Orx Learning

Allows the creation and handling of physical bodies. They are used as a container with associated properties. Bodies are used by objects. They thus can be referenced by objects as structures.

[BodyTemplate]
Inertia        = <float>
Mass           = <float>
LinearDamping  = <float>
AngularDamping = <float>
FixedRotation  = <bool>
HighSpeed      = <bool>
Dynamic        = <bool>
CustomGravity  = <vector>
AllowSleep     = <bool>
AllowMoving    = <bool>
PartList       = BodyPartTemplate1 # ... # BodyPartTemplateN

[BodyPartSphereTemplate]
Type        = sphere
Center      = <vector> | full
Radius      = <float> | full
CheckMask   = <16b flags>
SelfFlags   = <16b flags>
Density     = <float>
Friction    = <float>
Restitution = <float>
Solid       = <bool>

[BodyPartBoxTemplate]
Type        = box
TopLeft     = <vector> | full
BottomRight = <vector> | full
CheckMask   = <16b flags>
SelfFlags   = <16b flags>
Density     = <float>
Friction    = <float>
Restitution = <float>
Solid       = <bool>

[BodyPartMeshTemplate]
Type        = mesh
VertexList  = <vector>#<vector>#...
CheckMask   = <16b flags>
SelfFlags   = <16b flags>
Density     = <float>
Friction    = <float>
Restitution = <float>
Solid       = <bool>

[BodyPartEdgeTemplate]
Type           = edge
VertexList     = <vector>
PreviousVertex = <vector>
NextVertex     = <vector>
Friction       = <float>
Restitution    = <float>
Density        = <float>
SelfFlags      = flags
CheckMask      = flags
Solid          = <bool>

Here's a list of the available properties for an orxBODY structure:

• PartList: List of all the parts that will compose a body. There's no limit on the number of parts that can be defined for a single body. This property needs to be defined if you want it to collide with other bodies.
• AngularDamping: Damping of angular velocity for this body. By default its value is 0.0, which means no damping.
• CustomGravity: Defines a gravity vector to use for this body instead of the world's one. By default it doesn't exist, which means world's gravity will be used for this body.
• Dynamic: Defines if this body should be dynamic or static. If your object is expected to move, this property should be set to true. Static bodies can't collide with other static bodies. By default, its value is false (ie. static).
• FixedRotation: Defines if your dynamic object is allowed to rotate as a result of collision forces. By default its value is false which means it can rotate freely.
• HighSpeed: For high velocity objects (like bullets), this property should be set to true to avoid collision errors. However, every object flagged as HighSpeed will cost more when processed by the physics engine. By default its value is false.
• Inertia: Defines an inertia value for this body. By default its value is 0.0.
• LinearDamping: Damping of speed (linear velocity) for this body. By default its value is 0.0, which means no damping.
• Mass: Defines a mass, in kg, for this body. If parts are defined, the mass will be overridden by an automatically calculated value based of parts' sizes and positions.
• AllowMoving: This is only used by static bodies. If set to true, the static body can be moved via its speed/angular velocity accessors. Defaults to true.
• AllowSleep: Defaults to true.

Here's a list of the available properties for all types of body parts:

• Type: Defines the type of the body part. Available types are sphere, box and mesh (ie. convex polygon). This property needs to be defined.
• CheckMask/SelfFlags: Both properties are flags expressed on 16bits. The SelfFlags defines this part identity whereas the CheckMask defines which parts are allowed to collide with it. For a collision to happen between two parts the expressions (Part1.CheckMask & Part2.SelfFlags) and (Part2.CheckMask & Part1.SelfFlags) have both to evaluate to true. NB: Two parts of the same body won't collide whichever CheckMask/SelfFlags they have. ¹⁾
• Density: Defines the density of this part, an influences the body's mass. Its default value is 1.0.
• Friction/Restitution: Define the friction and restitution of this part, usually between 0.0 and 1.0. ²⁾ By default both their values are 0.0. Restitution is how much “Bounce” an object has.
• Solid: Defines if this part is solid or not. Only solid parts will trigger a reaction on their body when colliding with others. By default its value is false which means the collision info will be signaled through events, but the physics simulation of this body won't be automatically affected by it.

Here's a list of the available properties only available to sphere parts:

• Center: Defines the center of the sphere (in 2D it's a circle, of course) in the parent's space (ie. in object's space). By default its value is full which means the center will match the object's one (ie. the center of its current graphic).
• Radius: Defines the radius of the sphere (or 2D circle). By default its value is full which means the sphere's radius will match the biggest dimension of the parent object. You can find an example in the spawner tutorial ³⁾.

Here's a list of the available properties only available to box parts:

• TopLeft/BottomRight: Define the extrema of the box (in 2D it's a rectangle, of course) in the parent's space (ie. in object's space). By default their values are full which means TopLeft and BottomRight will match the full rectangle defined by the parent object's current graphic. You can find an example in the physics tutorial.

Here's a list of the available properties only available to mesh ⁴⁾ parts:

• VertexList: Provides a list of vertex coordinates in parent object's space. The resulting polygon needs to be convex. Up to 8 vertices can be defined and they have to be entered clockwise. You can find an example in the spawner tutorial ⁵⁾.

• VertexList: This should contain exactly 2 vectors.
• PreviousVertex: Optional previous ghost vertex.
• NextVertex: Optional next ghost vertex.

• VertexList: This should contain at least 2 vectors.
• PreviousVertex: Optional previous ghost vertex.
• NextVertex: Optional next ghost vertex.
• Loop: If true, the chain will be treated as a closed loop. Defaults to false.