Version Roadmap

Post and discuss features you'd like to see in the BEPUphysics library.
Spankenstein
Posts: 249
Joined: Wed Nov 17, 2010 1:49 pm

Re: Version Roadmap

Post by Spankenstein »

I've attached a small project highlighting the weapon problem with character control.

Press 'c' to activate/deactivate the character controller.
WASD keys to move.
Mouse to look around.

- 'IsFixedTimeStep = false' causes the CharacterAABB (green) to jitter when moving
- 'weaponBox' (blue) never jitters but doesn't use the physics engine
- 'weaponBox2' (blue) always jitters no matter what

How can I fix the jittering?
Attachments
ProblemDemo.rar
Demo of the problem
(703.17 KiB) Downloaded 1859 times
Spankenstein
Posts: 249
Joined: Wed Nov 17, 2010 1:49 pm

Re: Version Roadmap

Post by Spankenstein »

Solves the problem for non entities (objects that aren't associated with the physics space):

'CharacterControllerInput' should update BEFORE the associated camera updates.

Not sure what to do about entities though but the first person weapon doesn't need to be an entity. :)
Norbo
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Re: Version Roadmap

Post by Norbo »

I don't see any unexpected behavior:

-When IsFixedTimeStep = true and Space.Update() is not given an elapsed time, the game runs at a proper speed and nothing jitters. AABB's appear to be a frame behind, because they are. AABB's are computed at the beginning of a frame for broad phase use. Entity positions are computed at the end of a frame.

-When IsFixedTimeStep = false and Space.Update() is not given an elapsed time, it runs extremely fast, but without any apparent issues (though it's hard to tell :))

-When IsFixedTImeStep = false and Space.Update() is given an elapsed time, jitter occurs as expected. This is because of the internal time stepping I mentioned earlier. It accumulates time, and when sufficient time elapses, it performs a time step. Since it cannot do fractional time steps, sometimes there will be a little time left over. The slightly irregular updates cause what appears to be 'jitter.' This is addressed by using interpolation buffers. Interpolation buffers blend together entities' positions and orientations with the time remainder to produce smooth movement. Information about it can be found in the asynchronous update documentation, though interpolation has a purpose outside of just updating on a second thread (as you've encountered :)): http://bepuphysics.codeplex.com/wikipag ... umentation
Spankenstein
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Re: Version Roadmap

Post by Spankenstein »

Cool. Thanks for that. I understand what's going on now :)
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated the roadmap to reflect v0.16.2's release.
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated the road map to reflect v1.0.0's imminent release.
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated the roadmap to reflect v1.0.0's release.
Fe_Yoshi
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Joined: Tue Jul 04, 2006 5:05 pm
Location: New Tower!

Re: Version Roadmap

Post by Fe_Yoshi »

Will the road map be updated to reflect v1.0.0's past release?
It's simple, just take the hydraulic phase ship emulator and attach it to the photon particle emitter, BAM, new tower!
Norbo
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Re: Version Roadmap

Post by Norbo »

It was already updated tomorrow due to superluminal tachyonic disturbances.
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated the road map to reflect v1.2.0's release.
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated the roadmap... because I felt like it.
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated main post to reflect the murdering of the development fork and the pushing of all commits to the main branch directly. Hopefully, less people will think BEPUphysics is dead now!
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated main post to reflect recent changes.
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated reflect main to recent post changes.
Norbo
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Re: Version Roadmap

Post by Norbo »

Updated main post to reflect v1.3.0's upcoming release.
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