[MAYA] Shader Based on Relative Distance from Camera?

TarsaE

Hello, everyone!

I'm working on a shader for a character. I want the parts closest to the camera to be a darker color than those farther away.

Right now I'm using Point Camera Z from the samplerInfo node to drive a ramp (which eventually plugs in to a surface shader). The problem is, the effect is lost if the camera zooms in or out because it's working with the absolute distance from the camera.

Does anyone have suggestions for how to set this up so that the parts closest to the camera are darker BUT the character has the whole color range no matter how close or far the camera is from the object?

Thank you for taking a look!

kodde

So this is for offline rendering I guess?
Use shaderfx for real-time?

kodde

I'd probably go for a setup where you let the camera z drive the blender value.

Something like:
Blender(MyColor1, MyColor2, Clamp(0, 1, (Camera.Z + MyDistanceOffset) * MyDistanceScale * MyMaskTexture))

poopipe

You need information about the object position and a bounding sphere/range in order to get a full range of values across the object regardless of distance from camera..

You have the position so you can just offset everything to the object's space


Edited cos I looked at the picture properly 

TarsaE

It will be used for a short animation, so not real-time.

I should explain, the ramp (dark to light pink) is for the main body, and then the blend node I have is used to overlay that with details like the hoof and horn colors. 

kodde -
I don't quite follow. Could you explain what you mean by offset and scale?

Thank you both for your help!

poopipe

What he's saying is that you need to create an area that is offset from the camera and use that to control your blend. 

Doesn't work based on your more recent post but the offset and idea of setting a range still apply

poopipe

Due to failing at using words I thought I'd make a picture

This will give you a gradient within a range defined by distanceOffset and distanceOffset+distanceRange. 

eg.  if you set distanceOffset to 100 and distanceRange to 100  it will blend colors  while the camera is between 100 and 200 units from the object

I don't know how ramp works as I don't really do much work with hypershade

TarsaE

Thanks for your help! I ended up combining pieces of both. It's a bit clunky, but it works.

Basically:
     * Find difference between Distance-from-Object-to-Camera and Distance-from-Point-to-Camera (which is constant for a given point no matter how close or far the camera is)
     * Remap that those values from the old range to a new range of 0 to 1
     * Old range min and max are driven by a control curve parented to the master camera for easy adjustment (necessary for shots with extreme perspective)
     * Use the new values to drive a ramp
     * Use the blend color node to overlay that with details (for examples, spots and hoof color)
     * Plug the whole thing into a surface shader