The Physics button controls the creation of a physics representation
of the object when starting the game. If the button is not selected,
the object is a pure graphical object with no physics representation
and all the other physics buttons are hidden.
Selecting this button gives access to the usual physics buttons.
The physics button is enabled by default to match previous Blender
behavior.
The margin parameter allows to control the collision margin from
the UI. Previously, this parameter was only accessible through
Python. By default, the collision margin is set to 0.0 on static
objects and 0.06 on dynamic objects.
To maintain compatibility with older games, the collision margin
is set to 0.06 on all objects when loading older blend file.
Note about the collision algorithms in Bullet 2.71
--------------------------------------------------
Bullet 2.71 handles the collision margin differently than Bullet 2.53
(the previous Bullet version in Blender). The collision margin is
now kept "inside" the object for box, sphere and cylinder bound
shapes. This means that two objects bound to any of these shape will
come in close contact when colliding.
The static mesh, convex hull and cone shapes still have their
collision margin "outside" the object, which leaves a space of 1
or 2 times the collision margin between objects.
The situation with Bullet 2.53 was more complicated, generally
leading to more space between objects, except for box-box collisions.
This means that running a old game under Bullet 2.71 may cause
visual problems, especially if the objects are small. You can fix
these problems by changing some visual aspect of the objects:
center, shape, size, position of children, etc.
the features that are needed to run the game. Compile tested with
scons, make, but not cmake, that seems to have an issue not related
to these changes. The changes include:
* GLSL support in the viewport and game engine, enable in the game
menu in textured draw mode.
* Synced and merged part of the duplicated blender and gameengine/
gameplayer drawing code.
* Further refactoring of game engine drawing code, especially mesh
storage changed a lot.
* Optimizations in game engine armatures to avoid recomputations.
* A python function to get the framerate estimate in game.
* An option take object color into account in materials.
* An option to restrict shadow casters to a lamp's layers.
* Increase from 10 to 18 texture slots for materials, lamps, word.
An extra texture slot shows up once the last slot is used.
* Memory limit for undo, not enabled by default yet because it
needs the .B.blend to be changed.
* Multiple undo for image painting.
* An offset for dupligroups, so not all objects in a group have to
be at the origin.
HELP BUILD SYSTEM MAINTAINERS: Please help with updating all build systems: the newly added files need to be added. Note that the src/SoftBody has been added for future extension of real-time soft bodies.
rayCast(to,from,dist,prop,face,xray,poly):
The face paremeter determines the orientation of the normal:
0 or omitted => hit normal is always oriented towards the ray origin (as if you casted the ray from outside)
1 => hit normal is the real face normal (only for mesh object, otherwise face has no effect)
The ray has X-Ray capability if xray parameter is 1, otherwise the first object hit (other than self object) stops the ray.
The prop and xray parameters interact as follow:
prop off, xray off: return closest hit or no hit if there is no object on the full extend of the ray.
prop off, xray on : idem.
prop on, xray off: return closest hit if it matches prop, no hit otherwise.
prop on, xray on : return closest hit matching prop or no hit if there is no object matching prop on the full extend of the ray.
if poly is 0 or omitted, returns a 3-tuple with object reference, hit point and hit normal or (None,None,None) if no hit.
if poly is 1, returns a 4-tuple with in addition a KX_PolyProxy as 4th element.
The KX_PolyProxy object holds information on the polygon hit by the ray: the index of the vertex forming the poylgon, material, etc.
Attributes (read-only):
matname: The name of polygon material, empty if no material.
material: The material of the polygon
texture: The texture name of the polygon.
matid: The material index of the polygon, use this to retrieve vertex proxy from mesh proxy
v1: vertex index of the first vertex of the polygon, use this to retrieve vertex proxy from mesh proxy
v2: vertex index of the second vertex of the polygon, use this to retrieve vertex proxy from mesh proxy
v3: vertex index of the third vertex of the polygon, use this to retrieve vertex proxy from mesh proxy
v4: vertex index of the fourth vertex of the polygon, 0 if polygon has only 3 vertex
use this to retrieve vertex proxy from mesh proxy
visible: visible state of the polygon: 1=visible, 0=invisible
collide: collide state of the polygon: 1=receives collision, 0=collision free.
Methods:
getMaterialName(): Returns the polygon material name with MA prefix
getMaterial(): Returns the polygon material
getTextureName(): Returns the polygon texture name
getMaterialIndex(): Returns the material bucket index of the polygon.
getNumVertex(): Returns the number of vertex of the polygon.
isVisible(): Returns whether the polygon is visible or not
isCollider(): Returns whether the polygon is receives collision or not
getVertexIndex(vertex): Returns the mesh vertex index of a polygon vertex
getMesh(): Returns a mesh proxy
New methods of KX_MeshProxy have been implemented to retrieve KX_PolyProxy objects:
getNumPolygons(): Returns the number of polygon in the mesh.
getPolygon(index): Gets the specified polygon from the mesh.
More details in PyDoc.
The root cause of this bug is the fact that Bullet shapes
are shared between duplicated game objects. As the physics
object scale is stored in the shape, all duplicas must
have the same scale otherwise the physics representation
is incorrect.
This fix introduces a mechanism to duplicate shapes at
runtime so that Bullet shapes are not shared anymore.
The drawback is an increased memory consuption.
A reference count mechanism will be introduced in a
later revision to keep Bullet shape shared between
duplicas that have the same scale.
With this patch, only sensors that are connected to
active states are actually registered in the logic
manager. Inactive sensors won't take any CPU,
especially the Radar and Near sensors that use a
physical object for the detection: these objects
are removed from the physics engine.
To take advantage of this optimization patch, you
need to define very light idle state when the
objects are inactive: make them transparent, suspend
the physics, keep few sensors active (e,g a message
sensor to wake up), etc.
First batch of optimizaton of the bullet adaptation layer in the BGE.
- remove circular motion state update.
- optimization of physic adaptation layer for bullet: bypass
unecessary conversion of rotation matrix to quaternion and back.
- remove double updates during object replication.
The error was causing by the KINEMATIC flag not set automatically when the linear or angular velocity was set on static objects. Note that these actuators still won't work on static objects: the crash is fixed but not the actuator; linV and angV only work on dynamic objects. Fixing the linV and angV actuators on static object requires a bit more reflexion. For the time being, use dRot and dLoc on static objects.
Cleaned the code a bit: added systematic check on the physic controller presence before taking action.
Note: Visual Studio projectfiles and other buildsystems need to add extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp to the project!
