Difference between revisions of "LlRot2Fwd"
Omei Qunhua (talk | contribs) (Provide an example) |
Omei Qunhua (talk | contribs) m (Correct initial statement re: child prims, and adjust example to for both root and child prims) |
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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_desc=Computes the orientation of the {{HoverText|local x-axis|front-direction of prim}} relative to | |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). | ||
|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 {{LSLP|q}}, i.e. a unit vector pointing in the local positive X direction. | ||
|func_footnote=Can be useful to identify the orientation of the local {{HoverText|frontal-plane|coronal-plane}} of the prim, since it's x-axis is always perpendicular to this local frontal plane. | |func_footnote=Can be useful to identify the orientation of the local {{HoverText|frontal-plane|coronal-plane}} of the prim, since it's x-axis is always perpendicular to this local frontal plane. | ||
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touch_start(integer total_number) | touch_start(integer total_number) | ||
{ | { | ||
vector v = llRot2Fwd( | vector v = llRot2Fwd( llGetLocalRot() ); | ||
llSetPos( | llSetPos( llGetLocalPos() + v * 5 ); | ||
} | } | ||
} | } | ||
Revision as of 10:38, 6 December 2013
| LSL Portal | Functions | Events | Types | Operators | Constants | Flow Control | Script Library | Categorized Library | Tutorials |
Summary
Function: vector llRot2Fwd( rotation q );| 18 | Function ID |
| 0.0 | Forced Delay |
| 10.0 | Energy |
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 |
Can be useful to identify the orientation of the local frontal-plane of the prim, since it's x-axis is always perpendicular to this local frontal plane.
Specification
Mathematically equivalent to: <lsl>ret = llVecNorm(<1., 0., 0.> * q);</lsl> If q is known to be a unit quaternion then it can be simplified as: <lsl>ret = <1., 0., 0.> * q;</lsl> 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
Examples
<lsl> // Move an object 5 metres forwards along its x axis, when touched, no matter how the object is oriented in world. default {
touch_start(integer total_number)
{
vector v = llRot2Fwd( llGetLocalRot() );
llSetPos( llGetLocalPos() + v * 5 );
}
}
</lsl>See Also
Functions
| • | llRot2Left | |||
| • | llRot2Up | |||
| • | llRot2Axis | |||
| • | llRot2Angle |