Support for physics is done by skiping the modifiers that
don't support mapping to original mesh. This mapping is
required to report the hit polygon to the application
by the rayCast() function.
Support for graphics is done by using the same render
function that blender uses for the 3D view. This guantees
equal result.
Limitation: there is still a known bug if all these conditions are met:
- Display list enabled
- Old tex face with a several textures mapped to the same material
- no armature or shape keys
- active modifiers
In this case, only a part of the mesh will be rendered
with the wrong texture. To avoid this bug, use the GLSL
materials or make sure to have 1 material=1 texture in
your old tex face objects.
A btBvhTriangleMeshShape object is created when converting
a mesh to physics, also in case of Soft body although the
soft body will not use it (it only uses the mesh interface).
This patch keeps this system for compatibility with the
KX converter but avoids the creation of the BVH structure,
which consumes a lots of CPU. This should speed up
significantly the conversion of large mesh to softbody.
A secondary optimization is that the sharing of shapeInfo
is extended to rigid body using gImpact. Before it was
only active between static body and soft body.
Most likely will not compile for others, I'd appreciate any build errors
and missing files reports (I can never seem to get everything committed
and all the build systems working without help).
Porting over the sculpt/multires tools was a breeze,
thanks goes to brecht for a design that didn't exclude
ngons and was easy to port.
Note that I've not tested externally-backed multires
file support yet. Also, I still need to write version
patch code for some cases.
Some notes:
* Like trunk, topological changes don't update multires right,
so e.g. subdivide will duplicate multires data on the new faces,
instead of subdividing it.
* If you set the debug value (ctrl-alt-d) to 1 it'll turn on
my experiments in speeding up sculpting on higher-res multires
meshes (but note it makes partial redraw not completely accurate).
* There's a bug where you have to go through editmode to get out
of sculpt mode, not sure if I inherited or created this myself.
Even a static mesh can be used as replacement: the mesh
will be instantiated with the soft body settings of the
object. The position and orientation of the soft body
is preserved after the replacement.
Known limitation: the velocity of the soft body is reset
aftet the replacement. This is because soft body don't
have a well defined velocity.
Add support back for reinstancePhysics mesh, a frequently requested feature in the BGE forums.
from what I can tell Sumo supported this but bullet never did.
Currently only accessible via python at the moment.
- rigid body, dynamic, static types work.
- instanced physics meshes are modified too.
- compound shapes are not supported.
Physics mesh can be re-instanced from...
* shape keys & armature deformations
* subsurf (any other modifiers too)
* RAS_TexVert's (can be modified from python)
Moved the reinstancePhysicsMesh functions from RAS_MeshObject into KX_GameObject since the physics data is stored here.
video and blend file demo.
http://www.graphicall.org/ftp/ideasman42/reinstance.ogvhttp://www.graphicall.org/ftp/ideasman42/reinstance_demo.blend
Example is a cube that lands on a plane, sleeps after some time, a script changes the scale.
It would still use the scale when the object first went to sleep.
reported on blenderartist.
http://blenderartists.org/forum/showthread.php?t=158617
- Typo in occlusion variable init "m_buffer == NULL;" -> "m_buffer = NULL;"
CcdPhysicsEnvironment.cpp and CcdPhysicsController.cpp had too many warnings, fixed most of them.
http://blenderartists.org/forum/showpost.php?p=1382653&postcount=102
(todo: expose this setting in World setting GUI)
Expose contact processing threshold in Advanced GUI, next to rigid body margin, called CPT.
Default to 1, makes rigid body stacking a bit more stable, smaller values makes sliding easier (at the cost of easier jittering).
Disabled for 'dynamic' objects that don't rotate, because characters etc. always need smooth sliding.
A new type of "Sensor" physics object is available in the GE for advanced
collision management. It's called Sensor for its similarities with the
physics objects that underlie the Near and Radar sensors.
Like the Near and Radar object it is:
- static and ghost
- invisible by default
- always active to ensure correct collision detection
- capable of detecting both static and dynamic objects
- ignoring collision with their parent
- capable of broadphase filtering based on:
* Actor option: the collisioning object must have the Actor flag set to be detected
* property/material: as specified in the collision sensors attached to it
Broadphase filtering is important for performance reason: the collision points
will be computed only for the objects that pass the broahphase filter.
- automatically removed from the simulation when no collision sensor is active on it
Unlike the Near and Radar object it can:
- take any shape, including triangle mesh
- be made visible for debugging (just use the Visible actuator)
- have multiple collision sensors using it
Other than that, the sensor objects are ordinary objects. You can move them
freely or parent them. When parented to a dynamic object, they can provide
advanced collision control to this object.
The type of collision capability depends on the shape:
- box, sphere, cylinder, cone, convex hull provide volume detection.
- triangle mesh provides surface detection but you can give some volume
to the suface by increasing the margin in the Advanced Settings panel.
The margin applies on both sides of the surface.
Performance tip:
- Sensor objects perform better than Near and Radar: they do less synchronizations
because of the Scenegraph optimizations and they can have multiple collision sensors
on them (with different property filtering for example).
