Bullet physics MEL expression HELP!!

# 1 21-09-2013 , 01:30 PM

Someone that likes Maya but suffers to master it :p
Join Date: Sep 2013

Posts: 10

Hi

I have a ball in maya bullet physics, I want its velocity in (x) direction to have a certain value (-5 for example) but at frame 100

I wrote an expression for that but maya gives me error message for it:

//Error:attributes must be of float,integer , or boolean types:

what did I do wrong? is this expression correct?

if (frame <100)
bulletRigidBodyShape1.initialVelocity = << 0 , 0 , 0 >>;
else bulletRigidBodyShape1.initialVelocity = << -5 , 0 , 0 >>;

screenshot here if needed..
https://img102.imagevenue.com/img.php..._122_404lo.jpg

user added image

Last edited by black H; 21-09-2013 at 01:31 PM. Reason: correcting

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# 2 21-09-2013 , 02:09 PM

EduSciVis-er
Join Date: Dec 2005

Location: Toronto

Posts: 3,374

Try initialVelocity.x = -5 so it's not a vector.

-stwert

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Quote

# 3 21-09-2013 , 02:36 PM

Someone that likes Maya but suffers to master it :p
Join Date: Sep 2013

Posts: 10

Hi,
Yes I tried as you said bulletRigidBodyShape1.initialVelocity.x= -5;
but It gave me the same error:
//Error:attributes must be of float,integer , or boolean types:

Am not sure if the intial velocity inside bullet physics is a vector

also my MEL knowlge is soo poor, I don't have experience with , I just copy past mel codes from the net to maya user added image

I need it cause I want to make the velocity work after a certain frame in the simulation and not from the begnning

Last edited by black H; 21-09-2013 at 02:38 PM. Reason: correction

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# 4 21-09-2013 , 09:27 PM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

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.

- Genny
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