Real-Time Physics Simulation Forum

Looks pretty damn good. Is this code Bullet or other engine specific?

--EK

Intuitively, that kinda makes sense. When you think of moving your leg, you think of the speed you WANT it to move. Which is why you will stumble/trip/whatever when something impedes the "expected velocity" of your foot.

Sounds interesting

--EK

Yes, I have implemented the "column-based" approach (where there is a triangular column for every surface triangle). It has a couple of problems which need to be resolved. Firstly there is still an issue that when an object is completely "submerged" under the terrain, the contact...

Whether this is a MSVC 7.1 issue or something else I am not sure of; but the "libquickstep" will not compile in MSVC 2003 (i.e. MSVC 7.1) as <intrin.h> does not exist. You also need to add #include <memory.h> in order for memset to be defined in the "#ifdef _MSC_VER" (the __GNUC_...

If you make those columns tall, you might get objects wedged between them with only horizontal contact normals. The object will then ping-pong back-and-forth falling into the abyss. I have thought of this and is something I have discussed with Erwin (briefly) in the beginning. For any face but the ...

I am working on implementing a volumetric approach to the height-field collision shape so that fast moving objects are detected as colliding with the terrain even if they pass through thin shell of triangles making up it's surface. I am making a new shape class for this as the existing height-field ...

Yeah, I am looking at it already. Hence the discussion about trying to integrate the idea of buoyancy & volumetric terrains.

Will try to get a prisms version working in the next couple of days (sorry, but my baby boy is sick so time is limited to the 2.5hrs train trip I do to/from work)

--EK

I've been looking at changing the height-field collision detection & resolution (as detailed in another thread) and this seems to have similar requirements and/or implementation details. Perhaps there is a way to have both bouyancy and "volumetric" height-fields catered for in the same...

There is still some "special case" stuff that would only apply to height-field processing (namely the collision normal needing to point UP for all contacts but those on the single surface triangle). As long as the callback allows for sucvh an override - I think this will be a nice clean so...

The solution I was thinking of (which you mentioned) was to collide with triangular prisms rather than just the surface triangles. The issue I am trying to resolve with this is that the contact normal for all faces (except the surface triangle) would need to be "up" in order to push penetr...

I noticed a "bug" in the height-field collision shape mentioned by someone else in the forums and have been able to reproduce this myself. The problem is (as expected) that the height-field collision shape only checks for collision against the "surface triangles", yet it is actua...

Sorry, but I have to disagree there. Why does GPL mean only hobbyists can contribute? This is nonsense. GPL simply means that the code has to be available to the interested people and prevents stealing code ( taking code of others and selling it as your own idea ). It's a protection and not a hindr...

Well, for the sake of completeness/clarity... btHingeConstraint does not rotate the wheels of a car for you and (as you rightfully mentioned) the 6DOF Constraint is not "officially" part of the Bullet SDK. Nor was the 6Dof constraint out at the time of posting :) I have not yet had time to...

The only thing missing that I am looking for (currently in ODE) are rotational motors for wheels on a vehicle. As I understand it, we can set rotational velocity but not "rotational torque". Other than that, I have to agree with Erwin. Bullet is now pulling ahead of ODE in terms of perform...

Two mini-subjects now to respond to.... General Character vs World Simulation: So, assuming I have this correct, there are X steps in your simulation: You simulate the world without the character included You obtain the impulses needed to drive the character in the world from your kinematic model (i...