Combining Foliage Opacity Mask with another Mask

Development Rendering
1

I would like to make my foliage invisible below a boundary on the Z axis to create an automatic transition or fade out.

Currently, my approach is to create a material function that gives me a 3D box mask that cuts off everything below 0. It works great, but I’m having trouble combining it with the opacity mask from the Foliage. With the Append Node, I unfortunately lose the mask for the grass itself.

Is this the completely wrong approach for such a scenario? Does anyone have any experience with this?

Thanks for your help in advance!

MF_BoxOpacity
MF_BoxOpacity1593×661 155 KB

2

I’m guessing the function is ok, but can you show how you’re combining it with the rest of the material?

3

Oh, my mistake! Forgot the second picture.

But right now it is simply an Append node … I was just guessing and trying … :slight_smile:

BoxOpacityMaterial
BoxOpacityMaterial1322×665 165 KB

4

Use GetMaterialAttributes and SetMaterialAttributes nodes :slight_smile: You will save yourself from these ugly graphs :slight_smile:

5

Thank you @Rawalanche :slight_smile: Looks more organized now!

6

Yep. You no longer need to do pass through connection of the attributes you are not interested in modifying :slight_smile:

7

I think I found a solution:

Using a Linear Interpolate to blend between the original Opacity Mask and a value of 0 with the Box Mask as the Alpha Value.

BoxOpacitySolved
BoxOpacitySolved942×379 66.2 KB