LlVecDist - Second Life Wiki

LlVecDist

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Summary

Function: float llVecDist( vector vec_a, vector vec_b );

Returns a float that is the undirected nonnegative distance between vec_a and vec_b.

• vector vec_a Any valid vector
• vector vec_b Any valid vector

Examples

default {
    state_entry()
    {
        vector input_1 = <1.0,2.0,3.0>;
        vector input_2 = <3.0,2.0,1.0>;
        llOwnerSay("The distance between " + (string) input_1 +
            " and " + (string) input_2 + " is: "+(string)llVecDist(input_1, input_2) );
    }
}
//To reset script on touch if the object has been rotated since the last script reset
float gTolerance = 0.05;  //This corresponds to about a 3 degree rotation
default
{
	state_entry()
	{
		llSetObjectDesc((string)llRot2Euler(llGetRot()));
	}
 
	touch_start(integer total_number)
	{
		if (llVecDist(llRot2Euler(llGetRot()), (vector)llGetObjectDesc()) > gTolerance)
		{
			llSay(0,"This object has rotated. Automatic reset engaged.");
			llResetScript();
		}
	}
}

Video Tutorial

Notes

  • Mathematically equivalent to:
    • llVecMag( vec_a - vec_b )
    • llSqrt( (vec_b.x - vec_a.x) * (vec_b.x - vec_a.x) + (vec_b.y - vec_a.y) * (vec_b.y - vec_a.y) + (vec_b.z - vec_a.z) * (vec_b.z - vec_a.z) )
  • Knowing this, there are ways to circumvent llVecDist for more efficient code.
    • For example, vector v3 = (v1-v2); v3*v3 < (f*f); is over twice as fast as llVecDist(v1,v2) < f;

See Also

Functions

•  llVecMag
•  llVecNorm

Deep Notes

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