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Make Opacity 0 In Negative Z Space
Hello,
I was just wonder, how might you use an expression to control a layer’s opacity when it moves beyound 0 in the 3D world.
I understand that 0,0,0 = X,Y,Z
When a layer moves into negative values into Z based on it’s world position, not by actually moving it, I want the opacity to = 0.
Example, I have a layer attached to a null, and the null is rotating on the Y. When the layer connected to the null moves into negative world space on the Z, I want it’s opacity to = 0.
Below is what I want to do:
In the above example, opacity is dipping down when the layer moves into negative Z space. How might I do this with expressions?
Thanks a lot 🙂
Guiboche
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1 Reply
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Well, no one replied yet, but I figured it out 🙂
The expression is
a = toWorldVec([0,0,1]);
b = position – toWorld(anchorPoint);
c = dot(a,b)/length(b);
if (c > 0) 0 else valueYou change the 0,0,1 to 0,0,-1 for in front or behind.
Later
Guiboche
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