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.
Use each types dictionary to store attributes PyAttributeDef's so it uses pythons hash lookup (which it was already doing for methods) rather then doing a string lookup on the array each time.
This also means attributes can be found in the type without having to do a dir() on the instance.
- Initialize python types with PyType_Ready, which adds methods to the type dictionary.
- use Pythons get/setattro (uses a python string for the attribute rather then char*). Using basic C strings seems nice but internally python converts them to python strings and discards them for most functions that accept char arrays.
- Method lookups use the PyTypes dictionary (should be faster then Py_FindMethod)
- Renamed __getattr -> py_base_getattro, _getattr -> py_getattro, __repr -> py_base_repr, py_delattro, py_getattro_self etc.
From here is possible to put all the parent classes methods into each python types dictionary to avoid nested lookups (api has 4 levels of lookups in some places), tested this but its not ready yet.
Simple tests for getting a method within a loop show this to be between 0.5 and 3.2x faster then using Py_FindMethod()
Added the method into the PyType so python knows about the methods (its supposed to work this way).
This means in the future the api can use PyType_Ready() to store the methods in the types dictionary.
Python3 removes Py_FindMethod and we should not be using it anyway since its not that efficient.
Python dir(ob) for game types now includes attributes names,
* Use "__dict__" rather then "__methods__" attribute to be Python 3.0 compatible
* Added _getattr_dict() for getting the method and attribute names from a PyObject, rather then building it in the macro.
* Added place holder *::Attribute array, needed for the _getattr_up macro.
Removed a check in Python API touch.setProperty() for the property name on the sensor owner before allowing the name to be set - it makes no sense and isnt checked when creating the sensor.
- SCA_DelaySensor.py indent error making epydoc fail.
Previously only the first collision would trigger an event (no collisions a negative event ofcourse)
With the Pulse option enabled, any change to the set of colliding objects will trigger an event.
Added this because there was no way to count how many sheep were on a platform in YoFrankie without running a script periodically.
Changes in collision are detected by comparing the number of objects colliding with the last event, as well as a hash made from the object pointers.
Also changed the touch sensors internal list of colliding objects to only contain objects that match the property or material.
- pulse isnt a great name, could change this.
- variables that shadow vers declared earlier
- Py_Fatal print an error to the stderr
- gcc was complaining about the order of initialized vars (for classes)
- const return values for ints and bools didnt do anything.
- braces for ambiguous if statements
Use 'const char *' rather then the C++ 'STR_String' type for the attribute identifier of python attributes.
Each attribute and method access from python was allocating and freeing the string.
A simple test with getting an attribute a loop shows this speeds up attribute lookups a bit over 2x.
- Forgot to make SCA_ISensor::UnregisterToManager() virtual to intercept active-inactive transition on collision sensor to clear colliders reference.
- Don't record collision on inactive sensor.
This situation occurs when an object with an inactive collision sensor collides with an object with an active collision sensor: the collision handler triggers both sensors.
The result of this bug was pending references that eventually cause temporary memory leak (until the sensor is reactivated).
Implementation of the PHY_IPhysicsController::SetMargin(),
GetMargin(), SetRadius() and GetRadius() for Bullet and Sumo
to allow resetting the Near sensor radius. For bullet use
the new setUnscaledRadius() function to change sphere radius.
In pPreparation of a Fh constraint actuator:
- Add KX_IPhysicsController::GetRadius()
- Fix implementation of KX_BulletPhysicsController::GetVelocity()
(velocity at a point in geometric coordinate)
- Don't try to set velocity on static object (Bullet will assert)
- Add KX_GameObject::GetVelocity() for C access to local velocity
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.
General
=======
- Removal of Damp option in motion actuator (replaced by
Servo control motion).
- No PyDoc at present, will be added soon.
Generalization of the Lvl option
================================
A sensor with the Lvl option selected will always produce an
event at the start of the game or when entering a state or at
object creation. The event will be positive or negative
depending of the sensor condition. A negative pulse makes
sense when used with a NAND controller: it will be converted
into an actuator activation.
Servo control motion
====================
A new variant of the motion actuator allows to control speed
with force. The control if of type "PID" (Propotional, Integral,
Derivate): the force is automatically adapted to achieve the
target speed. All the parameters of the servo controller are
configurable. The result is a great variety of motion style:
anysotropic friction, flying, sliding, pseudo Dloc...
This actuator should be used in preference to Dloc and LinV
as it produces more fluid movements and avoids the collision
problem with Dloc.
LinV : target speed as (X,Y,Z) vector in local or world
coordinates (mostly useful in local coordinates).
Limit: the force can be limited along each axis (in the same
coordinates of LinV). No limitation means that the force
will grow as large as necessary to achieve the target
speed along that axis. Set a max value to limit the
accelaration along an axis (slow start) and set a min
value (negative) to limit the brake force.
P: Proportional coefficient of servo controller, don't set
directly unless you know what you're doing.
