Unable to create a simple cup-like hollow cylindrical shape


I am new to this and I really appreciate your help.

I am trying to create a cup-like hollow shape, on which I can eventually aim and throw paper balls at. Just a basic game (like a paper toss). But, needs physics and shapes and collisions.

But anyways, I am trying to set up a cylinder that looks like a hoop.

The problem is…when I set up a hollow cylinder, I am not able to see the inside of the cylinder. It is blacked out.

This is what I am seeing…


I want it to look like (ultimately)…


I would really appreciate your help on this effort.


Setting the culling to off might do the trick. Else, give it some thickness as a model.

1 Like
@memonick said:
Setting the culling to off might do the trick.

which you can adjust with:


thank you guys.

Setting the culling to ‘OFF’ helped with the visual perspective of the cylinder.

However, now I am running into a different issue…

As I had mentioned before, I am setting up a hollow cylinder as so:

Cylinder cup = new Cylinder(samples, samples, cupBottomRadius, cupTopRadius, cupHeight, false, true);

So, for the purpose of my game, I used the ‘Hello Physics’ tutorial and created such a hollow a cylinder on the floor, successfully.

However, after giving the cylinder rigidbodycontrol as so:

Geometry cup_geo = new Geometry(“Cylinder”, cup);

cup_phy = new RigidBodyControl(25f);



When I attempt shooting spheres (balls) at this cylinder, they are bouncing right off the top surface of the cylinder…

I was expecting, as it is a hollow cylinder, the ball would fall in the cylinder.

Thanks sooo much for your help so far. I really appreciate your help on this…

The visual representation of the Cylinder, even if the top is black, is still a SOLID cylinder. It’s not a tube.

I would personally opt for a model. A whole less hassle.

As madjack says, also you should look up convex polyhedra on google. A lot (like, almost all) collision algorithms assumes convex shapes. So you will not find a 1-step object that is a wastebasket. You will have to model it using compound shapes or do what computer games usually do - fake it :slight_smile: