Difference between revisions of "LlVecDist"

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(Added some stuff to notes. Perhaps someone (Strife :D?) could make sure they're okay to add?)
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** [[llVecMag]]( vec_a - vec_b )
 
** [[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) )
 
** [[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;
 
|cat1=Math/3D
 
|cat1=Math/3D
 
|cat2=Vector
 
|cat2=Vector

Revision as of 18:19, 20 July 2012

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

<lsl> 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) );
   }

} </lsl>

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

Search JIRA for related Issues

Signature

function float llVecDist( vector vec_a, vector vec_b );