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# irlanrobson

Member Since 08 May 2012
Offline Last Active May 23 2013 02:50 PM

### In Topic: What are the benefits of the TOI?

04 April 2013 - 09:39 AM

e.g:

I have a sphere-plane intersection.

The velocity.dot(plane.normal) (relative velocity along the plane normal = velocity + angular velocity.cross(relative point) ) is oscilating between 0 - 0.15 and I want to apply static friction when Vrn == 0. The TOI could fix this?

What do you mean with TOI?

Time Of Impact

### In Topic: OBB plane point of intersection

26 February 2013 - 07:29 AM

I'm calculating like this and is giving me realistic results:

Taking all the vertices combinations (total = 24 lines = 48 points) on the OBB, doing a Ray-Plane Intersection and getting the intersection point.
There is some kind of better way to do this or it is actually the right way? Thanks.

### In Topic: Oriented Bounding Box (rotating about the central point)

20 February 2013 - 07:07 AM

min = 0, 0, 0
max = 2, 2, 2

### In Topic: Oriented Bounding Box (rotating about the central point)

19 February 2013 - 08:05 AM

Now seems to REALLY rotate about the world center  . I think the first try it's more correct. When I draw a cube like this:

glBegin(GL_POLYGON);
glColor3f( 1.0, 1.0, 1.0 );
glVertex3f( 0.5, -0.5, 0.5 );
glVertex3f( 0.5, 0.5, 0.5 );
glVertex3f( -0.5, 0.5, 0.5 );
glVertex3f( -0.5, -0.5, 0.5 );
glEnd();

// Purple side - RIGHT
glBegin(GL_POLYGON);
glColor3f( 1.0, 0.0, 1.0 );
glVertex3f( 0.5, -0.5, -0.5 );
glVertex3f( 0.5, 0.5, -0.5 );
glVertex3f( 0.5, 0.5, 0.5 );
glVertex3f( 0.5, -0.5, 0.5 );
glEnd();

// Green side - LEFT
glBegin(GL_POLYGON);
glColor3f( 0.0, 1.0, 0.0 );
glVertex3f( -0.5, -0.5, 0.5 );
glVertex3f( -0.5, 0.5, 0.5 );
glVertex3f( -0.5, 0.5, -0.5 );
glVertex3f( -0.5, -0.5, -0.5 );
glEnd();

// Blue side - TOP
glBegin(GL_POLYGON);
glColor3f( 0.0, 0.0, 1.0 );
glVertex3f( 0.5, 0.5, 0.5 );
glVertex3f( 0.5, 0.5, -0.5 );
glVertex3f( -0.5, 0.5, -0.5 );
glVertex3f( -0.5, 0.5, 0.5 );
glEnd();

// Red side - BOTTOM
glBegin(GL_POLYGON);
glColor3f( 1.0, 0.0, 0.0 );
glVertex3f( 0.5, -0.5, -0.5 );
glVertex3f( 0.5, -0.5, 0.5 );
glVertex3f( -0.5, -0.5, 0.5 );
glVertex3f( -0.5, -0.5, -0.5 );
glEnd();

Rotates perfectly. Maybe is a problem with max and min and I can't figure out. If someone know how to correctly draw a OBB...

### In Topic: Sphere Physics Simulation 3D (Impulse Based Reaction)

14 February 2013 - 10:41 AM

hm i saw in another topic that angular momentum can be expressed by

dL = r x J (where J is the impulse vector) and r the position of the sphere...

thanks anyway... here is the topic if someone get interested

http://www.gamedev.net/topic/465248-calculating-impulse-due-to-rigid-body-collision-with-friction/

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