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Flickering when using Light Cache


Ardak
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Hi, I am rendering animation using Light Cache. The problem is that I am getting small flickering on the scene, especially in places with lots of detail. The scene has vegetation and trees, and those flicker a bit. I have noticed that there are differences what antialiasing filter is used, but of course that loses detail also. So is there other options to make the flickering go away? I am using Light Cache for primary -and secondary bounces. I am not using Irradiance Map, because even when precalculated, it takes too much time to render, and I may like better the final image produced with Light Cache than with Irradiance Map, atleast in these particular scene. Thank you.

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i always use precalculated LC and IR. IR @ Medium (animation). AA settings do have a large impact on geometry flicker and crawl as you say. Using a quadratic filter with min1 max 10 settings always solves this problem for me. I have never used (or heard of anyone else using) LC for primary and secondary for animation, but let me know if you get good results, if you could post a sample of your final animation that would be awesome. Good luck!

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So, here's scene rendered with Light Cache with Fly-through for primary -and secondary bounces:

 

lightcache2.jpg

 

Rendering time approximately 8 minutes.

 

Here's the same scene rendered with Irradiance Map with Medium (animation) preset for primary bounces and Light Cache with Fly-through for secondary bounces:

 

irradiancemap2.jpg

 

Rendering time approximately one hour.

 

And I have lots of rendering to do, it would take me months to render with Irradiance Map, and frankly, the results with Irradiance Map aren't that cool, atleast for my eye.

 

Camera settings:

 

VRay Physical Camera

All are default pretty much

Film Gate: 36mm

Focal Length: 44,663mm

ISO: 100

Exposure: On

Vignetting: On with value of 1,0

White Balance: D65

F-number: 8,0

 

And other settings:

Image Sampler: Adaptive subdivision

Antialiasing Filter: For now VRayTriangleFilter with size of 2,5 (experimenting different filters)

Though the flickering is not destructive with this filter, it is somewhat noticeable.

Color Mapping: HSV exponential

Adaptive Subdivision Image Sampler

Min.rate: 0

Max. rate: 3

Edited by Ardak
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i always use precalculated LC and IR. IR @ Medium (animation). AA settings do have a large impact on geometry flicker and crawl as you say. Using a quadratic filter with min1 max 10 settings always solves this problem for me. I have never used (or heard of anyone else using) LC for primary and secondary for animation, but let me know if you get good results, if you could post a sample of your final animation that would be awesome. Good luck!

 

Where exactly I can set the min 1 and max 10 for quadratic filter? I have only option of setting it on.

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Adaptive subdivision is causing your flickering problem (flickering details). Use Adaptive DMC instead and set you max/min rate to 2/4 or 2/6 (I typically use 2/6). Adaptive subdivision is probably also causing your excessively long render times too.

 

I'm curious to know what you IR map settings were when you did your LC/IR map test.

 

E

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irradiancemapsetup.jpg

 

Here it is. And the settings you suggested above did not seem to have effect on the render time, sadly.

 

The mode should be set to either Multipass Incremental (for your GI pass) or to 'From File' for your 'Beauty Pass'. There is no reason that the mode should be on 'Single Frame' if you are rendering an image sequence.

 

If you are unsure have a look at this from the VRay help files....

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And if you guys see from the example pictures, the use of Irradiance Map produced some strange lightning artifacts on the plants, in addition that it takes massively more time. How should I render few animations length of 600-1000 frames if one frame renders in about 20-60 minutes?

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  • 1 year later...

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