast Global Illumination preset for Light Paths (specific for my scene)

Side Note: I won't mark this as the answer because it doesn't really answer the post title question (which is asking for optimizations on repeated renders specifically)


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