Drawing on face

Can someone help me? I want to create an effect that the user can put things on his face or draw on the face using the finger. I searched a lot, but I can’t find a way.

Ideally we’d have some raycasting capability in spark, but I don’t think it’s exposed. They do raycasting to detect intersections for the plane tracker, but it’s not directly accessible to creators.

I think it would look like this threejs demo


Screen Shot 2022-05-09 at 9.25.44 AM

But, another way to do it is to take an unwrapped face texture and have the user draw on it in an “edit mode.” Then they can see the result on their face after switching back to “view mode”

If you want to place objects on the face, you could make a grid of small planes for the user to tap on. Spark doesn’t tell you where you tapped on an object, so this is a way to give you more accurate positions from the tap event