a "diffuse" coloured shadow problem

[serrag]

Hi,

I am doing some interior-test with the new V-ray in Sketchup (7.0).
I am using 2 basic-colours materials straight from sketchup (red and white).

What I don't like because I can't uderstand is how to controll the "diffusing colour" of the shadow.
The shadow-colour of the cube on the plane. I don't know if it is the right word..but please look at the image for a better comprehension.

Why is it red?


Is it a material problem?
or something in the rendering setting?
(I am using gi_irmap with no physical camera)

thank you

Serrag

[orei]

Re: a "diffuse" coloured shadow problem

maybe it settings of reflection is too high?? try to reduce the ior reflection?

[serrag]

Re: a "diffuse" coloured shadow problem

there is no reflection layer.

the materials are straight from sketchup....

[40th]

Re: a "diffuse" coloured shadow problem

It's the color that bounces of the saturated surface. Go to Indirect Illumination and lower the Saturation value till you satisfied with the result.
Note: this affects all GI saturation.

[serrag]

Re: a "diffuse" coloured shadow problem

YES!
thank you very much!

I'm just wondering.... is there any value closer to the real-world light?

[dkendig]

Re: a "diffuse" coloured shadow problem

Well in the real world, if you had a white room with a red box in it, and light hit the box, the walls would appear red due to the reflected light from the red box. So actually you're trying to be less realistic.

[thomthom]

Re: a "diffuse" coloured shadow problem

midn you - are your colour values, 100% red and 100% white?

[serrag]

Re: a "diffuse" coloured shadow problem

dkendig: I understand what you mean...but I think that the reflected light is too much in some-circumstances... and why I can not controll the single-reflected-light-material..... ?

thomthom: yes, but I will make some more test tmrw

thx for the support.

[thomthom]

Re: a "diffuse" coloured shadow problem

try without using the full intensity of the RGB channels.

[serrag]

Re: a "diffuse" coloured shadow problem

My "real" problem is on an iterior room.

I have done a simple versione of the problem here.

I can't believe that in "reality"
in a room with a red floor, if the wall are white-matt (226, 226, 226),
I can see a "pink" ceiling due to the red (255,0,0) floor....


but with saturation 0,

it looks....almost ok.

any other suggestion?

thx!

[40th]

Re: a "diffuse" coloured shadow problem

As I said before, you should lower the saturation till it looks good enough. Setting the value to 0 is not a good GI solution.

[thomthom]

Re: a "diffuse" coloured shadow problem

Have you tried without full intensity on the RGB channels yet?

[serrag]

Re: a "diffuse" coloured shadow problem

thomthom, Yes it is little bit better but the red is getting too dark..

[thomthom]

Re: a "diffuse" coloured shadow problem

How much did you reduce by?
The thing is that 255 can often cause problems as it's at the far end of the scale. So usually try to reduce by a little amount.

[serrag]

Re: a "diffuse" coloured shadow problem

untill 190 same problem.... but it is already getting too dark...