hdri issues

# 1 29-11-2006 , 12:54 AM

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I´m probably doing something wrong. everytime I use hdri with mental ray and FG the rendered scene gets colored by the hdrifile color pretty hard. I have never ever accomplished to render with hdri in a very normal daylight color. most time its completely blue or if clouds are part of the file (wich are somewhat slightly orange or redish) the scene renders out completely orange or red. addingly its allways too dark.

so - i could tweak color gain and offset, but that doesn´t give a admireable result too.

most tutorials simply create a hdri_node turn on FG, render and boom - beautiful picture. there´s never a problem with color saturation.

any tips?

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# 2 29-11-2006 , 10:47 AM

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well yeah adjusting the saturation of the map should be your first port of call. Do it in photoshop or shake etc. can you post the hdri? I'm just wondering if maybe it's in linear colour space or something and that's what's screwing you.

post it and I will take a look

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# 3 29-11-2006 , 11:10 AM

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i didn´t know how big the file can be to upload it, so I made it quite small. if you need it bigger, just tell. a small render is added too, where the color gain is set to 7 and color offset is 0.5. these are the values where the tower starts to get out of the dark. but I have to disable the visibility of the background cause its all just white now.

I used different approaches - from creating IBL-node to a sphere where the hdri is mapped to color, incandescence, ambient color. either the backGround is blown and geometry is visible, or background is fine but geo ist allmost black. guess I have to render it in passes.

thx for your help!

edit_ well it is still to big
I put it into jpg_format

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hdri2.rar (29.7 KB, 204 views)

everything starts and ends in the right place at the right time.

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# 4 29-11-2006 , 11:23 AM

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I threw it onto the image shack site. had to convert it to a .tiff file. but it is converted to png user added image

argh!

I could send it per mail.
but after all. it´s not just this hdri - its every hdri no matter if selfmade, evermotion or dosch design. it´s allways dark.

or am I just stupid and it is normal to turn up color gain and offset like that?

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# 5 29-11-2006 , 11:26 AM

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another problem ist that reflections are white only, no usable color information from the file. isn´t it possible to not render everything in a separate layer?

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# 6 29-11-2006 , 11:27 AM

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why don't you resize it down a bit and zip it and attach it here? Playing with teh colour gain etc etc is fine. As for reflection it will depend on the scene file.

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# 7 29-11-2006 , 11:38 AM

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i´d need the hdri sky + modeled environmet in my reflections.

500 x 250

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04_hdri.rar (186.2 KB, 188 views)

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# 8 29-11-2006 , 12:27 PM

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can you do it as a zip please? I can't open rar's here

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# 9 29-11-2006 , 12:35 PM

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nah, thank you!

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04_hdri.zip (190.2 KB, 189 views)

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# 10 29-11-2006 , 01:00 PM

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em that file you 've sent me is weird:

you said you're only seeing white reflections from the file. Well it's almost a black and white image. The clouds are nothing but white (I saw that in the lower exposures there is some detail but it's all black). So I wouldn't be surprised if it was just reflecting those.

there's no real colour information in that file to speak of apart from the sun. You wont have much joy with that map.

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# 11 29-11-2006 , 01:28 PM

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i used that map explicitly because of less color information. cause if I use any file which is slightly colored - say with a blue sky - the whole rendering gets completely blue. I inserted a directional light now to with some yellow color to compensate the blue tones.

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# 12 29-11-2006 , 01:51 PM

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no you shouldn't have to do all that!! user added image

do you have the original image?

I can try a quick test for you

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# 13 29-11-2006 , 02:07 PM

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the hdri´s color I posted is untweaked. I was using another hdri, which is coloring my scene in an unwanted blue tone. I can send you this

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dh004lp_300.rar (201.3 KB, 202 views)

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# 14 29-11-2006 , 02:24 PM

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could it have to do with the fact that the area around the probe is blue instead of black?

i rendered a plain sphere with a blinn attached and reflectivity on at like .1 so i could see what info the sphere is receiving, and the plain blue does show up in the reflection, so i would think that might be what's affecting your render.

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# 15 29-11-2006 , 02:53 PM

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if you map the file angular not spherical in the IBL node only the photography without the blue surrounding is used for rendering. it cant be for another reason, cause if using a bright hdri with slight redish clouds, the image gets tinted too red.

I dont know, maybe it has something to do with the shaders. .

everything starts and ends in the right place at the right time.

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