I want to make pizza shape (circular section) for skill collision.
Should I use
1 convex hull
1.1 convex hull to make pizza shape with thickness.
1.2 cylinder with triangular prism(create from convex hull).
3 cylinder with triangle.
Or there are better way to do this
It seem I can't see triangle for some reason. Is this normal?
I use triangle constructor
If you don't need contact-level precision, you could also do something like check the position of other objects relative to the query. If the distance squared is too far or if the dot(normalize(objectPosition - queryPosition), queryDirection) < cos(maximumAngle), then the object is outside the slice.
It seem I can't see triangle for some reason. Is this normal?
Triangles are one sided. They don't generate collisions on their backface. The demos renderer renders them as one sided too, so their backface is invisible.
Is it mean if some part in but center of mass is outside then it is no collision?
Basically, yup- if you don't actually care about the shape and just want to know if a representative point is in your query, there's no need to use a full collision test.