Maya Instancer

Instancer Nodes:

This is where you can select which instancer node is associated with your particle object.

Allow All Data Types:

Sometimes you will want to scale an object proportionally with a float value. But since scale is a vector <<X,Y,Z>> number, you will not see custom float attributes listed. If you wish to use a float of say 5 that is assigned to all three vector positions <<5,5,5>>, check this box and you will see your custom float attribute in the drop-down list. Otherwise, the dropdown list for scale only shows custom attributes created as vectors. This check box affects all of the following drop-down lists.

Position: (vector)

This is where you can change the way Maya views your instanced object in relation to its pivot point. The default is worldPosition and Maya interprets these values in the local space of the instanced geometry. This is why it is important to have your object read <<0,0,0>> for its transform when the pivot point is placed at the origin. If your object has different values, you will need to freeze its transform to reset these values. While you can change this, it is best to leave it set at worldPosition to eliminate any possible confusion or strange results in your animation.

Scale: (vector)

This is where you can tell Maya how you want to have the scale of your objects affected. The default scale is <<1,1,1>>. Here you can create a custom attribute to change the scale of your instanced geometry. For instance you may want to create an asteroid field of randomly scaled rocks. You can instance one single rock and write the following creation expression for a float custom_scale. particleShape.custom_scale = rand(.75,1.5); Then when you assign the custom_scale attribute from the scale drop-down you will have your emitter creating randomly scaled rocks. But remember to check the box for “Allow All Data Types” since your expression generates a float number while Scale is a vector value.