Difference between revisions of "LlRot2Fwd"

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m (LSL llRot2Fwd moved to LlRot2Fwd: removing prefix)
m (<lsl> tag to <source>)
 
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|func=llRot2Fwd|sort=Rot2Fwd
|func=llRot2Fwd|sort=Rot2Fwd
|return_type=vector|p1_type=rotation|p1_name=q
|return_type=vector|p1_type=rotation|p1_name=q
|func_footnote
|func_desc=Computes the orientation of the {{HoverText|local x-axis|front-direction of prim}} relative to the parent (i.e. the root prim or the world).
|func_desc
|return_text=that is the forward vector defined by {{LSLP|q}}, i.e. a unit vector pointing in the local positive X direction.
|return_text=that is the forward vector defined by '''q'''
|spec=Mathematically equivalent to:
|spec
<source lang="lsl2">ret = llVecNorm(<1., 0., 0.> * q);</source>
If {{LSLP|q}} is known to be a unit quaternion then it can be simplified as:
<source lang="lsl2">ret = <1., 0., 0.> * q;</source>
Keep in mind that object and agent rotations will always be unit quaternions. For example, <1.0, 0.0, 0.0>*llGetRot() is about 25-30% faster than llRot2Fwd(llGetRot()) depending on the VM used. If done often and at extremely fast rates, it can be advantageous to even save <1.0, 0.0, 0.0> to a local/global variable and reuse it.
|caveats
|caveats
|constants
|constants
|examples
|examples=
<source lang="lsl2">
// Move an object 5 metres forwards along its x axis, when touched, no matter how the object is oriented in world.
// Works for a root or child prim
default
{
    touch_start(integer total_number)
    {
        vector v = llRot2Fwd( llGetLocalRot() );
        llSetPos( llGetLocalPos() + v * 5 );
    }
}
</source>
|helpers
|helpers
|also_functions=*{{LSLG|llRot2Left}}
|also_functions=
*{{LSLG|llRot2Up}}
{{LSL DefineRow||[[llRot2Left]]}}
*{{LSLG|llRot2Axis}}
{{LSL DefineRow||[[llRot2Up]]}}
*{{LSLG|llRot2Angle}}
{{LSL DefineRow||[[llRot2Axis]]}}
{{LSL DefineRow||[[llRot2Angle]]}}
|also_tests
|also_tests
|also_events
|also_events
|also_articles
|also_articles
|notes
|notes=Can be useful to identify the orientation of the local {{HoverText|frontal-plane|coronal-plane}} of the prim, since its x-axis is always perpendicular to this local frontal plane.
|permission
|inventory
|negative_index
|cat1=Rotation
|cat1=Rotation
|cat2
|cat2

Latest revision as of 14:35, 22 January 2015

Summary

Function: vector llRot2Fwd( rotation q );

Computes the orientation of the local x-axis relative to the parent (i.e. the root prim or the world).
Returns a vector that is the forward vector defined by q, i.e. a unit vector pointing in the local positive X direction.

• rotation q

Specification

Mathematically equivalent to:

ret = llVecNorm(<1., 0., 0.> * q);

If q is known to be a unit quaternion then it can be simplified as:

ret = <1., 0., 0.> * q;

Keep in mind that object and agent rotations will always be unit quaternions. For example, <1.0, 0.0, 0.0>*llGetRot() is about 25-30% faster than llRot2Fwd(llGetRot()) depending on the VM used. If done often and at extremely fast rates, it can be advantageous to even save <1.0, 0.0, 0.0> to a local/global variable and reuse it.

Examples

// Move an object 5 metres forwards along its x axis, when touched, no matter how the object is oriented in world.
// Works for a root or child prim
default
{
    touch_start(integer total_number)
    {
        vector v = llRot2Fwd( llGetLocalRot() );
        llSetPos( llGetLocalPos() + v * 5 );
    }
}

Notes

Can be useful to identify the orientation of the local frontal-plane of the prim, since its x-axis is always perpendicular to this local frontal plane.

See Also

Functions

•  llRot2Left
•  llRot2Up
•  llRot2Axis
•  llRot2Angle

Deep Notes

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Signature

function vector llRot2Fwd( rotation q );