Search found 18 matches

by LastBlow
Thu May 02, 2019 7:57 am
Forum: General Bullet Physics Support and Feedback
Topic: Convex Decomposition Issue with OBJ File
Replies: 1
Views: 376

Re: Convex Decomposition Issue with OBJ File

The second object, the nut, seems to be good candidate for a convex hull object but the first, the virtual hand, is not a convex object because of the fingers and the curling palm and should be loaded as an impact mesh. The impact meshes files have a specific data format in Bullet Physics. Here belo...
by LastBlow
Wed Mar 20, 2019 8:34 pm
Forum: General Bullet Physics Support and Feedback
Topic: change position static object... SOLVED
Replies: 3
Views: 391

Re: change position static object...

For rendering, I happened to be using m_motionState->getWorldTransform(transform) , rather than m_rigidBody->getWorldTransform() . By definition, the motion state for a static object is not updated, so the copy of the world transform in its motion state was apparently not changed when the world tran...
by LastBlow
Wed Mar 20, 2019 4:56 pm
Forum: General Bullet Physics Support and Feedback
Topic: change position static object... SOLVED
Replies: 3
Views: 391

Re: change position static object...

Good to hear from you and know it's possible to move static objects, thank you! In fact, the above code effectively updates the height of all objects but the static ones. The house being a compound object, I just tried with a cylinder: its rendition appeared again under its AABB frame. I had m_dynam...
by LastBlow
Wed Mar 20, 2019 6:17 am
Forum: General Bullet Physics Support and Feedback
Topic: change position static object... SOLVED
Replies: 3
Views: 391

change position static object... SOLVED

Hi, what would be the best way to change the position of a static object , such as a house when the height of the terrain changes without... getting this "out of body experience", see pic? Beside deleting and recreating the static object which obviously works, tried removing, updating the world tran...
by LastBlow
Sat Feb 09, 2019 9:15 am
Forum: General Bullet Physics Support and Feedback
Topic: activate object after size changes...
Replies: 5
Views: 784

Re: activate object after size changes...

Alright, removing the rigid body and adding it back seems to solve the problem for btConvexHullShape which does not get hung in thin air anymore! Thank you for the quick response, Erwin. Curiously, no change thought for btGImpactMeshShape which would still resize their AABB down but not up. Latest ...
by LastBlow
Mon Feb 04, 2019 6:39 pm
Forum: General Bullet Physics Support and Feedback
Topic: activate object after size changes...
Replies: 5
Views: 784

Re: activate object after size changes...

Alright, removing the rigid body and adding it back seems to solve the problem for btConvexHullShape which does not get hung in thin air anymore! Thank you for the quick response, Erwin. Curiously, no change thought for btGImpactMeshShape which would still resize their AABB down but not up... {...} ...
by LastBlow
Sun Feb 03, 2019 5:29 pm
Forum: General Bullet Physics Support and Feedback
Topic: activate object after size changes...
Replies: 5
Views: 784

Re: activate object after size changes...

The mystery thickens, a short video to illustrate the size changes of an impact mesh shape...
which seems to scale AABB just fine down from the initial size but not up.

https://youtu.be/7kAmT3m1Ixc
by LastBlow
Sun Feb 03, 2019 8:42 am
Forum: General Bullet Physics Support and Feedback
Topic: activate object after size changes...
Replies: 5
Views: 784

Re: activate object after size changes...

Thank you very much for your reply! No, I am not using DISABLE_DEACTIVATION or DISABLE_SIMULATION. When resized, boxes, spheres, cylinders and cones behave normally by either working their way out of the terrain if bigger (usually on top but falling through sometimes) or if smaller by falling on the...
by LastBlow
Thu Jan 31, 2019 4:12 pm
Forum: General Bullet Physics Support and Feedback
Topic: activate object after size changes...
Replies: 5
Views: 784

activate object after size changes...

Hey, hey, hey, I change objects sizes and update their collision shapes, then call the method activateAllObjects() but the objects remain hung in thin air, see pic and code here below... The same method activateAllObjects() works fine elsewhere in the project. If I click on and off on the resized ob...
by LastBlow
Thu Jun 21, 2018 8:33 am
Forum: General Bullet Physics Support and Feedback
Topic: [SOLVED] Rotate camera around constraint object...
Replies: 4
Views: 1112

Re: Rotate camera around constraint object...

Right, rotations are always harder than translations... ;-))) Here below the final version - did save the initial transform, then used it to constantly update the basis of the constraint. Only, make sure there are no other constraints on y, so the object can be rotated around y to face the camera: r...
by LastBlow
Sat Jun 16, 2018 9:49 am
Forum: General Bullet Physics Support and Feedback
Topic: [SOLVED] Rotate camera around constraint object...
Replies: 4
Views: 1112

Re: Rotate camera around constraint object...

Thank you for the reply! ;-))) Yes, there is a constraint applied to the object, so it can be carried around like it was held in a hand while walking and turning around. Did add the line here below to account for the camera rotation. The object now faces the camera but jerks when grabbed because its...
by LastBlow
Tue Jun 12, 2018 10:41 pm
Forum: General Bullet Physics Support and Feedback
Topic: [SOLVED] Rotate camera around constraint object...
Replies: 4
Views: 1112

[SOLVED] Rotate camera around constraint object...

Wanted to ask here while I am trying to figure it out by myself... ;-))) I am rotating the camera around an object with a constraint applied on it, like when you would turn on yourself while holding an object which would then constantly present the same face to you. Only, despite the constraint, the...
by LastBlow
Sun Nov 12, 2017 3:15 am
Forum: General Bullet Physics Support and Feedback
Topic: [SOLVED] texture support in Bullet Physics...
Replies: 2
Views: 2111

Re: texture support in Bullet Physics...

Oh, I sure asked this (totally newbie) question more than an year ago...

Thank you for taking the time to answer, it all make sense now. In fact, I use OpenGL and Blender for visualization.
Will go ahead and mark the question solved.
by LastBlow
Sun Nov 12, 2017 1:47 am
Forum: General Bullet Physics Support and Feedback
Topic: [SOLVED] btGImpactMeshShape scrambled...
Replies: 1
Views: 1414

Re: btGImpactMeshShape scrambled...

Alright, just figured it out, so it can help others... Blender names its indices starting at 1 while Bullet Physics starts at 0. As an example, here below how the vertices and indices for a btTriangleIndexVertexArray should look like for a cube mesh exported from Blender to render properly in Bullet...
by LastBlow
Sun Nov 12, 2017 1:29 am
Forum: General Bullet Physics Support and Feedback
Topic: How do I properly use a TriangleIndexVertexArray?
Replies: 4
Views: 1768

Re: How do I properly use a TriangleIndexVertexArray?

The point is that Blender names the vertices starting at 1 while Bullet Physics starts at 0. Here below another example, the cube mesh. const int NUMBER_VERTICES = 8; const int NUMBER_TRIANGLES = 12; static float bunnyVertices[NUMBER_VERTICES * 3] = { 1.000000, -1.000000, -1.000000, 1.000000, -1.000...