Z Depth After Effects

[DJTravisty]

Any good tuts out there on adding rain / fog to scene with Z depth? Need to brush up on some basics.

I also wonder if there is a way to drive a parameter in AE with a parameter from C4D?

I have lights in my scene imitating lighting that light up the scene. I would like my rain / fog AE assets to light up in the same manner. 'Screen' and 'Add' did not have the desired effect because my rain is still pretty bright on the dark sky background even with the lighting lights are off.

Any idea how to achieve the desired effect? I was thinking using the light intensity in C4d to drive the rain opacity in AE though I'd probably have to remap the values as well.

Lastly, I hope upping the resolution for the final will help the z depth map be better defined? AS you can see, because of the depth map, there are leaves just suspended in the sky there. In addition to that, is 128 samples good enough for z depth final render?

I appreciate the help!

[frankmci]

If I understand you correctly, I think you need to generate both a z-depth pass and a light pass, then use the light pass as a mask for the Z. This will only get you so far with a 2D fake, though, since the size and apparent speed of the rain won't change with distance. You can approximate it, though, by additionally using the Z pass to set up multiple distances/layers of 2D rain. That's simple enough by tweaking the z-pass luma curves to isolate specific distance ranges and scaling the rain effect appropriately. I hope that makes sense.