- Always prefer simple shape (box, sphere) to complex shape whenever possible.
- Always use broadphase filtering (avoid collision sensor with empty propery/material)
- Use collision sensor only when you need them. When no collision sensor is active
on the sensor object, it is removed from the simulation and consume no CPU.
Known limitations:
- When running Blender in debug mode, you will see one warning line of the console:
"warning btCollisionDispatcher::needsCollision: static-static collision!"
In release mode this message is not printed.
- Collision margin has no effect on sphere, cone and cylinder shape.
Other performance improvements:
- Remove unnecessary interpolation for Near and Radar objects and by extension
sensor objects.
- Use direct matrix copy instead of quaternion to synchronize orientation.
Other bug fix:
- Fix Near/Radar position error on newly activated objects. This was causing
several detection problems in YoFrankie
- Fix margin not passed correctly to gImpact shape.
- Disable force/velocity actions on static objects
This commit completes the support for modifiers in the BGE.
- The physic shape is generated according to the derived mesh.
This is true for all types of shapes and all types of
objects except soft body.
- Optimization for static derived mesh (mesh with modifiers
but no armature and no shape keys). Replicas will share
the derived mesh and the display list: less memory and
faster rendering. With this optimization, the static
derived mesh will render as fast as if the modifiers were
applied.
Known Limits:
- Sharing of mesh and display list is only possible between
in-game replicas or dupligroup. If you want to instantiate
multiple objects with modifiers, use dupligroup to ensure
best memory and GPU utilization.
- rayCast() will interact with the derived mesh as follow:
Hit position and hit normal are the real values according
to the derived mesh but the KX_PolyProxy object refers to
the original mesh. You should use it only to retrieve the
material.
- Dynamic derived mesh have very poor performance:
They use direct openGL calls for rendering (no support
for display list and vertex array) and they dont't share
the derived mesh memory. Always apply modifiers on dynamic
mesh for best performance.
- Time dependent modifiers are not supported.
- Modifiers are not supported for Bullet soft body.
Clamp objects min/max velocity.
Accessed with bullet physics from the advanced button with dynamic and rigid body objects.
- useful for preventing unstable physics in cases where objects move too fast.
- can add linear velocity with the motion actuator to give smooth motion transitions, without moving too fast.
- minimum velocity means objects don't stop moving.
- python scripts can adjust these values speedup or throttle velocity in the existing direction.
Also made copy properties from an object with no properties work (in case you want to clear all props)
This commit contains a number of performance improvements for the
BGE in the Scenegraph (parent relation between objects in the
scene) and view frustrum culling.
The scenegraph improvement consists in avoiding position update
if the object has not moved since last update and the removal
of redundant updates and synchronization with the physics engine.
The view frustrum culling improvement consists in using the DBVT
broadphase facility of Bullet to build a tree of graphical objects
in the scene. The elements of the tree are Aabb boxes (Aligned
Axis Bounding Boxes) enclosing the objects. This provides good
precision in closed and opened scenes. This new culling system
is enabled by default but just in case, it can be disabled with
a button in the World settings. There is no do_version in this
commit but it will be added before the 2.49 release. For now you
must manually enable the DBVT culling option in World settings
when you open an old file.
The above improvements speed up scenegraph and culling up to 5x.
However, this performance improvement is only visible when
you have hundreds or thousands of objects.
The main interest of the DBVT tree is to allow easy occlusion
culling and automatic LOD system. This will be the object of further
improvements.
Was adding each face with a remove doubles option that made conversion increasingly slower for larger meshes, this would often hang blender when starting with the BGE with larger meshes.
Replace btTriangleMesh()->addTriangle() with btTriangleIndexVertexArray()
YoFrankie level_1_home.blend starts a third faster, level_nut about twice as fast.
- previous commit was also incorrect using the original meshes vert locations rather then the vert locations that came from the derived mesh.
- Softbody is relying on removing doubles at 0.01 to give stable results, this no longer works but seems a bit dodgy anyway. Maybe some post-processing filter could fix up a mesh for bullet softbody.
In a simple test with ~12000 verts, overall BGE startup time went from ~4.5 sec to a bit under a second.
- before adding each vert it did a check for a duplicates.
- Using RAS_Polygon verts can give a lot of duplicates because the verts also store UV's and normals.
- Was increasing the array one item at a time, now resize the array once.
- Use the blender mesh mvert array rather then RAS_TexVert's, so needed to include some DNA headers.
In particular, the Bullet vehicle seems broken, and some soft-body demos don't work.
No new features or benefits are added yet, but a few improvements are planned before Blender 2.49 release.
Please update the build systems, and add those 3 files:
extern/bullet2/src/BulletCollision/CollisionDispatch/btActivatingCollisionAlgorithm.cpp
extern/bullet2/src/BulletCollision/CollisionDispatch/btGhostObject.cpp
extern/bullet2/src/BulletCollision/CollisionShapes/btConvexPointCloudShape.cpp
I'll watch the Blender mailing list, in case this commit causes some issues.
