Real-Time Physics Simulation Forum

Hello wilcof Bullet and Ogre are a nice combination for such projects, especially if you do not want to use any high-end graphics stuff, it is very easy to integrate bullet into any graphics engine. Ogre is a very decent engine, I wrote a simulator in it using bullet physics as a physics engine (May...

I realized that you maybe have a different definition of inbetween. If two planes can be used, you can basically just use basic math to determine if your camera is in front or behind the planes: The general prodecure would be this: vec normalA; vec AB = B - A; double dot = dot(AB, normalA); bool inF...

Produce a convex hull out of the eight corners of both portals. In your case it basically means you create a box out of these eight corners of which two sides are the portals. Now you can use a convex hull algorithm which tells you if the point the camera is located in is within the box (or in gener...

If you want performance, do not try to use your OpenGL meshes to detect collisions. You should use an approximation of it built from the primitives. So if your mesh looks a bit like and mainly behaves like a sphere, use a sphere. If a capsule is better, then use that. Things like characters are usua...

Problem solved. It is that I rotated the inertial of the urdf body. If your base has an orientation != Quaternion(0,0,0,1) when placed into the world such as this one: <link name="link_8"> <collision> <geometry> <cylinder length="0.2" radius="0.025"/> </geometry> <origi...

Aaw, cool! I was a long time player of your game (really liked it!) and now I find out that it runs on the physics engine we all know and love! Great job!

Wht is your physics step? Maybe everything is just so fast that everything has to tunnel through everything else. Furthermore, what are trying to simulate that you want the same movement regardless of mass?

Yes, multibodies are totally independen tof the collision boxes. They are not even necessary for it to work. You build up a structure of joints by providing how they are positioned in the local space and so the positions of your links are defined. If you then add your link collider, their centers of...

It is still pretty fast as the performance ray test example in the example browser shows. It also seems to be pretty fast in more complicated settings as in the more recent project on raytracing and refracting through high resolution meshes of human organs (search for it in forum, cool pictures!).

Hello, I produced a simple snake multibody (a chain of 5 links) and I am working ok a reinforcement learning setup to make it move. Therefore I need to reset the multibody, but when I use the standard resetBasePositionAndOrientation, this greatly messes up my multibody. It usually gets instable and ...

What does it mean for the joint position to drift when the parent object accelerates? Does that mean it gets an offset to where you would expect it? Is it the joint attachment point that drifts or is it just that the joint elongates because of the acceleration? For now I do not see what happens.

Yeah, flags are faster than other methods, but if you need more, you take another method to solve your problem. I am happy that you found a way!

Hello,

How about constraining a single object A to a point in space (position of object B) and then updating the point as you move object B around? Or what does it mean to not experience the force of the constraint?

Do you have a simple example of what is not working? Usually code segments are easier to debug than descriptions.

To set up the joint correctly, you need to define where the joint axis should be placed with reference to your links. Therefore you need to define those two vectors. Usually if is easier to define them in world frame or in a frame of reference of your choice, depending on where they are most intuiti...