Simple box Physics

[bergerkiller]

Hello everyone.

I am making a game in the Java language (mind the prefix, it is close enough), and I got every aspect done. Graphics, sound and a game logic.

Now I have an issue with the physics. I have a dice (box) with 8 points. I need to simulate physics by changing the boxes rotation speed and velocity. I understand that I have to check if a point of this box pierces another box or is under the terrain, but then I get issues. I have to make the box "bounce off", and based on the location it must rotate a certain value minus some sort of factor, so it doesn't go bouncing around forever.

This code can *somewhat* do the "below height 0 physics", but it is pretty buggy since it does not take account to its own velocity:

public void move(float forceX, float forceY, float forceZ) {
        this.velocity.add(forceX, forceY, forceZ);
    }
    public void rotate(float rotX, float rotY, float rotZ) {
        Vector v = new Vector();
        v.x = rotX;
        v.y = rotY + Common.sin(this.location.pitch) * rotZ;
        v.z = Common.cos(this.location.pitch) * rotZ;       
        this.rotation.add(v);
    }
    public void push(Vector location, Vector force, float DiceHeight) {
        location = location.clone();
        location.subtract(this.location.getPosition());
        location.rotate(new Vector(-this.location.yaw, 0, 0));
    
        float forcefactor = 150 * (DiceHeight - 1);
        float constantforce = 0.0f;
        float pitch = 0;
        float roll = 0;
        float max = 0.48f;
        float min = 0.001f;
        if (location.x < -min && location.x > -max) {
            roll = forcefactor * (force.y + constantforce);
        } else if (location.x > min && location.x < max) {
            roll = -forcefactor * (force.y + constantforce);
        }
        if (location.z < -min && location.z > -max) {
            pitch = forcefactor * (force.y + constantforce);
        } else if (location.z > min && location.z < max) {
            pitch = -forcefactor * (force.y + constantforce);
        }
        this.rotate(0, pitch, roll);
        this.move(force.x, force.y, force.z);
    }
 
    private void doCollisionCheck() {
        java.util.Vector<Vector> collidedpoints = new java.util.Vector<Vector>();
        float lowestpoint = 1;
        float highestpoint = 0;
        for (Vector v : geometry.getRelativePoints(this.location)) {
            //Check for each point of this box if it pierces (is inside) another box
                    
            //Check if any points pierce the terrain
            if (v.y <= 0) {
                 collidedpoints.add(v);
            }
             if (v.y < lowestpoint) lowestpoint = v.y;   
             if (v.y > highestpoint) highestpoint = v.y;
        }
        if (collidedpoints.size() != 0) {
            Vector offsetcenter = Vector.getCenter(collidedpoints);
            //float fallforce = -0.6f * this.velocity.y;
            this.location.y -= lowestpoint;
            float fallforce = 0.5f * (topheight - this.location.y);
            fallforce += 0.09f * (highestpoint - lowestpoint);
            topheight = this.location.y;
            this.velocity.y = 0;
            this.push(offsetcenter, new Vector(this.velocity.x * -0.1f, fallforce, this.velocity.z * -0.1f), highestpoint - lowestpoint);       
            if (fallforce > 0.2f) Resources.s_collide.play(this.location.getPosition());
        }
    }
    public void doLogic(float timefactor) {
        //Do collision detection before or after velocity and location update?
        
        //======================Velocity and location update================
        acceleration.y = -9.81f;
        velocity.x += acceleration.x * timefactor;
        velocity.y += acceleration.y * timefactor;
        velocity.z += acceleration.z * timefactor;
        
        //Air friction move factor
        velocity.x -= 0.2f * velocity.x * timefactor;
        velocity.y -= 0.2f * velocity.y * timefactor;
        velocity.z -= 0.2f * velocity.z * timefactor;
        
        //Air friction rotation factor
        rotation.x -= 0.8f * rotation.x * timefactor;
        rotation.y -= 0.8f * rotation.y * timefactor;
        rotation.z -= 0.8f * rotation.z * timefactor;   
        
        location.x += velocity.x * timefactor;
        location.y += velocity.y * timefactor;
        location.z += velocity.z * timefactor;
        location.yaw += rotation.x * timefactor;
        location.pitch += rotation.y * timefactor;
        location.roll += rotation.z * timefactor;
        if (location.y > topheight) topheight = location.y;
        //=======================================================================
        
        doCollisionCheck();
    }

And I have completely NO idea how to do collisions with other boxes...

Any help on what factors I should take account to properly rotate a box based on an impact collision?

I guess I would have to use the impact direction vector + force, but how can I possible convert this to rotation and velocity changes?

public void applyForce(Vector from, Vector hitat, float force) {
        
    }

EDIT 2

I start to believe I have a way more annoying problem: I can't rotate my geometry in the axis location. At a certain point my geometry can only use yaw or roll, but no pitch.
I use the following transformation parern:

- rotate yaw (+ clockwise, - anti-clockwise)
- rotate pitch (+ forward, - backward)
- rotate roll (+ clockwise, - anti-clockwise