Search found 456 matches

by Flix
Thu Sep 18, 2014 7:17 am
Forum: Physics authoring tools, serialization, standards and related topics
Topic: Convex Decomposition with HACD in Blender
Replies: 1
Views: 7559

Re: Convex Decomposition with HACD in Blender

I'm not an Python or a Blender expert at all, so I don't know what's going on (maybe it's something I've messed up myself). However following your instructions (python setup.py install --install-lib=~/.config/blender/2.71/scripts/addons/), everything seems to work, until I try to enable the addon in...
by Flix
Sun Aug 17, 2014 10:09 am
Forum: General Bullet Physics Support and Feedback
Topic: Vehicle demo attaching camera problem.
Replies: 2
Views: 2676

Re: Vehicle demo attaching camera problem.

I think that's just a matter of conventions. I've read on some other forum some time ago that the "correct" way to map all the bodies in OpenGL should be with Y up and -Z forward, since this convention can be used for both the camera and the other objects. I don't remember what convention Bullet use...
by Flix
Fri Jun 13, 2014 11:11 am
Forum: General Bullet Physics Support and Feedback
Topic: No Collisions Between Mesh and KinematicCharacterController
Replies: 4
Views: 3344

Re: No Collisions Between Mesh and KinematicCharacterControl

The Bullet official character demo loads a a level (.bsp extension as far as I remember) and converts it to a series of btConvexHullShapes. I don't know why you can't run it, but this is not very important as far as I can understand, since you're using a btBvhTriangleMeshShape as a background (this ...
by Flix
Sat May 24, 2014 8:54 am
Forum: General Bullet Physics Support and Feedback
Topic: Apply force to a child in a btCompoundShape?
Replies: 2
Views: 2726

Re: Apply force to a child in a btCompoundShape?

I want to apply a specific force to just one of the child shapes. Is that possible? Nope, compound shapes have been designed mainly to simulate moving concave bodies (and they're commonly used to shift the rigid bodies' center of mass too). Some people use them to attach/detach child shapes at runt...
by Flix
Sat May 17, 2014 9:17 am
Forum: General Bullet Physics Support and Feedback
Topic: Filtering CompoundCompound collision contact points.
Replies: 4
Views: 3816

Re: Filtering CompoundCompound collision contact points.

The collision that occurs looks good, but the problem is that I am still having 100 different contact pairs passed for two compound objects colliding. Having your physics solver do 100 contacts for a single shape is a pretty hefty price in performance, which is my main concern. Yes, I know, using c...
by Flix
Fri May 16, 2014 11:02 am
Forum: General Bullet Physics Support and Feedback
Topic: Filtering CompoundCompound collision contact points.
Replies: 4
Views: 3816

Re: Filtering CompoundCompound collision contact points.

Is there no built-in bullet method to prevent btCompoundShapes ConvexChildren from interacting with each other in such a manner? Are there any well known ways of dealing with filtering contact points? First of all, I've used compounds of convex hull shapes quite frequently in the past, and I never ...
by Flix
Thu Apr 17, 2014 9:05 am
Forum: General Bullet Physics Support and Feedback
Topic: RayTest simple issue
Replies: 4
Views: 2593

Re: RayTest simple issue

I don't get the point of setting an identity matrix as the object transform. I am doing something wrong in my code? btQuaternion(0.f, 0.f, 0.f, 0.f) doesn't seem to be a normalized unit quaternion. I would have used something like: collisionObject->setWorldTransform(btTransform(btMatrix3x3::getIden...
by Flix
Wed Apr 16, 2014 9:11 am
Forum: General Bullet Physics Support and Feedback
Topic: MultiBody (Featherstone) - Setting damping
Replies: 3
Views: 3815

Re: MultiBody (Featherstone) - Setting damping

New issue -- Maybe the damping was there for a reason? Now my model quickly gains energy and spins out of control. It seems that the damping was a hack to keep things stable. Any ideas about a real fix that doesn't involve arbitrary damping? Well, I don't have enough experience with the Featherston...
by Flix
Wed Apr 16, 2014 8:50 am
Forum: General Bullet Physics Support and Feedback
Topic: RayTest simple issue
Replies: 4
Views: 2593

Re: RayTest simple issue

GripInc wrote:collisionObject->setWorldTransform(btTransform(btQuaternion(0.f, 0.f, 0.f, 0.f), btVector3(100.f,0.f,0.f)));
What world transform is this ? Maybe you should use btMatrix3x3::getIdentity() as the transform basis.
by Flix
Tue Apr 15, 2014 10:55 am
Forum: General Bullet Physics Support and Feedback
Topic: MultiBody (Featherstone) - Setting damping
Replies: 3
Views: 3815

Re: MultiBody (Featherstone) - Setting damping

Well, I've never used that class so far, and m_linearDamping and m_angularDamping seem to be private. However there are some accessors: btScalar getLinearDamping() const { return m_linearDamping; } void setLinearDamping( btScalar damp) { m_linearDamping = damp; } btScalar getAngularDamping() const {...
by Flix
Tue Apr 08, 2014 10:18 am
Forum: General Bullet Physics Support and Feedback
Topic: Modeling a train using joints & a number of raycast vehicles
Replies: 32
Views: 19050

Re: Modeling a train using joints & a number of raycast vehi

I purpose stopped the Loco, because at higher speed you can't see the wheels how good turning. ;-) Good to know, so everything seems to work as expected :) . Furthermore, if you're using the default btRaycastVechicle, that means that 'ray-wheels' with different directions are working nice, and this...
by Flix
Mon Apr 07, 2014 9:18 am
Forum: General Bullet Physics Support and Feedback
Topic: Modeling a train using joints & a number of raycast vehicles
Replies: 32
Views: 19050

Re: Modeling a train using joints & a number of raycast vehi

When I add a wheel to the Vehicle, why is important it is a frontwheel or not? This is not so obvious by trains. Well, I've not been using btRaycastVehicles for some time, but as far as I can remember the wheels marked as 'front' are the ones that can be used for steering the vehicle. I don't know ...
by Flix
Thu Apr 03, 2014 9:04 am
Forum: General Bullet Physics Support and Feedback
Topic: Modeling a train using joints & a number of raycast vehicles
Replies: 32
Views: 19050

Re: Modeling a train using joints & a number of raycast vehi

Adding orthogonal ray tests to trap the train onto the track is an interesting approach indeed :D. Thanks for sharing the details :P !
by Flix
Wed Mar 26, 2014 9:21 am
Forum: General Bullet Physics Support and Feedback
Topic: Moving rigid bodies with setLinearvelocity
Replies: 1
Views: 5762

Re: Moving rigid bodies with setLinearvelocity

You might need to call body->activate() before setting the linear velocity, or you can just forget about it, by setting the DISABLE_DEACTIVATION state.
by Flix
Wed Mar 12, 2014 10:05 am
Forum: General Bullet Physics Support and Feedback
Topic: Lots of static bodies
Replies: 3
Views: 3005

Re: Lots of static bodies

now what I do is join all the meshes (with a tool), export the obj, import it to Blender and then export the .bullet to load it later with the Bullet worldimporter. So, I think the only solution to my problem is to reduce the resolution of the mesh (.obj) by removing inner geometry, using the modif...