CURRENT PRIORITIES ================================================= Redo BulletSimAPI to allow native C# implementation of Bullet option. Avatar movement flying into a wall doesn't stop avatar who keeps appearing to move through the obstacle walking up stairs is not calibrated correctly (stairs out of Kepler cabin) avatar capsule rotation completed llMoveToTarget Enable vehicle border crossings (at least as poorly as ODE) Terrain skirts Avatar created in previous region and not new region when crossing border Vehicle recreated in new sim at small Z value (offset from root value?) (DONE) Vehicle movement on terrain smoothness Vehicle script tuning/debugging Avanti speed script Weapon shooter script limitMotorUp calibration (more down?) Boats float low in the water Add material densities to the material types. CRASHES ================================================= 20121129.1411: editting/moving phys object across region boundries causes crash getPos-> btRigidBody::upcast -> getBodyType -> BOOM 20121128.1600: mesh object not rezzing (no physics mesh). Causes many errors. Doesn't stop after first error with box shape. Eventually crashes when deleting the object. 20121206.1434: rez Sam-pan into OSGrid BulletSim11 region Immediate simulator crash. Mono does not output any stacktrace and log just stops after reporting taint-time linking of the linkset. VEHICLES TODO LIST: ================================================= Angular motor direction is global coordinates rather than local coordinates Border crossing with linked vehicle causes crash Vehicles (Move smoothly) Add vehicle collisions so IsColliding is properly reported. Needed for banking, limitMotorUp, movementLimiting, ... VehicleAddForce is not scaled by the simulation step but it is only applied for one step. Should it be scaled? Some vehicles should not be able to turn if no speed or off ground. Cannot edit/move a vehicle being ridden: it jumps back to the origional position. Neb car jiggling left and right Happens on terrain and any other mesh object. Flat cubes are much smoother. This has been reduced but not eliminated. Implement referenceFrame for all the motion routines. Angular motion around Z moves the vehicle in world Z and not vehicle Z in ODE. Verify that angular motion specified around Z moves in the vehicle coordinates. Verify llGetVel() is returning a smooth and good value for vehicle movement. llGetVel() should return the root's velocity if requested in a child prim. Implement function efficiency for lineaar and angular motion. After getting off a vehicle, the root prim is phantom (can be walked through) Need to force a position update for the root prim after compound shape destruction Linkset explosion after three "rides" on Nebadon lite vehicle (LinksetConstraint) For limitMotorUp, use raycast down to find if vehicle is in the air. Remove vehicle angular velocity zeroing in BSPrim.UpdateProperties(). A kludge that isn't fixing the real problem of Bullet adding extra motion. Incorporate inter-relationship of angular corrections. For instance, angularDeflection and angularMotorUp will compute same X or Y correction. When added together creates over-correction and over-shoot and wabbling. BULLETSIM TODO LIST: ================================================= Implement an avatar mesh shape. The Bullet capsule is way too limited. Consider just hand creating a vertex/index array in a new BSShapeAvatar. Revisit CollisionMargin. Builders notice the 0.04 spacing between prims. Duplicating a physical prim causes old prim to jump away Dup a phys prim and the original become unselected and thus interacts w/ selected prim. Scenes with hundred of thousands of static objects take a lot of physics CPU time. BSPrim.Force should set a continious force on the prim. The force should be applied each tick. Some limits? Gun sending shooter flying. Collision margin (gap between physical objects lying on each other) Boundry checking (crashes related to crossing boundry) Add check for border edge position for avatars and objects. Verify the events are created for border crossings. Avatar rotation (check out changes to ScenePresence for physical rotation) Avatar running (what does phys engine need to do?) Small physical objects do not interact correctly Create chain of .5x.5x.1 torui and make all but top physical so to hang. The chain will fall apart and pairs will dance around on ground Chains of 1x1x.2 will stay connected but will dance. Chains above 2x2x.4 are more stable and get stablier as torui get larger. Add PID motor for avatar movement (slow to stop, ...) setForce should set a constant force. Different than AddImpulse. Implement raycast. Implement ShapeCollection.Dispose() Implement water as a plain so raycasting and collisions can happen with same. Add osGetPhysicsEngineName() so scripters can tell whether BulletSim or ODE Also osGetPhysicsEngineVerion() maybe. Linkset.Position and Linkset.Orientation requre rewrite to properly return child position. LinksetConstraint acts like it's at taint time!! Implement LockAngularMotion -- implements llSetStatus(ROTATE_AXIS_*, T/F) Should