This patch introduces a simple state engine system with the logic bricks. This system features full
backward compatibility, multiple active states, multiple state transitions, automatic disabling of
sensor and actuators, full GUI support and selective display of sensors and actuators.
Note: Python API is available but not documented yet. It will be added asap.
State internals
===============
The state system is object based. The current state mask is stored in the object as a 32 bit value;
each bit set in the mask is an active state. The controllers have a state mask too but only one bit
can be set: a controller belongs to a single state. The game engine will only execute controllers
that belong to active states. Sensors and actuators don't have a state mask but are effectively
attached to states via their links to the controllers. Sensors and actuators can be connected to more
than one state. When a controller becomes inactive because of a state change, its links to sensors
and actuators are temporarily broken (until the state becomes active again). If an actuator gets isolated,
i.e all the links to controllers are broken, it is automatically disabled. If a sensor gets isolated,
the game engine will stop calling it to save CPU. It will also reset the sensor internal state so that
it can react as if the game just started when it gets reconnected to an active controller. For example,
an Always sensor in no pulse mode that is connected to a single state (i.e connected to one or more
controllers of a single state) will generate a pulse each time the state becomes active. This feature is
not available on all sensors, see the notes below.
GUI
===
This system system is fully configurable through the GUI: the object state mask is visible under the
object bar in the controller's colum as an array of buttons just like the 3D view layer mask.
Click on a state bit to only display the controllers of that state. You can select more than one state
with SHIFT-click. The All button sets all the bits so that you can see all the controllers of the object.
The Ini button sets the state mask back to the object default state. You can change the default state
of object by first selecting the desired state mask and storing using the menu under the State button.
If you define a default state mask, it will be loaded into the object state make when you load the blend
file or when you run the game under the blenderplayer. However, when you run the game under Blender,
the current selected state mask will be used as the startup state for the object. This allows you to test
specific state during the game design.
The controller display the state they belong to with a new button in the controller header. When you add
a new controller, it is added by default in the lowest enabled state. You can change the controller state
by clicking on the button and selecting another state. If more than one state is enabled in the object
state mask, controllers are grouped by state for more readibility.
The new Sta button in the sensor and actuator column header allows you to display only the sensors and
actuators that are linked to visible controllers.
A new state actuator is available to modify the state during the game. It defines a bit mask and
the operation to apply on the current object state mask:
Cpy: the bit mask is copied to the object state mask.
Add: the bits that set in the bit mask will be turned on in the object state mask.
Sub: the bits that set in the bit mask will be turned off in the object state mask.
Inv: the bits that set in the bit mask will be inverted in the objecyy state mask.
Notes
=====
- Although states have no name, a simply convention consists in using the name of the first controller
of the state as the state name. The GUI will support that convention by displaying as a hint the name
of the first controller of the state when you move the mouse over a state bit of the object state mask
or of the state actuator bit mask.
- Each object has a state mask and each object can have a state engine but if several objects are
part of a logical group, it is recommended to put the state engine only in the main object and to
link the controllers of that object to the sensors and actuators of the different objects.
- When loading an old blend file, the state mask of all objects and controllers are initialized to 1
so that all the controllers belong to this single state. This ensures backward compatibility with
existing game.
- When the state actuator is activated at the same time as other actuators, these actuators are
guaranteed to execute before being eventually disabled due to the state change. This is useful for
example to send a message or update a property at the time of changing the state.
- Sensors that depend on underlying resource won't reset fully when they are isolated. By the time they
are acticated again, they will behave as follow:
* keyboard sensor: keys already pressed won't be detected. The keyboard sensor is only sensitive
to new key press.
* collision sensor: objects already colliding won't be detected. Only new collisions are
detected.
* near and radar sensor: same as collision sensor.
Armatures are back
Split screen
Double sided lightning
Ambient lighting
Alpha test
Material IPO support (one per object atm)
Blender materials
GLSL shaders - Python access
Up to three texture samplers from the material panel ( 2D & Cube map )
Python access to a second set of uv coordinates
See http://www.elysiun.com/forum/viewtopic.php?t=58057
from brian hayward (bthayward)
Detailed description:
Currently, when an armature deformed object's mesh is replaced by the ReplaceMesh actuator, the new mesh fails to deform to the armature's movement.
My patch fixes this by properly replacing the deform controller along with the mesh (when appropriete).
For instance, if one had an animated character using any of the standard deformation techniques (armature, ipo, RVK, or AVK), that character's mesh would currently be prevented from changing mid-game. It could be replaced, but the new mesh would lack the controller which tells it how to deform. If one wanted to dynamiclly add a hat on top of the character's head, it would require storing a secondary prebuilt character (mesh, armature, logic, ect...) on another layer FOR EACH HAT the character could possibly wear, then swapping out the whole character when the hat change was desired. So if you had 4 possible hat/character combos, you would have 4 character meshes, 4 armatures, 4 sets of logic, and so on. I find this lack of flexibility to be unresonable.
With my patch, one could accomplish the same thing mearly by making one version of the character in the main layer, and adding an invisible object atop the character's head (which is parented to the head bone). Then whenever it becomes desirable, one can replace the invisible object's mesh with the desirable hat's mesh, then make it visible. With my patch, the hat object would then continue to deform to the character's head regardless of which hat was currently being worn.
*note 1*
for armature/mesh deformations, the new mesh must have properly assigned vertex groups which match one or more of the bones of the target armature before the replaceMesh call is made. Otherwise the vertices won't react to the armature because they won't know how. (not sure if vertices can be scripted to change groups after the game has started)
*note 2*
The added processing time involved with replacing the object's deform controller is negligible.
Keyboard sensors can now hook escape key. Ctrl-Break can be used from within blender if you've forgotten an end game actuator.
Fixed a stupid bug preventing some actuators working (like TrackTo).
[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.
