AimConstraint

[Richter Belmont]

The AimConstraint is a constraint that will rotate an object so that it's "aim" at a given target.
It go like this:
The object rotate on the two non-aiming axis, so that its aim axis point toward the target.
Then the object rotate on the aim axis, so its up vector axis point toward the up target.

Node able to use AimConstraint are TTransform and object that have access to all the parameter of it (like Tjoint).
In the TTransform node that you want to add some AimConstraint, you will add this parameter: TBaseTransform.ConstraintArray [ ]; and inside the [ ] of it, you link some AimConstraint node object.
Example:
 

Code:

TBaseTransform.ConstraintArray [ AimConstraint :local_exemple_aimConstraint ];[/color]

[color=#000000]AimConstraint :local_exemple_aimConstraint . {[/color]
[color=#000000]AimConstraint.AimVector Vector3f( 0, 0, 1 );[/color]
[color=#000000]AimConstraint.UpVector Vector3f( 1, 0, 0 );[/color]
[color=#000000]AimConstraint.UpTarget TTransform :local_myUpTarget;[/color]
[color=#000000]Constraint.TargetArray [ TTransform :local_myTarget ];[/color]
[color=#000000]Constraint.WeightArray Array_F32 [ 1];[/color]
[color=#000000]Object.Name "exemple_aimConstraint";[/color]
[color=#000000]};

AimConstraint.AimVector Vector3f( X, Y, Z );
The axis of your object use to aim.
There is only 6 possible value: ( -1, 0, 0 ), ( 1, 0, 0 ), ( 0, -1, 0 ), ( 0, 1, 0 ), ( 0, 0, -1 ), ( 0, 0, 1 )

AimConstraint.UpVector Vector3f( X, Y, Z );
Axis of your object use to give little bit more precision to the result rotation.
There is only 4 possible value: ( -1, 0, 0 ), ( 1, 0, 0 ), ( 0, -1, 0 ), ( 0, 1, 0 ), ( 0, 0, -1 ), ( 0, 0, 1 )
You cannot use the same axis as the AimVector. (this is why I said 4 instead of 6)

AimConstraint.UpTarget
The object that your object UpVector axis should point toward to.
If no UpTarget is provided ( = this parameter isn't use), the scene Y axis will be use instead.

Constraint.TargetArray [ ];
Inside the [ ] of this parameter, you will link the TTransform node that your object will aim at.
Exemple:
 

Code:

Constraint.TargetArray [ TTransform :local_butt_L_joint01_Constraint_Locator , TTransform :local_butt_R_joint01_Constraint_Locator ];

This parameter appear to only support TTransform node, if you want to aim at a TJoint, you will need to create a new TTransform that will use the given Tjoint as parent, and link this newly created TTransform in the array.

Constraint.WeightArray Array_F32 [ ];
For each item linked in the Constraint.TargetArray [ ]; parameter, you will write a number going from 0 to 1 inside [ ] of the Constraint.WeightArray Array_F32 [ ]; parameter.
These number tell the influence of each linked TTransform (0 = no influence, 1 = 100% influence)
Exemple:

Code:

Constraint.WeightArray Array_F32 [ 0.5, 0.5];

AimConstraint.OrientOffset Vector3f( X, Y, Z );
Ajust the rotation offset of the AimConstraint.
You should not need to.

AimConstraint.UpTargetVector Vector3f( X, Y, Z );
Just to let you know AimConstraint also have this parameter, but I have no idea what it do.
All the AimConstraint of the default game having this parameter seem to use the value ( 0, 0, 0 ) for it.

AimConstraint.Twist F32(X);
Ajust the twist value of the AimConstraint.
I don' really see why someone may need to do it.

Note: UpVector/UpTarget use the word Up, but they don't need/are necessary being "up".