the different PID factors have non-equal contributions for different values of Efficiency? Selecting and deselecting physical objects causes CPU processing time to jump http://www.youtube.com/watch?v=Hjg57fWg8yI&hd=1 put thousand physical objects, select and deselect same. CPU time will be large. Re-implement buoyancy as a separate force on the object rather than diddling gravity. Register a pre-step event to add the force. More efficient memory usage when passing hull information from BSPrim to BulletSim Avatar movement motor check for zero or small movement. Somehow suppress small movements when avatar has stopped and is just standing. Simple test for near zero has the problem of preventing starting up (increase from zero) especially when falling. Physical and phantom will drop through the terrain LINKSETS ====================================================== Offset the center of the linkset to be the geometric center of all the prims Not quite the same as the center-of-gravity Linksets should allow collisions to individual children Add LocalID to children shapes in LinksetCompound and create events for individuals LinksetCompound: when one of the children changes orientation (like tires turning on a vehicle, the whole compound object is rebuilt. Optimize this so orientation/position of individual children can change without a rebuild. Verify/think through scripts in children of linksets. What do they reference and return when getting position, velocity, ... Confirm constraint linksets still work after making all the changes for compound linksets. Add 'changed' flag or similar to reduce the number of times a linkset is rebuilt. For compound linksets, add ability to remove or reposition individual child shapes. Disable activity of passive linkset children. Since the linkset is a compound object, the old prims are left lying around and need to be phantomized so they don't collide, ... Speed up creation of large physical linksets For instance, sitting in Neb's car (130 prims) takes several seconds to become physical. REALLY bad for very large physical linksets (freezes the sim for many seconds). Eliminate collisions between objects in a linkset. (LinksetConstraint) Have UserPointer point to struct with localID and linksetID? Objects in original linkset still collide with each other? MORE ====================================================== Test avatar walking up stairs. How does compare with SL. Radius of the capsule affects ability to climb edges. Debounce avatar contact so legs don't keep folding up when standing. Implement LSL physics controls. Like STATUS_ROTATE_X. Add border extensions to terrain to help region crossings and objects leaving region. Use a different capsule shape for avatar when sitting LL uses a pyrimidal shape scaled by the avatar's bounding box http://wiki.secondlife.com/wiki/File:Avmeshforms.png Performance test with lots of avatars. Can BulletSim support a thousand? Optimize collisions in C++: only send up to the object subscribed to collisions. Use collision subscription and remove the collsion(A,B) and collision(B,A) Check whether SimMotionState needs large if statement (see TODO). Implement 'top colliders' info. Avatar jump Performance measurement and changes to make quicker. Implement detailed physics stats (GetStats()). Measure performance improvement from hulls Test not using ghost objects for volume detect implementation. Performance of closures and delegates for taint processing Are there faster ways? Is any slowdown introduced by the existing implementation significant? Is there are more efficient method of implementing pre and post step actions? See http://www.codeproject.com/Articles/29922/Weak-Events-in-C Physics Arena central pyramid: why is one side permiable? In SL, perfect spheres don't seem to have rolling friction. Add special case. Enforce physical parameter min/max: Gravity: [-1, 28] Friction: [0, 255] Density: [1, 22587] Restitution [0, 1] http://wiki.secondlife.com/wiki/Physics_Material_Settings_test Avatar attachments have no mass? http://forums-archive.secondlife.com/54/f0/31796/1.html INTERNAL IMPROVEMENT/CLEANUP ================================================= Create the physical wrapper classes (BulletBody, BulletShape) by methods on BSAPITemplate and make their actual implementation Bullet engine specific. For the short term, just call the existing functions in ShapeCollection. Consider moving prim/character body and shape destruction in destroy() to postTimeTime rather than protecting all the potential sets that might have been queued up. Remove unused fields from ShapeData (not used in API2) Remove unused fields from pinned memory shared parameter block Create parameter variables in BSScene to replace same. Breakout code for mesh/hull/compound/native into separate BSShape* classes Standardize access to building and reference code. The skeleton classes are in the sources but are not complete or linked in. Make BSBody and BSShape real classes to centralize creation/changin/destruction Convert state and parameter calls from BulletSimAPI direct calls to calls on BSBody and BSShape Generalize