Search found 22 matches

by Louis Langholtz
Wed Jan 03, 2018 11:10 am
Forum: General Discussion
Topic: [Help] How to unable (use) fixed point mode in box2d
Replies: 1
Views: 185

Re: [Help] How to unable (use) fixed point mode in box2d

Hi null_pointer_2303. Yes. An implementation of a fixed point numeric type could be completely 100% reproducible on all supported platforms. Actually any numeric type could be implemented to provide 100% reproducible results - at least on supported platforms. How to use it is harder to explain. You ...
by Louis Langholtz
Wed Oct 25, 2017 7:38 pm
Forum: General Discussion
Topic: Turning speed limits
Replies: 3
Views: 396

Re: Turning speed limits

There is a rotational speed limit of b2_maxRotation (which is set to 0.5 * b2_pi). That's a limit per step however which at 60 steps / second of simulated time, is over 90 radians per second. That will be the max rotational speed that a body can be accelerated to or set to short of upping the max ro...
by Louis Langholtz
Fri May 05, 2017 11:02 am
Forum: General Discussion
Topic: why no early out for solving velocity constraints?
Replies: 0
Views: 515

why no early out for solving velocity constraints?

In the iterative solving in the physics engine library code there are two calls to the b2ContactSolver::SolveVelocityConstraints() method: one from b2Island::Solve() and one from b2Island::SolveTOI(). In both places, b2ContactSolver::SolveVelocityConstraints() gets called repeatedly. This is similar...
by Louis Langholtz
Fri May 05, 2017 7:43 am
Forum: Bugs, Requests, and Feedback
Topic: Advice questions to Erin on Concave Shape Dynamics.
Replies: 1
Views: 1871

Re: Advice questions to Erin on Concave Shape Dynamics.

Hi mcourteaux, Great questions! I have been wondering about concave dynamics too. In a sense, Box2D already supports concave dynamic shapes. Just not as a subclass of b2Shape. But as multiple convex fixtures on a single body they are. If we accept then that concave dynamics are already supported via...
by Louis Langholtz
Fri May 05, 2017 7:22 am
Forum: Bugs, Requests, and Feedback
Topic: Box2D Threading Raycasts
Replies: 1
Views: 837

Re: Box2D Threading Raycasts

HI engineer202, Sounds like some interesting stuff you're doing! I am very curious about the following: 1. What's the MT version of Box2D that you switched to using? 2. Are you certain that the MT version that you switched to is really thread safe? 3. If so, how was that ascertained/proved? 3. Did y...
by Louis Langholtz
Fri May 05, 2017 7:00 am
Forum: Bugs, Requests, and Feedback
Topic: Objects fall through the ground. Gravity
Replies: 1
Views: 530

Re: Objects fall through the ground. Gravity

It may be too late by now but if this is still a problem you may also want to post this issue on one of the StackExchange websites like https://gamedev.stackexchange.com .
by Louis Langholtz
Fri May 05, 2017 6:54 am
Forum: Bugs, Requests, and Feedback
Topic: "skin" radius influence on manifold contact point locations
Replies: 1
Views: 355

Re: "skin" radius influence on manifold contact point locations

UPDATE: I've been continuing to investigate this. Some experimenting I've done since originally posting this and the results I've found I've posted online in case anyone's interested. Among other things, I've been able to modify the handling such that there's no need for "ghost vertices" ...
by Louis Langholtz
Fri May 05, 2017 6:45 am
Forum: General Discussion
Topic: Contact constraint derivation question
Replies: 1
Views: 448

Re: Contact constraint derivation question

Hi Himura78, I like your topic and questions. Any chance you can reference particular functions or methods in Box2D that relate to these? Sounds like you have theoretically thought about these things but perhaps haven't tried them out on Box2D code. Is that a fair assessment? I ask because I'd love ...
by Louis Langholtz
Wed Apr 12, 2017 10:10 pm
Forum: Bugs, Requests, and Feedback
Topic: b2WheelJoint uninitialized variable
Replies: 2
Views: 947

Re: b2WheelJoint uninitialized variable

Nice find! What about m_ax? Looks like that could be used uninitialized too in the 0 frequency case. Also, what if the user creates the joint with a frequency and then later changes that frequency to zero? I don't think setting m_sAx and m_sBx to 0.0f in the constructor will work in that case. They ...
by Louis Langholtz
Tue Mar 28, 2017 9:04 am
Forum: General Discussion
Topic: applyforce inconsistent behavior
Replies: 3
Views: 784

Re: applyforce inconsistent behavior

Hello and welcome to the Box2D forums. I don't know that I can answer your question but wanted to address it anyway in the hopes of possibly helping. In your initial post you made some statements that I'd like to address: When I run my program on the iPad air I see inconsistent behavior. From your s...

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