## Search found 26 matches

Sat Aug 05, 2017 3:59 pm
Forum: General Bullet Physics Support and Feedback
Topic: Mesh pivot y at zero
Replies: 0
Views: 1544

### Mesh pivot y at zero

When building a btBoxShape out of a mesh that has the pivot on the ground (y at zero), the mesh's bounding volume and half way undernearth the mesh to half way in the middle of the mesh itself, when resolving physics, it will fall thru all static objects. How is it possible to build the box that emb...
Mon Apr 10, 2017 3:36 am
Forum: General Bullet Physics Support and Feedback
Topic: Getting the amount of repulsion during collision detected
Replies: 0
Views: 1675

### Getting the amount of repulsion during collision detected

The physics component is one of the many components in my simulation. But at least for this moment, the order of execution is not explicitly defined. So the setWorldTransform called during each frame can be overridden by the other components. My thought was to just get the amount of distance the phy...
Mon Jan 04, 2016 5:09 am
Forum: General Bullet Physics Support and Feedback
Topic: btBoxShape and mesh pivot point question
Replies: 0
Views: 2840

### btBoxShape and mesh pivot point question

// pivot point on ground, so wrong // it is right if pivot point is at center btBoxShape *shape = new btBoxShape(btVector3(width / 2.0f, height / 2.0f, length / 2.0f)); How can I make the mesh not falling off when the pivot point of the mesh is on the ground rather than in the center of the mesh? I...
Sun Dec 27, 2015 8:28 am
Forum: General Bullet Physics Support and Feedback
Topic: Both Ground and Agents have world transformations at y zero.
Replies: 0
Views: 2673

### Both Ground and Agents have world transformations at y zero.

The initial positions of the human characters are at y zero. And the ground as well. When I start my simulation, The characters straight off fall down to the endless bottom. Should I raise the human positions up a bit? However I don't want to do that frankly because the agents should be positioned p...
Thu Jan 15, 2015 7:27 am
Forum: General Bullet Physics Support and Feedback
Topic: Rigid bodies penetrate the ground
Replies: 0
Views: 2138

### Rigid bodies penetrate the ground

void Physics::addStaticMesh(CObjects* pObj) { m_pObj = pObj; D3DXVECTOR3 vMin, vMax; pObj->m_Mesh->GetBoundingBox(vMin, vMax); float width = vMax.x - vMin.x; float length = vMax.y - vMin.y; float height = vMax.z - vMin.z; btBoxShape *shape = new btBoxShape(btVector3(width / 2.0f, length / 2.0f, hei...
Thu Jan 15, 2015 6:12 am
Forum: General Bullet Physics Support and Feedback
Topic: What is the best practice to exchange transforms?
Replies: 7
Views: 3884

### Re: What is the best practice to exchange transforms?

Hi there,
Thanks
It works now.
But the returned rotations are a bit annoying, which are very close to 0
and accumulating and then those small values get enlarged that would make objects spin around vigorously...
Thanks
Jack
Wed Jan 14, 2015 8:02 am
Forum: General Bullet Physics Support and Feedback
Topic: What is the best practice to exchange transforms?
Replies: 7
Views: 3884

### Re: What is the best practice to exchange transforms?

Update: I finally decided to update the object's transform first, next update the physics engine, But when I debug the final transform at the render method, I find the world transformations finally shrank back to a very small value. Update2: Got a small problem, just don't know why when I pass in th...
Wed Jan 14, 2015 5:33 am
Forum: General Bullet Physics Support and Feedback
Topic: What is the best practice to exchange transforms?
Replies: 7
Views: 3884

### Re: What is the best practice to exchange transforms?

The way I would do it: give the MotionState a btTransform data member that you can update and implement MotionState::getWorldTransform() to apply it. Hello, Here is what I am doing during a frame render. I've set the motion state to identity (locally). I don't know, I've used back the btDefaultMoti...
Tue Jan 13, 2015 12:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: What is the best practice to exchange transforms?
Replies: 7
Views: 3884

### What is the best practice to exchange transforms?

From the GameObject class, I've got a world transformation variable. So that I can SetRot and SetPos of it at any time any where. Now that I have added in a physics variable. It's got a motion state in it I reckon these transformations are incremental. Should I keep a variable to track the motion st...
Tue Jan 13, 2015 8:18 am
Forum: General Bullet Physics Support and Feedback
Topic: btConvexTriangleMeshShape
Replies: 2
Views: 1955

### btConvexTriangleMeshShape

I am wondering which shapes to use for dynamic triangular meshes. which has a motion state and affected by gravity. I originally used btBvhTriangleMeshShape But at runtime, it says it doesn't support dynamics. So I switched to btConvexTriangleMeshShape But it crashes at calculateLocalInertia inline ...
Mon Jan 12, 2015 12:50 pm
Forum: General Bullet Physics Support and Feedback
Topic: ID3DXMesh or D3DXFRAME Hierarchy to collision shapes
Replies: 0
Views: 2072

### ID3DXMesh or D3DXFRAME Hierarchy to collision shapes

I am currently making an application which uses bullet as the physics engine. I am wondering how I can pass a ID3DXMesh or Frame Hierarchy to bullet as a parameter so that the collision shapes creation process can be automated. I am sure someone has implemented that before and hope that he/she may g...
Thu Nov 06, 2014 9:55 am
Forum: General Bullet Physics Support and Feedback
Topic: How to specify a btBoxShape's transformation?
Replies: 6
Views: 3837

### Re: How to specify a btBoxShape's transformation?

Okay, thank you then, let me take some read on the documentation first.
Thanks
Jack
Thu Nov 06, 2014 5:10 am
Forum: General Bullet Physics Support and Feedback
Topic: How to specify a btBoxShape's transformation?
Replies: 6
Views: 3837

### Re: How to specify a btBoxShape's transformation?

Hi there,
Can I just create a shape without attaching any collision object to it, I need it for cooperative pathfinding
as a placeholder...
Thanks
Jack
Wed Nov 05, 2014 12:30 pm
Forum: General Bullet Physics Support and Feedback
Topic: How to specify a btBoxShape's transformation?
Replies: 6
Views: 3837

### How to specify a btBoxShape's transformation?

I want to define a box shape that has a position, probably an orientation...
How can I achieve this?
Thanks
Jack
Wed Nov 05, 2014 10:14 am
Forum: General Bullet Physics Support and Feedback
Topic: How to make ogre static entities eternally impassible?
Replies: 0
Views: 2805

### How to make ogre static entities eternally impassible?

I don't want to let the "infrastructure" be bumped off from where it is sitting.
Just some game agents are allowed to be affected by bullet, how can I achieve this?
Thanks
Jack