Color = Distance?

[sonymng420]

Hello,
Here's a quickie: I am looking for a fast and easy way to have the color of an object change (darken) based on it's distance from the camera. For example, have a sphere be red at/past a said distance from an object, but fade to blue as it approaches a closer distance.

The reason for this is to darken a field of objects the further they get from the camera, but Fog is (sadly) not an option. I'm sure there's something similar that's be done before. Anyway, I appreciate any feedback people can offer to this dilemna! Thanks!

[stevesayer]

Look at the 'pointCamera' attribute in the SamplerInfo rendering node. It should be fairly straightforward to hook up one of those to your shader, and have the properties change depending on distance (I might suggest connecting to the 'diffuse' value rather than the 'colour' value).

Good luck!

-Steve

[pixho]

Hi all,

Yes, use the pointCameraZ (from samplerInfo) to modify the color / shader with the distance.

For a fog fake, create a samplerInfo, a setRange, 2 surfaceShader (the 1st is the assigned mat. to the object and the 2nd is the fog's color) and a blendColor.

Connect the pointCamZ to the inputZ of the setRange, connect the outputZ of the setRange to the blendColor.blender.
Plug the output of the blendColor to the 1st surfaceShader, and finally connect the outColor of the 2 shaders (2nd surfaceShader and your material) to the color1 and 2 of the blendColor.

When you have your network done, assign the first surfaceShader to your object.
You'll have then to clamp the resulted distance in the setRange (minZ 0 maxZ 1) and the oldMinZ is the nearest distance from the cam, and oldMaxZ is the farthest distance (because the axis of the pov through the cam is -Z)
Adjust the oldMinZ and oldMaxZ to see your object being faded as it gets closer or farther from the cam.

You can refine your fog's surfaceShader by mapping it with a 3d fractal or whatever 3d 'turbulence' texture...

Good luck

Emmanuel

Emmanuel Campin
Lighting & shading TD
www.pixho.com

[sonymng420]

Thanks or the ideas, sounds like it's exactly what I needed!