Dynamics and PID with standardized motors. Generalize Linkset and vehicles into PropertyManagers Methods for Refresh, RemoveBodyDependencies, RestoreBodyDependencies Potentially add events for shape destruction, etc. Complete implemention of preStepActions Replace vehicle step call with prestep event. Is there a need for postStepActions? postStepTaints? Implement linkset by setting position of children when root updated. (LinksetManual) Linkset implementation using manual prim movement. LinkablePrim class? Would that simplify/centralize the linkset logic? BSScene.UpdateParameterSet() is broken. How to set params on objects? Remove HeightmapInfo from terrain specification Since C++ code does not need terrain height, this structure et al are not needed. Add floating motor for BS_FLOATS_ON_WATER so prim and avatar will bob at the water level. BSPrim.PositionSanityCheck(). Should taints check for existance or activeness of target? When destroying linksets/etc, taints can be generated for objects that are actually gone when the taint happens. Crashes don't happen because the taint closure keeps the object from being freed, but that is just an accident. Possibly have and 'active' flag that is checked by the taint processor? Parameters for physics logging should be moved from BSScene to BSParam (at least boolean ones) Can some of the physical wrapper classes (BulletBody, BulletWorld, BulletShape) be 'sealed'? There are TOO MANY interfaces from BulletSim core to Bullet itself Think of something to eliminate one or more of the layers THREADING ================================================= Do taint action immediately if not actually executing Bullet. Add lock around Bullet execution and just do taint actions if simulation is not happening. DONE DONE DONE DONE ================================================= Cleanup code in BSDynamics by using motors. (Resolution: started) Consider implementing terrain with a mesh rather than heightmap. (Resolution: done) Would have better and adjustable resolution. Build terrain mesh so heighmap is height of the center of the square meter. Resolution: NOT DONE: SL and ODE define meter square as being at one corner with one diagional. Terrain as mesh. (Resolution: done) How are static linksets seen by the physics engine? Resolution: they are not linked in physics. When moved, all the children are repositioned. Convert BSCharacter to use all API2 (Resolution: done) Avatar pushing difficult (too heavy?) Use asset service passed to BulletSim to get sculptie bodies, etc. (Resolution: done) Remove old code in DLL (all non-API2 stuff). (Resolution: done) Measurements of mega-physical prim performance (with graph) (Resolution: done, email) Debug Bullet internal stats output (why is timing all wrong?) Resolution: Bullet stats logging only works with a single instance of Bullet (one region). Implement meshes or just verify that they work. (Resolution: they do!) Do prim hash codes work for sculpties and meshes? (Resolution: yes) Linkset implementation using compound shapes. (Resolution: implemented LinksetCompound) Compound shapes will need the LocalID in the shapes and collision processing to get it from there. Light cycle not banking (Resolution: It doesn't. Banking is roll adding yaw.) Package Bullet source mods for Bullet internal stats output (Resolution: move code into WorldData.h rather than relying on patches) Single prim vehicles don't seem to properly vehiclize. (Resolution: mass was not getting set properly for single prim linksets) Add material type linkage and input all the material property definitions. Skeleton classes and table are in the sources but are not filled or used. (Resolution: Neb vehicle taking > 25ms of physics time!! (Resolution: compound linksets were being rebuild WAY too often) Avatar height off after unsitting (floats off ground) Editting appearance then moving restores. Must not be initializing height when recreating capsule after unsit. (Resolution: confusion of scale vs size for native objects removed) Light cycle falling over when driving (Resolution: implemented angularMotorUp) Should vehicle angular/linear movement friction happen after all the components or does it only apply to the basic movement? (Resolution: friction added before returning newly computed motor value. What is expected by some vehicles (turning up friction to moderate speed)) Tune terrain/object friction to be closer to SL. (Resolution: added material type with friction and resolution) Smooth avatar movement with motor (DONE) Should motor update be all at taint-time? (Yes, DONE) Fix avatar slowly sliding when standing (zero motion when stopped) (DONE) (Resolution: added BSVMotor for avatar starting and stopping) llApplyImpulse() Compare mass/movement in OS and SL. Calibrate actions. (DONE) (Resolution: tested on SL and OS. AddForce scales the force for timestep) llSetBuoyancy() (DONE) (Resolution: Bullet resets object gravity when added to world. Moved set gravity) Avatar density is WAY off. Compare and calibrate with what's in SL. (DONE) (Resolution: set default density to 3.5 (from 60) which is closer to SL)