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pointAt

Usage

member(whichCastmember).model(whichModel).pointAt(vectorPosition{, vectorUp})
member(whichCastmember).camera(whichCamera).pointAt(vectorPosition{, vectorUp})
member(whichCastmember).light(whichLight).pointAt(vectorPosition{, vectorUp})
member(whichCastmember).group(whichGroup).pointAt(vectorPosition{, vectorUp})	

            

            

            

            

Description

3D command; rotates the referenced object so that its forward direction vector points at a specified world relative position, then it rotates the referenced object to point it’s up direction vector in the direction hinted at by a specified relative vector.

The object’s front and up direction vectors are defined by the object’s pointAtOrientation property.

Parameters

vectorPosition Required. Specifies the world relative position. This value can also be a node reference.

vectorUp Optional. Specfies a world relative vector that hints at where the object’s up vector should point. If this parameter isn’t specified, then pointAt defaults to using the world’s y axis as the up hinting vector. If you attempt to point the object at a position such that the object’s forward vector is parallel to the world’s y axis, then the world’s x axis is used as the up hinting vector. The direction at which you wish to point the object’s forward direction and the direction specified by vectorUp do not need to be perpendicular to each other being as this command only uses the vectorUp parameter as a hinting vector.

Example

This example points three objects at the model named Mars: the camera named MarsCam, the light named BrightSpot, and the model named BigGun:

thisWorldPosn = member("Scene").model("Mars").worldPosition
member("Scene").camera("MarsCam").pointAt(thisWorldPosn)
member("Scene").light("BrightSpot").pointAt(thisWorldPosn)
member("Scene").model("BigGun").pointAt(thisWorldPosn, vector(0,0,45))

            

            

            

            

            

            

            

            

If you use non-uniform scaling and a custom pointAtOrientation on the same node, e.g., a model, using pointAt will likely cause unexpected non-uniform scaling. This is due to the order in which the non-uniform scaling and the rotation to properly orient the node are applied. To workaround this issue, do one of the following:

• Avoid using non-uniform scaling and non-default pointAtOrientation together on the same node.
• Remove your scale prior to using pointAt, and then reapply it afterwards.

  For example:

  scale = node.transform.scale
  node.scale = vector( 1, 1, 1 )
  node.pointAt(vector(0, 0, 0)) -- non-default pointAtOrientation
  node.transform.scale = scale
  
                          
  
                          
  
                          
  
   
  
                          
  
                          
  
                          
  
                          

pointAtOrientation

Usage

member(whichCastmember).model(whichModel).pointAtOrientation
member(whichCastmember).group(whichGroup).pointAtOrientation
member(whichCastmember).light(whichLight).pointAtOrientation
member(whichCastmember).camera(whichCamera).pointAtOrientation

                

                

                

                

                

                

                

                

Description

3D model, light, group and camera property; allows you to get or set how the referenced object responds to the pointAt command. This property is a linear list of two object-relative vectors, the first vector in the list defines which direction is considered the object’s front direction, the second defines which direction is considered the object’s up direction.

The object’s front and up directions do not need to be perpendicular to each other, but they should not be parallel to each other.

Example

This statement displays the object-relative front direction and up direction vectors of the model named bip01:

put member("scene").model("bip01").pointAtOrientation
-- [vector(0.0000, 0.0000, 1.0000), vector(0.0000, 1.0000, 0.0000)]

                

                

                

                

                

                

                

                

See also

pointOfContact

Usage

collisionData.pointOfContact

                

                

                

                

                

                

                

                

Description

3D collisionData property; returns a vector describing the point of contact in a collision between two models.

The collisionData object is sent as an argument with the #collideWith and #collideAny events to the handler specified in the registerForEvent, registerScript, and setCollisionCallback commands.

The #collideWith and #collideAny events are sent when a collision occurs between models to which collision modifiers have been added. The resolve property of the models’ modifiers must be set to TRUE.

This property can be tested but not set.

Example

This example has two parts. The first part is the first line of code, which registers the #explode handler for the #collideAny event. The second part is the #explode handler. When two models in the cast member MyScene collide, the #explode handler is called and the collisionData argument is sent to it. The first nine lines of the #explode handler create the model resource named SparkSource and set its properties. This model resource is a single burst of particles. The tenth line of the handler creates a model named SparksModel using the model resource named SparkSource. The last line of the handler sets the position of SparksModel to the position where the collision occurred. The overall effect is a burst of sparks caused by a collision.

member("MyScene").registerForEvent(#collideAny, #explode, 0)

on explode me, collisionData
  nmr = member("MyScene").newModelResource("SparkSource",  #particle)
  nmr.emitter.mode = #burst
  nmr.emitter.loop = 0
  nmr.emitter.minSpeed = 30
  nmr.emitter.maxSpeed = 50
  nmr.emitter.direction = vector(0, 0, 1)
  nmr.colorRange.start = rgb(0, 0, 255)
  nmr.colorRange.end = rgb(255, 0, 0)
  nmr.lifetime = 5000
  nm = member("MyScene").newModel("SparksModel", nmr)
  nm.transform.position = collisionData.pointOfContact
end

                

                

                

                

                

                

                

                

See also

modelA, modelB

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