Blur Image


I got a question. why do my image looks like this after rendering? Even with Denoise data and Denoise checked.

Screenshot 2020-03-18 at 5.05.22 PM

Try the denoise node in compositor instead. Turn off denoise, but leave the denoise data on, as some of those outputs can be used with the denoise node. My first attempt is always the main image output, denoise normal, and denoise albedo. But in some cases I might use regular normal and diffcol instead, and choose method using obj/mat ids or cryptomatte.
That said, it might most likely fail - especially in dark corners and areas. A lot of the energy in the image comes from bounced sunlight. And indirect light is always tricky, produces a lot of noise. 128 is just not going to cut it as a brute force sampler with heavy weight on indirect light.
I always start out with 4500K sun strength 441 and sky strength 29. Using real sun bounces, it can help to increase the sun size and bring down its power to simulate more hazy to overcast conditions. Render out an image with caustics for reference. Couple of options now are to add interior lights to even out the lighting, it should help with the noise caused by sun bounces. This can be combined with setting the sun to zero bounces, multiplying the sky strength by ten (290) and multiplying its sky texture color with the sun temperature (4500K). Reason this should help is that sky texture provide a lot more direct light. Obviously the output will not be identical, far from it, but it may be a beneficial for own projects where realism isn’t a huge deal. HDR is only for camera rays, it does nothing to the scene.

The reference render:

The no sun bounces render:

Exposure in both are 3, using Filmic. 128 samples, which is way too small for this one as microdisplaced popcorn ceiling is here also a source of noise.

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Thank you so much for your reply.

I followed what you wrote and it worked. Although I still have a lot to learn about lighting, I have learned a few things from you.:slight_smile: Thank you so much.

Oh, and btw, be advised that if you set sun bounces to 0, also the bright direct spot will not show up in reflections. In the above, note how the strip of light is reflected in the “TV furniture”, whereas in the bottom one it doesn’t show up. I think it should be possible to set it up using a node tree for the sun that only deals with diffuse bounces, but I haven’t tried yet.

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Noted. Thank you for the advise. I’ll play around with it a little more. :grin: