Search found 11 matches

by jcrada
Thu Sep 30, 2010 4:12 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Evolution of Morphology and Behavior of Virtual Creatures
Replies: 0
Views: 4679

Evolution of Morphology and Behavior of Virtual Creatures

Hi, this was my master thesis. Evolution of Morphology and Behavior of Virtual Creatures: A model based on Swarm Intelligence and Artificial Neural Networks. ABSTRACT: In this paper, simultaneous evolution of morphology and behavior of virtual creatures takes place in a virtual world physically real...
by jcrada
Thu Sep 30, 2010 3:27 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Simulation of Underwater Virtual World
Replies: 0
Views: 1851

Simulation of Underwater Virtual World

Hi all,

Is there a way that I could simulate an underwater virtual world? At first I thought I could simulate it changing the gravity, but is there a more "natural" way to achieve this? It is important as well to be able to simulate underwater currents.

Any suggestions?


Regards,

Juan
by jcrada
Thu Apr 30, 2009 5:22 am
Forum: General Bullet Physics Support and Feedback
Topic: Temporarily disabling a RigidBody
Replies: 2
Views: 2290

Re: Temporarily disabling a RigidBody

Hi,

I would try

Code: Select all

getRigidBody()->setActivationState(DISABLE_SIMULATION);
but I think that you have do the same to all the other rigid bodies it is connected to. I think that is called an island, so you must disable the whole island.

DISABLE_SIMULATION is defined in btCollisionObject.
by jcrada
Mon Apr 27, 2009 1:39 am
Forum: General Bullet Physics Support and Feedback
Topic: Quaternion's values...
Replies: 1
Views: 2046

Quaternion's values...

Hi, I need to know the maximum and minimum values of w,x,y,z of each rigid body's quaternion. I believe that they are in [0,1), but I am not sure. Is there a way to find that out? For example, what is the max and min expected output for "some_body" at any position from the following code: btTransfor...
by jcrada
Fri Apr 17, 2009 6:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: btHingeConstraint Limits...
Replies: 1
Views: 1505

btHingeConstraint Limits...

Hi,
In what range are the limits of a btHingeConstraint? Which is the lower limit? Which is the upper limit? Does it goes from [0,2PI] ? Or from [-PI/2,PI/2]? Or does it depends on something else? I need the lowest and the highest limit a hinge can have.

Thanks all :)
by jcrada
Fri Apr 17, 2009 7:13 am
Forum: General Bullet Physics Support and Feedback
Topic: Bullet simulation's erratic behavior... Help Please!
Replies: 2
Views: 1491

Re: Bullet simulation's erratic behavior... Help Please!

Thank you very much for your quick reply. I will reproduce this behavior in Bullet's Demo as soon as I have the chance. For the moment, I decided to use the other constraints instead, btHingeConstraint, btPoint2PointConstraint, and btConeTwistConstraint. They will do the job in such a hurry. As soon...
by jcrada
Fri Apr 17, 2009 12:07 am
Forum: General Bullet Physics Support and Feedback
Topic: Bullet simulation's erratic behavior... Help Please!
Replies: 2
Views: 1491

Bullet simulation's erratic behavior... Help Please!

Hi, I am having problems with bullet's simulation of rigid bodies. An example of this behavior may be found at http://www.youtube.com/watch?v=fREpAAth-wc . I have created a creature of three rigid bodies and two btGeneric6DOFConstraint's. The constraint limits are: lower=[0.75 * -M_PI ; 0.75 * -M_PI...
by jcrada
Wed Jan 21, 2009 3:24 am
Forum: General Bullet Physics Support and Feedback
Topic: Joint Torque...
Replies: 4
Views: 4328

Re: Joint Torque...

Thank you very much! You have been of great help! I am using btGeneric6DofConstraint and it does have a btRotationalMotorLimit, but it is not behaving as I wish it would. In fact, it is not behaving at all. Do you know where can I find examples or help on how to use motors? Is it just enabling it an...
by jcrada
Sun Jan 18, 2009 10:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: Joint Torque...
Replies: 4
Views: 4328

Joint Torque...

Hi, I have been looking all over the forum to find a way to apply torque at a joint. I am building a robotics simulation with a ragdoll and I really need to apply torque at its joints in order to make it move. Given what I have seen, Bullet only offers me to apply torque at the center of mass. Howev...
by jcrada
Thu Nov 06, 2008 2:13 pm
Forum: General Bullet Physics Support and Feedback
Topic: Avoid penetration's severe reaction
Replies: 1
Views: 2720

Re: Avoid penetration's severe reaction

Hi. After many experiments I have reach the conclusion that the problem is the angular limits in axis Y. Using the following code makes the simulation run smooth for me. I found no problem having [-M_PI_2, M_PI_2] as angular limits in axis X and Z. g6dof->setAngularLowerLimit(btVector3(0, (2.0 / 3.0...
by jcrada
Fri Oct 24, 2008 6:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: Avoid penetration's severe reaction
Replies: 1
Views: 2720

Avoid penetration's severe reaction

Hi, I am creating a ragdoll following the RagdollDemo but I am encountering some difficulties related to penetration reaction. For example, I am using a btGeneric6DofJoint for the shoulder joint with angular limits that make the upperarm penetrate the spine when these values are very low or very hig...