Search found 73 matches

by Ehsanizadi
Wed Jan 06, 2021 1:52 pm
Forum: General Bullet Physics Support and Feedback
Topic: point to point spring constraint possible?
Replies: 6
Views: 6924

Re: point to point spring constraint possible?

Hi, does btGeneric6DofSpringConstraint support point to point spring constraint when two dynamic objects are moving with respect to each other? I see that for btGeneric6DofSpringConstraint, spring and damping coefficients can be defined only in 3 directions, which means, if the location of two conne...
by Ehsanizadi
Wed Jan 06, 2021 1:47 pm
Forum: General Bullet Physics Support and Feedback
Topic: Spring between two dynamic objects
Replies: 2
Views: 2206

Re: Spring between two dynamic objects

Hi there, I am exactly looking for the same thing. I did not find a point to point spring feature, however, a workaround might be to dynamically adjust the stiffness and damping of the point to point object at each time step when the orientation of the two dynamic bodies are altered. BTW if you foun...
by Ehsanizadi
Wed Feb 15, 2017 7:09 pm
Forum: General Bullet Physics Support and Feedback
Topic: Serialization of Softbodies
Replies: 1
Views: 2235

Serialization of Softbodies

Hi,

In the code it is mentioned that for the serialization of softbodies, refer to the derialzation demo, however, I cannot find such demo anymore,
Can some body give some hints for serialization of softbofies and how to import it into the world and how to access to the nodes and links?

Thanks
Ehsan
by Ehsanizadi
Wed Jan 18, 2017 1:15 pm
Forum: General Bullet Physics Support and Feedback
Topic: define local coordinates for btGeneric6DofSpring2Constraint
Replies: 1
Views: 2193

define local coordinates for btGeneric6DofSpring2Constraint

Hi, I want to define a spring between two rigid bodies (one static and one dynamic). However, I want the axis of the spring to be rotated along the line connecting both rigid bodies. In this way, the spring stiffness will remain valid regardless of the rotation of the dynamic rigid body. Does anyone...
by Ehsanizadi
Tue Nov 15, 2016 1:57 pm
Forum: General Bullet Physics Support and Feedback
Topic: deformation diffusion in softbody
Replies: 1
Views: 2186

Re: deformation diffusion in softbody

Take a look at this for more clarification:
https://youtu.be/79WKvHVGRMw
by Ehsanizadi
Tue Nov 15, 2016 1:48 pm
Forum: General Bullet Physics Support and Feedback
Topic: deformation diffusion in softbody
Replies: 1
Views: 2186

deformation diffusion in softbody

Hi, If you model a cloth or a rope, and clip one end, and apply a force at the end of that, in order to stretch it (for simplicity under zero gravity), you will notice that the elongation of the nodes around the clipped nodes are higher than the elongation of the nodes around the area on which the f...
by Ehsanizadi
Thu Aug 18, 2016 9:41 pm
Forum: General Bullet Physics Support and Feedback
Topic: SoftBody behaviour with time increment and iteration number
Replies: 3
Views: 3824

Re: SoftBody behaviour with time increment and iteration num

With such annoying things of softbodies, perhaps it is best to use FEM for modelling of deformable bodies for engineering usages.
However, it is not yet implemented in Bullet... :(
by Ehsanizadi
Wed Aug 17, 2016 8:38 am
Forum: General Bullet Physics Support and Feedback
Topic: SoftBody behaviour with time increment and iteration number
Replies: 3
Views: 3824

SoftBody behaviour with time increment and iteration number

Hi all, I'm simulating a rope (softbody) as an spring in an engineering project. However, I found out that soft body (not even ropes, but patches) behave strangely with time step and iteration! Ok, I understand that the behaviour should change when iteration number is changed, but it must converge t...
by Ehsanizadi
Sun Apr 03, 2016 1:48 pm
Forum: Non-technical forum and license/patent discussion
Topic: Stiff softbody
Replies: 0
Views: 12246

Stiff softbody

Hi, In one of my engineering simulations I need to model a very stiff soft body, However, the limit for the linear stiffness of soft body is limited to 1. What do you suggest? two possible options crossed my mind: 1) Scale the forces applied to the soft body down, so, such scaling needs to be applie...
by Ehsanizadi
Wed Mar 16, 2016 11:33 am
Forum: General Bullet Physics Support and Feedback
Topic: Get vertex of btGImpactMeshShape
Replies: 2
Views: 3103

Re: Get vertex of btGImpactMeshShape

Is it something related to locking or unlocking the mesh?

Any hints?
by Ehsanizadi
Wed Mar 09, 2016 3:22 pm
Forum: General Bullet Physics Support and Feedback
Topic: Get vertex of btGImpactMeshShape
Replies: 2
Views: 3103

Get vertex of btGImpactMeshShape

Hi,

How can I get vertices of a gimpact shape?

I do:

btVector3 localPos;
collisionShape->getMeshPart(0)->getVertex(j,localPos);

it compiles well, but when it executes, it gives a segmentation fault!

Am I missing something?

Regards,
Ehsan
by Ehsanizadi
Mon Feb 29, 2016 8:51 am
Forum: General Bullet Physics Support and Feedback
Topic: Linking order of soft body and bullet world importer
Replies: 2
Views: 3366

Re: Linking order of soft body and bullet world importer

Sorry
It was my mistake!

there is no "lib" folder in bullet 3 any more.
by Ehsanizadi
Mon Feb 15, 2016 11:26 am
Forum: General Bullet Physics Support and Feedback
Topic: Linking order of soft body and bullet world importer
Replies: 2
Views: 3366

Re: Linking order of soft body and bullet world importer

Now i figure out that for exporting and importing of softRigidDynamicsWorld s I get always the above error!

It is strange. In the bullet serialization wiki page, it is noted that serialization supports softbodies, but it seems doesn't.

Any hint?
by Ehsanizadi
Mon Feb 15, 2016 10:43 am
Forum: General Bullet Physics Support and Feedback
Topic: Linking order of soft body and bullet world importer
Replies: 2
Views: 3366

Linking order of soft body and bullet world importer

Hi, I have a discrete dynamics world and I exported that in a "saveWorld.bullet" file. It includes hundreds of rigid bodies. Then I want to import this world and add some soft bodies to the world to interact with the rigid bodies in the imported rigid bodies. However, I cannot figure out h...