White Overlay In Rendering

[kale]

Hi all,

I have small question:

When I render in MR a box with Mia Material with image connected to Diffuse color, the box in the rendered image has a sort of whitewash over it. When I put a box next to it with solid color (no image attached) the color is ok.
The light set up is the Physical Sun and Sky light.

I thinks the problem is the attached image, anyone?

What can be the problem?

thanks Jeroen

[joojaa]

Well try to adjust the exposure control. Taht putting a physical sky form render global does. It gamma corrects all your colors by 2.2 wich will blow your colors unless you accounted for this.

[kale]

Thanks joojaa

I lowered the gamma of the mia_exposure_simple1 to 1.8 but it's still a little bit flat (whitewash). And the problem is that everything becomes darker...;-(

with 2.2 it was all very white

[joojaa]

Yes thats bacuse your monitor is boosted 2.2 you should push all your colors down by the inverse gamma of your monitor to get linear data then render witha 1.8 gamma otherwise you over expose the global illumination

[kale]

hi Joojaa

"should push all your colors down by the inverse gamma of your monitor". What do you mean by this, do I need to change colors in the image. The inverse gamma of my monitor: Gamma of monitor is 2.2 -> inverse is 1/2.2=.45 ?

These steps are a little bit new for me, can you please explain it a little bit further?

Thanks in advance

[adoubleu]

Hi,
Your problem is you need to un-gamma your file textures.

you can either put a gamma_correct node onto each of your file textures, (which can be a pain)

or

you can let mr take care of it easily by:

1. on the mia_exposure_simple node lower the gamma to 1

2. in the render globals, framebuffer tab, set the gamma to 0.455.

This should be a starting point so you won't have your textures washed out.

Then you can adjust your final gather and raytrace settings accordingly, and use the mia_exposure_simple node to control your overall image exposure. start off by playing around with the "gain" control and go on from there.

Hope this helps.