Search found 41 matches

by erbisme4@yahoo.com
Thu Aug 10, 2017 2:06 pm
Forum: General Bullet Physics Support and Feedback
Topic: I want to know if i'm picking front face or back face
Replies: 4
Views: 5730

Re: I want to know if i'm picking front face or back face

I'm not sure what you mean. btTriangleIndexVertexArray::addIndexedMesh ? A pool of vertices with child meshes? What exact bullet structure are you talking about?
by erbisme4@yahoo.com
Tue Aug 08, 2017 5:39 pm
Forum: General Bullet Physics Support and Feedback
Topic: I want to know if i'm picking front face or back face
Replies: 4
Views: 5730

Re: I want to know if i'm picking front face or back face

Also the ClosestRayResultCallback will always yield the front plane if I'm correct.
by erbisme4@yahoo.com
Tue Aug 08, 2017 5:32 pm
Forum: General Bullet Physics Support and Feedback
Topic: I want to know if i'm picking front face or back face
Replies: 4
Views: 5730

Re: I want to know if i'm picking front face or back face

check the hit normal and take the dot product with the camera. If it's negative it's the side closest to you.
by erbisme4@yahoo.com
Thu Jun 22, 2017 3:52 pm
Forum: General Bullet Physics Support and Feedback
Topic: btConvexHullShape vs btConvexTriangleMeshShape
Replies: 1
Views: 3114

Re: btConvexHullShape vs btConvexTriangleMeshShape

Code: Select all

convexHullShape->initializePolyhedralFeatures();
by erbisme4@yahoo.com
Mon Jun 19, 2017 2:12 pm
Forum: General Bullet Physics Support and Feedback
Topic: looking for working code to create btGImpactMeshShape
Replies: 1
Views: 3418

Re: looking for working code to create btGImpactMeshShape

Please make sure you actually register the GImpact collision algorithm.

Code: Select all

btCollisionDispatcher *dispatcher = static_cast<btCollisionDispatcher *>(m_pDynamicsWorld->getDispatcher());
    btGImpactCollisionAlgorithm::registerAlgorithm(dispatcher);
by erbisme4@yahoo.com
Tue Jun 06, 2017 1:22 pm
Forum: General Bullet Physics Support and Feedback
Topic: How to rotate a body (and connected ones) instantly?
Replies: 1
Views: 3025

Re: How to rotate a body (and connected ones) instantly?

You can write your own method that takes in a transform and individually transforms each body connected through the constraints. This is like teleporting, so it's not recommended.
by erbisme4@yahoo.com
Thu May 11, 2017 1:50 pm
Forum: General Bullet Physics Support and Feedback
Topic: LocalScaling not applied on RigidBody
Replies: 1
Views: 3386

Re: LocalScaling not applied on RigidBody

You scaled the rigid body but your graphical representation still isn't accurate.
by erbisme4@yahoo.com
Wed May 10, 2017 1:55 pm
Forum: General Bullet Physics Support and Feedback
Topic: Graphical mesh lag behind collision shape in DebugDraw
Replies: 1
Views: 3686

Re: Graphical mesh lag behind collision shape in DebugDraw

This is natural as you update the graphical representation of the cube from the actual rigid body.
by erbisme4@yahoo.com
Fri May 05, 2017 7:17 pm
Forum: General Bullet Physics Support and Feedback
Topic: GImpact-GImpact bodies not colliding [resolved]
Replies: 4
Views: 5175

Re: GImpact-GImpact bodies not colliding [resolved]

Let me know how that goes for you. I had some pretty awful experiences with GImpact shapes, where they would get sucked into each other when near, as well as penetration issues.
by erbisme4@yahoo.com
Fri May 05, 2017 1:42 pm
Forum: General Bullet Physics Support and Feedback
Topic: GImpact-GImpact bodies not colliding [resolved]
Replies: 4
Views: 5175

Re: GImpact-GImpact bodies not colliding (robotics applicati

Did you register the GIMPACT collision algorithm?

Code: Select all

btCollisionDispatcher * dispatcher = static_cast<btCollisionDispatcher *>(m_pDynamicsWorld->getDispatcher());
btGImpactCollisionAlgorithm::registerAlgorithm(dispatcher);
by erbisme4@yahoo.com
Wed Apr 26, 2017 2:52 am
Forum: General Bullet Physics Support and Feedback
Topic: Calculate volume for convex shapes?
Replies: 2
Views: 4262

Re: Calculate volume for convex shapes?

As a guestimate you could try the bbox as well as the bounding sphere for an approximation.
by erbisme4@yahoo.com
Mon Apr 24, 2017 1:48 pm
Forum: General Bullet Physics Support and Feedback
Topic: Drawing a rigid body's path?
Replies: 1
Views: 4016

Re: Drawing a rigid body's path?

You can probably fake the trajectory line using a linear spline. Get the rigidBody position at time(n), and time(n+1) and that is your endpoints for your line. glBegin(GL_LINES); glColor3f(1.0f, 0.0f, 0.0f); //red glVertex3f(0.0f, 0.0f, 0.0f); //origin glVertex3f(0.0f, 0.0f, 1.0f); //bullet fired st...
by erbisme4@yahoo.com
Fri Apr 14, 2017 2:32 pm
Forum: General Bullet Physics Support and Feedback
Topic: Updating mesh position based on rigidBody position?
Replies: 9
Views: 13037

Re: Updating mesh position based on rigidBody position?

I'm not sure what you mean by you can see the physics object moving before and the graphics following? Are you talking about the debug drawing that bullet does? Sounds to me like the physics object is rendered first, followed by your graphics object.
by erbisme4@yahoo.com
Thu Apr 13, 2017 9:42 pm
Forum: General Bullet Physics Support and Feedback
Topic: Help with using contactPairTest() and ContactResultCallback?
Replies: 6
Views: 8405

Re: Help with using contactPairTest() and ContactResultCallb

I can't tell for sure without looking at your code, but maybe instead of using ContactPairTest, which may be expensive(i'm not sure, haven't really used it much) use a btInternalTickCallback which will get called by InternalSingleStepSimulation. In the callback you can iterate over all the collision...