Search found 55 matches

by kloplop321
Fri Apr 13, 2012 4:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: Monowheel - Angular Velocity or Raycast?
Replies: 3
Views: 2216

Re: Monowheel - Angular Velocity or Raycast?

If you really want to be physically based, use tangential forces. But, if you want something stable that you can depend on, use angular velocities for spinning and modify the spacial velocities yourself as well. But, does it really have to be in multiple parts? If you're making a game, you only need...
by kloplop321
Mon Mar 19, 2012 2:20 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Counter strike recoil feel
Replies: 2
Views: 6623

Re: Counter strike recoil feel

The player isn't actually moving, its all just an aim and camera effect.

No real forces are involved in this.

It looks like simple noise and pull-up with the gun.
by kloplop321
Sun Mar 04, 2012 3:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: callback when body falls in sleep
Replies: 2
Views: 878

Re: callback when body falls in sleep

You can edit the source code for that.
You should only need to edit two functions that would call the callback, and add a function which adds a callback pointer on rigid body or collision object.

Be aware though that if the callback pointer goes bad, you'll have a segfault.
by kloplop321
Thu Feb 23, 2012 7:39 pm
Forum: General Bullet Physics Support and Feedback
Topic: Timestep and erp
Replies: 1
Views: 1188

Re: Timestep and erp

Could you provide a recorded example showing the problem in action?
That and or plotted data showing the differences?
by kloplop321
Thu Feb 23, 2012 1:14 am
Forum: General Bullet Physics Support and Feedback
Topic: Automated flying object
Replies: 4
Views: 1661

Re: Automated flying object

Negating gravity is simply nullifying its effects, which arithmetically would be adding the opposite vector of the force of gravity applied to the object. If you haven't taken a physics class, please do so.. Also, please start reading the usage documentation. There's seriously a function named almos...
by kloplop321
Wed Feb 22, 2012 7:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: Automated flying object
Replies: 4
Views: 1661

Re: Automated flying object

First you have to negate the forces which gravity apply, and then apply forces in whichever direction you wish.

Why did you post this in two places..?
by kloplop321
Wed Feb 22, 2012 7:20 pm
Forum: General Bullet Physics Support and Feedback
Topic: Internal edges for btBoxShape
Replies: 3
Views: 1432

Re: Internal edges for btBoxShape

I've tried to use a fully dynamic character model and I usually end up getting stuck or lodged into things too because I'm using forces but limiting the angular movement.

Boxes should be more stable than trimeshes (currently, since over trimeshes, you can get a weird issue when going across edges.)
by kloplop321
Wed Feb 22, 2012 4:47 am
Forum: General Bullet Physics Support and Feedback
Topic: Help me achieve more realism with my dice?
Replies: 9
Views: 3387

Re: Help me achieve more realism with my dice?

I think its because you are only determining a direction on only one dimension, and using random values to do the rest, completely ignoring the actual context of the phone's movement. It would be a lot easier if you use Quicktime to record a portion of your screen of an iPhone Simulator than to reco...
by kloplop321
Tue Feb 21, 2012 7:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: Help me achieve more realism with my dice?
Replies: 9
Views: 3387

Re: Help me achieve more realism with my dice?

Instead of applying a randomly centered impulse to the dice, have you tried to make the cage a kinematic body and move the cage identically(but maybe scaled in force/distance) to how the device shakes? You would need to move the camera and rotate and so on, but I think it would provide a much more r...
by kloplop321
Sun Feb 19, 2012 10:15 pm
Forum: General Bullet Physics Support and Feedback
Topic: Very short Raycasts sometimes fail
Replies: 2
Views: 1312

Re: Very short Raycasts sometimes fail

This might have to do with the margins on shapes, but I'm not sure.

Is the % consistent? Like if you run it with the exact same scene multiple times, do you get the same results?

Your last question would definitely be handy to know.
by kloplop321
Sat Feb 18, 2012 12:29 am
Forum: General Bullet Physics Support and Feedback
Topic: link error
Replies: 4
Views: 2769

Re: link error

You need to have OpenGLSupport_Debug.lib in the location ..\..\lib\Debug\OpenGLSupport_Debug.lib

You did not configure the visual studio project correctly with cmake.
by kloplop321
Thu Feb 16, 2012 9:06 pm
Forum: General Bullet Physics Support and Feedback
Topic: what is the purpose of those methods ?
Replies: 3
Views: 1466

Re: what is the purpose of those methods ?

You don't even need to use all of what is in the demo for requirements like that. But to answer your question btCollisionWorld::ContactResultCallback::addSingleResult(...) This adds a result to a Contact result structure which you can get information from later. The manifold point is where the conta...
by kloplop321
Thu Feb 16, 2012 7:27 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Collision Detection Frontiers/5 Year Projection
Replies: 2
Views: 2513

Re: Collision Detection Frontiers/5 Year Projection

I would say that there's increasing emphasis on using Finite Element Method. It has always been used for structural analysis with varying precision in the old days to be fast enough to calculate. It can be approximately done in real time now, but the problem of optimization still has more room to go...
by kloplop321
Thu Feb 16, 2012 7:23 pm
Forum: General Bullet Physics Support and Feedback
Topic: SImulating Springs with the btgeneric6dofspringconstraint
Replies: 4
Views: 1914

Re: SImulating Springs with the btgeneric6dofspringconstrain

You should probably take a look at the restitution factor, it might be defaulting to something which does not match MATLAB. As in the stiffness constant that I set is being reset somewhere in bullet? Where would this be happening? Why? I was confused, I was thinking about the SliderConstraint. Do y...
by kloplop321
Thu Feb 16, 2012 2:36 am
Forum: General Bullet Physics Support and Feedback
Topic: SImulating Springs with the btgeneric6dofspringconstraint
Replies: 4
Views: 1914

Re: SImulating Springs with the btgeneric6dofspringconstrain

You should probably take a look at the restitution factor, it might be defaulting to something which does not match MATLAB. Additionally, Bullet is not made for scientific research and it is discouraged to use it for such, as it is only for approximating a simulation within a desirably short simulat...