Thanks for the question. Effects doesn't currently have the camera information exposed, but you can achieve this using the Tint By Object effect and selecting the Camera as the object.
That said, I'm attaching an improved version that adds a Minimum and Maximum distance as well as a falloff curve to make it more flexible. To use it, ensure the following:
- The Forest Colour map should have Tint Override = Disabled
to allows Forest Pack to control the tint values.
- In the Forest Colour map, set the Blending mode to Normal.
- Use the Forest Colour map as a mask to blend between maps or materials as required
- In Forest Pack, set the Material > Random Tint > Random Strength >Min and Max to 100%
I hope that helps, please let me know if you have further questions.