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Object collisions failing with fast movement
I am mapping phone movements to a cube via accelerometer/gyro and inside the cube are rigid bodies
Moving the phone around moves the cube, and the rigid bodies inside bounce around within the cube
Works but when the movements become too fast the inner objects always escape the cube (I have inward facing normals on the container with mesh a collider attached, but I have tried all types of colliders in every combination)
I have adjusted:
Solver Iteration Count
Min Penetration for Penalty
Convex + Smooth Sphere Collisions on colliders
Continuous/Continuous Dynamic/Discreet on rigid bodies
Interpolate/Extrapolate/None on rigid bodies
Fixed Timestep
Maximum allowed timestep
Attached DontGoThroughThings script to both objects
If I parent the interior objects to the outer 'container' the objects they don't escape
However they are not acted upon properly by the accelerometer to movement mapping (as children they move 'with' the container whereas I want the container to move underneath them, 'pushing' them by collision with outer walls to stay 'inside' the container
Attached is the simplified project It seems like I'm missing something simple?
Answer by robertbu · Aug 15, 2013 at 06:25 PM
What a through list. All I can offer you is a hack. Given the outer object is a cube, it is easy to detect when one of the inner bodies escapes and then take action. You can use the Unity's mathematical Plane class. The class contains GetSide function.
Something less computationally expensive is to compare the dot product of the side vector to a vector from the middle of the side to an inner object. The sign of the dot product will tell you which side it is on. Assuming a cube one unit on a side, you could do:
var point = outerCube.position + outerCube.forward * 0.5;
var vec = transform.position - point;
if (Vector3.Dot(outerCube.forward ,vec) > 0.0) {
Debug.Log("I'm outside, take some action to bring me back");
}
You would need to do this comparison for each side of the outer cube.
It may be a hack but its better than abandoning the entire scene. Thank you for the code it works for what I need.
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