Simply Maya User Community - View Single Post - Bullet physics MEL expression HELP!!

You'll have to use the "setAttr" command in this case and specify what kind of data. This attribute takes three float values, it's easy to find out just enter this into the command line:

Code:

getAttr -type bulletRigidBodyShape1.initialVelocity;

and the result will be:

Code:

// Result: float3 //

Using the type flag ensures Maya won't misinterpret the code and throw a syntax error

Code:

if(frame<100)

	setAttr bulletRigidBodyShape1.initialVelocity -type float3 1.000 2.000 3.000;
else 
	setAttr bulletRigidBodyShape1.initialVelocity -type float3 0.000 0.000 0.000;

Hope that helped.