Reflection using expression

[Dan Ebberts]

You’ll probably want to use a different method to define where the floor is, but this should get you started:

floor = thisComp.height/2;
ballPos = thisComp.layer(“ball”).transform.position;

y = 2*floor – ballPos[1];
[ballPos[0],y]

Dan

[Dotan Stern]

Thnax dan
i tried that i used the expression on the reflection layer and now it goes with the ball but the intersection is in the middle of the comp how can i use it with the floor i have?
and i cant move both of the balls

[Dotan Stern]

I kind of figure it out and fixes the problem i had with both balls in the middle that was because the anchor point was at the buttom
anyway what i did was adding a camera and rotate around to look above the floor now it looks ok
but thats the right way do it?
if i have the comp this way :
1: “ball” 3d comp
2: “ball reflection” 3d comp
3: floor 3d layer
i dont wanna use a camera is it possible to do it this way? or the way i did was ok?

[Dan Ebberts]

Hard to say without seeing it.

Dan

[Christian Pulfer]

-Apply this to the Reflection layers Position
-Rename (“LayerName”) to fit the project
-Then you must invert the “Y” value in the scale
and apply any Masking and transparency you like.

x=thisComp.layer(“LayerName”).transform.position[0]
y=thisComp.layer(“LayerName”).transform.position[1]*-1
z=thisComp.layer(“LayerName”).transform.position[2];
[x,y,z]

Now precomp your floor layer with all it’s lighting and other related layers and stack the two layers (top and reflection layer) above the precomp of the floor.

You could also think about linking the transparency,
and/or a blur effect to the “Y” value.

Here’s another one that we created to include an adjustable horizon plane.

hor = 600 !//-double the y value of the OG Layer
X=thisComp.layer(“LayerName”).transform.position[0]
Y=thisComp.layer(“LayerName”).transform.position[1]-hor
Z=thisComp.layer(“LayerName”).transform.position[2];
[X,-Y,Z]

Good luck!