I: Integral coefficient of servo controller. Use low value
(<0.1) for slow reaction (sliding), high values (>0.5)
for hard control. The P coefficient will be automatically
set to 60 times the I coefficient (a reasonable value).
D: Derivate coefficient. Leave to 0 unless you know what
you're doing. High values create instability.
Notes: - This actuator works perfectly in zero friction
environment: the PID controller will simulate friction
by applying force as needed.
- This actuator is compatible with simple Drot motion
actuator but not with LinV and Dloc motion.
- (0,0,0) is a valid target speed.
- All parameters are accessible through Python.
Distance constraint actuator
============================
A new variant of the constraint actuator allows to set the
distance and orientation relative to a surface. The controller
uses a ray to detect the surface (or any object) and adapt the
distance and orientation parallel to the surface.
Damp: Time constant (in nb of frames) of distance and
orientation control.
Dist: Select to enable distance control and set target
distance. The object will be position at the given
distance of surface along the ray direction.
Direction: chose a local axis as the ray direction.
Range: length of ray. Objecgt within this distance will be
detected.
N : Select to enable orientation control. The actuator will
change the orientation and the location of the object
so that it is parallel to the surface at the vertical
of the point of contact of the ray.
M/P : Select to enable material detection. Default is property
detection.
Property/Material: name of property/material that the target of
ray must have to be detected. If not set, property/
material filter is disabled and any collisioning object
within range will be detected.
PER : Select to enable persistent operation. Normally the
actuator disables itself automatically if the ray does
not reach a valid target.
time : Maximum activation time of actuator.
0 : unlimited.
>0: number of frames before automatic deactivation.
rotDamp: Time constant (in nb of frame) of orientation control.
0 : use Damp parameter.
>0: use a different time constant for orientation.
Notes: - If neither N nor Dist options are set, the actuator
does not change the position and orientation of the
object; it works as a ray sensor.
- The ray has no "X-ray" capability: if the first object
hit does not have the required property/material, it
returns no hit and the actuator disables itself unless
PER option is enabled.
- This actuator changes the position and orientation but
not the speed of the object. This has an important
implication in a gravity environment: the gravity will
cause the speed to increase although the object seems
to stay still (it is repositioned at each frame).
The gravity must be compensated in one way or another.
the new servo control motion actuator is the simplest
way: set the target speed along the ray axis to 0
and the servo control will automatically compensate
the gravity.
- This actuator changes the orientation of the object
and will conflict with Drot motion unless it is
placed BEFORE the Drot motion actuator (the order of
actuator is important)
- All parameters are accessible through Python.
Orientation constraint
======================
A new variant of the constraint actuator allows to align an
object axis along a global direction.
Damp : Time constant (in nb of frames) of orientation control.
X,Y,Z: Global coordinates of reference direction.
time : Maximum activation time of actuator.
0 : unlimited.
>0: number of frames before automatic deactivation.
Notes: - (X,Y,Z) = (0,0,0) is not a valid direction
- This actuator changes the orientation of the object
and will conflict with Drot motion unless it is placed
BEFORE the Drot motion actuator (the order of
actuator is important).
- This actuator doesn't change the location and speed.
It is compatible with gravity.
- All parameters are accessible through Python.
Actuator sensor
===============
This sensor detects the activation and deactivation of actuators
of the same object. The sensor generates a positive pulse when
the corresponding sensor is activated and a negative pulse when
it is deactivated (the contrary if the Inv option is selected).
This is mostly useful to chain actions and to detect the loss of
contact of the distance motion actuator.
Notes: - Actuators are disabled at the start of the game; if you
want to detect the On-Off transition of an actuator
after it has been activated at least once, unselect the
Lvl and Inv options and use a NAND controller.
- Some actuators deactivates themselves immediately after
being activated. The sensor detects this situation as
an On-Off transition.
- The actuator name can be set through Python.
- default the m_edgecode to 65535, the wireframe was invisible. when is the edgecode available again ?
- added an extra condition, nearsensor is not yet working for bullet, but it crashed.
alone with the following flags :
-Wall -Wno-char-subscripts -Wno-missing-braces.
the only one still worrying me is in rand.c line 57 :
rand.c:57: integer constant is too large for "long" type
but i have no clue about how correct cross-compiler and 32/64 bits friendly
see also my mail to commiter list for signed/unsigned issues
Consider:
gameobj->getClientInfo()->m_auxilary_info = (matname ? (void*)(matname+2) : NULL);
It works if matname is "MAblah", but not if matname is "".
2. Added constructor for struct RAS_CameraData.
3. Added initializers to the struct KX_ClientObjectInfo constructor
4. Collision sensors won't detect near sensors.
5. A stack of minor tweaks, adjusting whitespace, using ++it for stl stuff.
[SCons] Build with Solid as default when enabling the gameengine in the build process
[SCons] Build solid and qhull from the extern directory and link statically against them
That was about it.
There are a few things that needs double checking:
* Makefiles
* Projectfiles
* All the other systems than Linux and Windows on which the build (with scons) has been successfully tested.
