예제 #1
0
        public void Timestep(Simulation simulation, float dt, IThreadDispatcher threadDispatcher = null)
        {
            simulation.Sleep(threadDispatcher);
            Slept?.Invoke(dt, threadDispatcher);

            simulation.IntegrateVelocitiesBoundsAndInertias(dt, threadDispatcher);
            BeforeCollisionDetection?.Invoke(dt, threadDispatcher);

            simulation.CollisionDetection(dt, threadDispatcher);
            CollisionsDetected?.Invoke(dt, threadDispatcher);


            int     count = simulation.Bodies.ActiveSet.Count;
            ref var baseConveyorSettings = ref simulation.Bodies.ActiveSet.ConveyorSettings[0];
        public void Timestep(Simulation simulation, float dt, IThreadDispatcher threadDispatcher = null)
        {
            simulation.Sleep(threadDispatcher);
            Slept?.Invoke(dt, threadDispatcher);

            simulation.IntegrateVelocitiesBoundsAndInertias(dt, threadDispatcher);
            BeforeCollisionDetection?.Invoke(dt, threadDispatcher);

            simulation.CollisionDetection(dt, threadDispatcher);
            CollisionsDetected?.Invoke(dt, threadDispatcher);

            simulation.Solve(dt, threadDispatcher);
            ConstraintsSolved?.Invoke(dt, threadDispatcher);

            simulation.IntegratePoses(dt, threadDispatcher);
            PosesIntegrated?.Invoke(dt, threadDispatcher);

            simulation.IncrementallyOptimizeDataStructures(threadDispatcher);
        }
        public void Timestep(Simulation simulation, float dt, IThreadDispatcher threadDispatcher = null)
        {
            //Note that there is a reason to put the sleep *after* velocity integration. That sounds a little weird, but there's a good reason:
            //When the narrow phase activates a bunch of objects in a pile, their accumulated impulses will represent all forces acting on them at the time of sleep.
            //That includes gravity. If we sleep objects *before* gravity is applied in a given frame, then when those bodies3D are awakened, the accumulated impulses
            //will be less accurate because they assume that gravity has already been applied. This can cause a small bump.
            //So, velocity integration (and deactivation candidacy management) could come before sleep.

            //Sleep at the start, on the other hand, stops some forms of unintuitive behavior when using direct awakenings. Just a matter of preference.
            simulation.Sleep(threadDispatcher);
            Slept?.Invoke(dt, threadDispatcher);

            //Note that pose integrator comes before collision detection and solving. This is a shift from v1, where collision detection went first.
            //This is a tradeoff:
            //1) Any externally set velocities will be integrated without input from the solver. The v1-style external velocity control won't work as well-
            //the user would instead have to change velocities after the pose integrator runs. This isn't perfect either, since the pose integrator is also responsible
            //for updating the bounding boxes used for collision detection.
            //2) By bundling bounding box calculation with pose integration, you avoid redundant pose and velocity memory accesses.
            //3) Generated contact positions are in sync with the integrated poses.
            //That's often helpful for gameplay purposes- you don't have to reinterpret contact data when creating graphical effects or positioning sound sources.

            //#1 is a difficult problem, though. There is no fully 'correct' place to change velocities. We might just have to bite the bullet and create a
            //inertia tensor/bounding box update separate from pose integration. If the cache gets evicted in between (virtually guaranteed unless no stages run),
            //this basically means an extra 100-200 microseconds per frame on a processor with ~20GBps bandwidth simulating 32768 bodies3D.

            //Note that the reason why the pose integrator comes first instead of, say, the solver, is that the solver relies on world space inertias calculated by the pose integration.
            //If the pose integrator doesn't run first, we either need
            //1) complicated on demand updates of world inertia when objects are added or local inertias are changed or
            //2) local->world inertia calculation before the solver.
            simulation.IntegrateBodiesAndUpdateBoundingBoxes(dt, threadDispatcher);
            BeforeCollisionDetection?.Invoke(dt, threadDispatcher);

            simulation.CollisionDetection(dt, threadDispatcher);
            CollisionsDetected?.Invoke(dt, threadDispatcher);

            simulation.Solve(dt, threadDispatcher);
            ConstraintsSolved?.Invoke(dt, threadDispatcher);

            simulation.IncrementallyOptimizeDataStructures(threadDispatcher);
        }
        public void Timestep(Simulation simulation, float dt, IThreadDispatcher threadDispatcher = null)
        {
            simulation.Sleep(threadDispatcher);
            Slept?.Invoke(dt, threadDispatcher);

            simulation.PredictBoundingBoxes(dt, threadDispatcher);
            BeforeCollisionDetection?.Invoke(dt, threadDispatcher);

            simulation.CollisionDetection(dt, threadDispatcher);
            CollisionsDetected?.Invoke(dt, threadDispatcher);

            Debug.Assert(SubstepCount >= 0, "Substep count should be positive.");
            var substepDt = dt / SubstepCount;

            for (int substepIndex = 0; substepIndex < SubstepCount; ++substepIndex)
            {
                SubstepStarted?.Invoke(substepIndex, dt, threadDispatcher);
                if (substepIndex > 0)
                {
                    //This takes the place of collision detection for the substeps. It uses the current velocity to update penetration depths.
                    //It's definitely an approximation, but it's important for avoiding some obviously weird behavior.
                    //Note that we do not run this on the first iteration- the actual collision detection above takes care of it.
                    simulation.IncrementallyUpdateContactConstraints(substepDt, threadDispatcher);
                    ContactConstraintsUpdatedForSubstep?.Invoke(substepIndex, dt, threadDispatcher);
                }
                simulation.IntegrateVelocitiesAndUpdateInertias(substepDt, threadDispatcher);
                VelocitiesIntegrated?.Invoke(substepIndex, dt, threadDispatcher);

                simulation.Solve(substepDt, threadDispatcher);
                ConstraintsSolved?.Invoke(substepIndex, dt, threadDispatcher);

                simulation.IntegratePoses(substepDt, threadDispatcher);
                PosesIntegrated?.Invoke(substepIndex, dt, threadDispatcher);
                SubstepEnded?.Invoke(substepIndex, dt, threadDispatcher);
            }
            SubstepsComplete?.Invoke(dt, threadDispatcher);

            simulation.IncrementallyOptimizeDataStructures(threadDispatcher);
        }