//Daniele Tosti - studiolito@3dtreat.com
//Tested with Maya 3.01
//Change at will and let me know if you have any suggestions.
//
//
//Run this to set the radiusPP of your particles depending on the distance from the camera.
//
//1-Make sure you replace correctly the name of the particle in your scene in the $partCloudName string.
//2-You can fine tune the radius limits through the $NewRadiusPP float.
//Just remember that LINSTEP returns a floating point value between zero and one representing 
//what percentage of the distance between the first and second arguments is represented by the third argument. 
//The second argument is farthest distance between the particles and your camera. 



proc RPPCD ()
{
	string $partCloudName = "particle1";
	int $partSize = `particle -count -q $partCloudName`;
	print ($partSize+"  ");
	int $partID;

	for ($partID = 0; $partID < $partSize; $partID++)
	{
		print ($partID+" ");
		float $partPos[3] = `particle -attribute position -id $partID -q $partCloudName`;

		string $distNNode = `createNode distanceBetween`;
		setAttr distanceBetween1.point1 ($partPos[0]) ($partPos[1]) ($partPos[2]);
		connectAttr -f persp.translate distanceBetween1.point2;

		float $DistFromCamera = `getAttr distanceBetween1.distance`;

		float $NewRadiusPP = 5*(1.75+linstep (0,130,$DistFromCamera));
			
		select -cl;
		select ($partCloudName+".pt["+$partID+"]");
		setParticleAttr -at radiusPP -fv $NewRadiusPP; 
		
		print ("distance " + $DistFromCamera);
		print (" linstep " + $NewRadiusPP + "\n ");
		delete $distNNode;
	}
 }