Random expression question

[davus]

I'm sure the answer is simple but i can't seem to find it. All I want to do is not have the random function reevaluate each frame.

For Example:

nurbsSphere1.translateX = rand(1,100);

 I'd like that sphere to be placed randomly between 1 and 100, however I DO NOT want it to reevaluate on the next frame. The translation channel is just an example, sometimes I'd like that to happen in the frame extension of a texture, position on a motion path, etc.

Really appreciate any help. I should also note that I'm not very good in mel, I only know enough to get myself into trouble, so if any answers could be clearly explained it would be greatly appreciated. Thank Q!   -DD 

[molemansd7]

It looks like what you're setting up there is an expression command. This would be evaluated on everyframe, as that's the nature of an expression. If you're just wanting to do this once, randomly, you should just use the move command. You could do it as follows:

move rand 1 100 rand 1 100rand 1 100 nurbsSphere1;

That will give you a random x y and z position. Or, you could simply assing a single random result to a variable and and use taht for all x y and z coordinates. This would result in, say 23,23,23 as a position.

The ` marks tell Maya to execute what is in between them, and return the result... so if I were to say:

int $randNumber = rand 1 100;

Then $randNumber would be an integer between 1 and 100. Then I could say:

move $randNumber $randNumber $randNumber nurbSphere1;

and it would move to that location. In the first example, I just didn't feel like making it a separate varialble. Make sense?

[davus]

Thanx so much, yes that makes total sense. So how about in the frame offset example where I'm not actually moving anything but rather trying to set the offset to a random number... is there another function for that type of instance?

-DD 

[davus]

Nevermind!!!  I just figured it out! I know its simple, but its really satisfying to figure something out... thanks for all your help!

This is what i came up with:

setAttr "psdFileTex1.frameOffset" rand 0 300;

So why this all came up was i was trying to save some time while loading some textures. I had a couple hundred textures and it would have been a pain to load each one by hand. They were meant to be random in the scene anyway, so my approach was to create an image sequence of the pics and then load the sequence into a PSDtextureNode. Then I duplicated the textureNode for each pic i had to load. I then wanted to randomize the offset for each of the texture files.  

The other issue I had was that i was plugging each of these texture nodes into a triple switch which was connected to the color attribute of a surface shader. When there was a few hundred textures to plug in, it became INCREDIBLY tedious.

I'm curious how your approach to this situation would have been. There must be a dynamic way to solve this type of situation.

Thanx again!

-DD 

[joojaa]

I'm curious how your approach to this situation would have been.
There must be a dynamic way to solve this type of situation.

for loop thet creates n texture nodes, connect it to a tripple or quadruple shading swirchand then to the shader node. Then randomize the input slots for the switch in another loop.

Then just use the shading switch as the bundle.

Alternatively load the images to a ramp and use a single switch to select datafrom the ramp.