Chaos Corona Forum
General Category => Gallery => Work in Progress/Tests => Topic started by: Chakib on 2012-11-01, 16:54:19
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Hi guys,
This is an interior that i did time ago and i wanted to render it with the tasty Corona
After i did convert all vray materials, i did use an night hdri map for envirenement, but the problem is the noise was annoying my scene, but i give it 7h30 to render hoping to have a clean one,
Some weird white dots are visible, and it was difficult to adjust the texture without filtering, especially the bump value fore example the wood floor i did use a really big value, but i saw that i did wrong.
also the texture of my sofa without filtering destroyed the sofa shader, show it like a paper sofa lol
anyway i did use a lot of poswork in photoshop and Afterfx and this is the result ( downscaled of course )
Dof used is the corona dof. I will test the daylight version next time and trying to fix the materials.
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Is this noise connected with the env map? Tried making low-resolution env map for reflections?
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Is this noise connected with the env map? Tried making low-resolution env map for reflections?
I think yes because i did test corona daylight without env map and the render was fast with less noise in the first 20 min...
i did use pt+pt with 16-10
when i use HD cache, the light of the lamp doesn't penetrate the lamp shader , but with PT it does...
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Did you try with a gradient map instead of the hdri for the exterior environment?
I never tryed the other models of the CoronaSky, but it seem you can edit colors to simulate a night sky.
Maybe you could use just a simple dark color...
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Is this noise connected with the env map? Tried making low-resolution env map for reflections?
I think yes because i did test corona daylight without env map and the render was fast with less noise in the first 20 min...
i did use pt+pt with 16-10
when i use HD cache, the light of the lamp doesn't penetrate the lamp shader , but with PT it does...
I think you should make a low resolution image for HDR lighting and another one for background or add background in post.
What material did you use for the lamp?
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HDRI size should not affect render times
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There should not be any significant difference between PT+PT and PT+HD when it comes to light passing through the light shader, and in case there is, i would rather use PT+HD, and increase translucency of light shade, than use PT+PT, because PT+HD will give you a lot more reasonable rendertime.
I believe many of the problems in your scene might be caused by improper material setup. Material converter by DeadClown is really great for MR's Arch&Design materials, but is not remotely reliable for Vray materials.
My suggestion would be to:
1: resave scene as a new file
2: delete all materials
3: apply diffuse gray (RGB 160 to 170) material on everything
4: set GI to PT+HD
5: hide glass in windows and do the lighting first (enviro HDRI + interior lamps)
6: unhide glass planes in windows, create glass material for them, and make sure they don't impact performance (twosided glass material)
7: start with materials of objects close to light sources, such as lamp shades, and observe how they affect amount of noise in scene, avoid glossy refraction if possible, and use translucency instead. Avoid using opacity value at all cost if possible.
8: add rest of materials one by one. Make sure you have control over them, so do them manually (no conversion)
9: for optimal performance, try to avoid fakes, especially disabling shadow casting.
It might imply that if you disable shadow casting of a light shade for example, it will make rendering faster, but in Corona, it can actually impact performance in a negative way.
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HDRI size should not affect render times
ORLY? Here's a quick comparison.
30s_hi.jpg:
render time 30s
PT only, 16 samples
HDRI env map size: 6000x2900px
30s_lo.jpg:
same render time, same settings
HDRI env map size: 300x145px
It's only a 30s rendering, but noise difference is significant. Using a downsampled or blurred hdri as env map always helps reduce noise, especially on glossy surfaces with bump maps, because it becomes more uniform in terms of colours and intensity.
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This is an extreme case, you've modified the scene description a lot by blurring the map. And even then I would say that the difference isn't huge.
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@andreupuig : I did try corona sky, but i've wanted an envirenement image outside, so i did use hdri, but since i can't exclude the bended plane with and image emission material, i did use the hdri source.
@maru : I did use the translusuant simple corona material with value 0.5
i don't think the hdri size will affect the render, but in vray i think it does.
@Rawalanche : thanks for tips, but i did verify every object materials after conversion carefully, i didn't foudn anything strange the materials were clear to me. maybe my render parameters are not well chosen, i'll apply the hd cache again and see of the lamp will be good or not. I did use the twisted thin glass since i've read here that it's good for windows and for sun light throught glass. One thing that's annoying me is the bump value, sometimes is act good sometimes it doesn't appear even in the highest value, or it's just me maybe...
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One question please : do you use the gamma correction in your corona renders ?
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Have you tried using a plane with CoronaBgMtl on it for directly visible background override?
Yes, using gamma 2.2 ensures that you work with color spaces in rendering properly. Although you could change the value to get some artistic control, disabling it (gamma 1.0) is VERY bad idea.
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Have you tried using a plane with CoronaBgMtl on it for directly visible background override?
Yes, using gamma 2.2 ensures that you work with color spaces in rendering properly. Although you could change the value to get some artistic control, disabling it (gamma 1.0) is VERY bad idea.
I tried the coronagbmtl and it works great, thanks !!!
yeah i use always 2.2 with corona since with 1.0 the colors are washed.
here is the daylight result :
PT+HD are used here
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Thanks guys for your helps, indeed the HD cache is very useful and fast i like it after 2h30 of rendering with full DOF etc ( in vray it took me more than 6 hours without dof with high quality preset lol )
Here is the final result
I tried to achieve the white bricks effect for the wall but the displacement crashes max when i hit render, i don't know why ! so i just apply a bump map and diffuse map only.
I'm pretty satisfied with the daylight version, will try later the night one.
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The last one looks best so far. I would reduce the amount of bloom on background, make it less strong and larger, more like soft screen around windows. Rest looks good :)
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The last one looks best so far. I would reduce the amount of bloom on background, make it less strong and larger, more like soft screen around windows. Rest looks good :)
Done i've updated the finak image.
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Update : fixed the too much bloom effect.