Difference between revisions of "LlSitTarget"

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**It will appear to be removed if the [[llSetSitText]] is set to a space " " or similar transparent string.
 
**It will appear to be removed if the [[llSetSitText]] is set to a space " " or similar transparent string.
 
*Attachments cannot be sat upon.
 
*Attachments cannot be sat upon.
*'''rot''' affects the position of the sit-target in a non-intuitive way{{Interval/Footnote}}.
+
*'''rot''' affects the position of the sit-target in a buggy way way.
**[[llSetLinkPrimitiveParams]] is an easy work-around.
+
**To correct for the ''rot'' bug, simply subtract <0,0,0.4> from the position when ''rot'' is zero. See example below.
 +
**[[llSetLinkPrimitiveParams]] is a more difficult work-around.
 
**Animations are relative to the Agent Target, but the Agent Target isn't described by the animation.
 
**Animations are relative to the Agent Target, but the Agent Target isn't described by the animation.
 
*[[llSitTarget]] does not update position of an already seated avatar.
 
*[[llSitTarget]] does not update position of an already seated avatar.
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     {
 
     {
 
         llSitTarget(<0.0, 0.0, 1.0>, ZERO_ROTATION); //The vector's components must not all be set to 0 for effect to take place.
 
         llSitTarget(<0.0, 0.0, 1.0>, ZERO_ROTATION); //The vector's components must not all be set to 0 for effect to take place.
 +
    }
 +
}</lsl>
 +
<lsl>default    //example with work-around for llSetTarget rot bug
 +
{          //place in any prim large enough to sit on at any angle
 +
            //click once to choose a place to sit, a second time to sit there
 +
    touch_start(integer num)
 +
    {
 +
        vector pos=llDetectedTouchPos(0);      //use touch to set sit target
 +
        vector lft=llDetectedTouchBinormal(0);  //use normals to rotate avatar to
 +
        vector up=llDetectedTouchNormal(0);    //sit upright
 +
        rotation rot=llAxes2Rot(lft%up,lft,up)/llGetRot();  //rotate avatar to stand there
 +
        vector siz=llGetAgentSize(llDetectedKey(0));
 +
        pos += 0.65*siz.z*up;      //this places MY avatars feet close to the surface
 +
        pos = (pos-llGetPos())/llGetRot();  //llSetTarget expects local co-ordinates
 +
        if (rot!=ZERO_ROTATION) pos -=<0,0,0.4>;  //here is the work around
 +
        llSitTarget(pos,rot);
 +
        llSetClickAction(CLICK_ACTION_SIT);  //switch to sit for second click
 +
    }
 +
    changed(integer change)
 +
    {
 +
        if (llAvatarOnSitTarget()==NULL_KEY)    //if they unsit,
 +
            llSetClickAction(CLICK_ACTION_TOUCH);  //go back to click mode
 
     }
 
     }
 
}</lsl>
 
}</lsl>

Revision as of 19:36, 22 August 2010

Summary

Function: llSitTarget( vector offset, rotation rot );

Set the sit location for the prim. The sit location is relative to the prim's position and rotation.

• vector offset Additional position for the sit target in local prim coordinates.
• rotation rot Additional rotation for the sit target relative to the prim rotation.

If offset == <0.0, 0.0, 0.0> then the sit target is removed.

Specification

llSitTarget sets the position for the Agent Target (Advanced -> Character -> View Agent Target). The position of the target is based on rot and the offset[1].

Caveats

  • Once a sit target is removed llAvatarOnSitTarget will only return NULL_KEY.
  • Removing or deactivating the script that sets the sit target will not remove the prim's sit target.
    • Sit target is a prim property and not dependent on a script for its continued existence.
  • To remove sit target, use the following:

<lsl>llSitTarget(ZERO_VECTOR,ZERO_ROTATION);</lsl>

  • Shift-copying a prim with a sit target, without a script that will set the sit target again, will not keep the sit target on the copy. (The copy is in the original location when shift-copying.)
  • There is no way to remove the Sit option from the pie menu.
    • It will appear to be removed if the llSetSitText is set to a space " " or similar transparent string.
  • Attachments cannot be sat upon.
  • rot affects the position of the sit-target in a buggy way way.
    • To correct for the rot bug, simply subtract <0,0,0.4> from the position when rot is zero. See example below.
    • llSetLinkPrimitiveParams is a more difficult work-around.
    • Animations are relative to the Agent Target, but the Agent Target isn't described by the animation.
  • llSitTarget does not update position of an already seated avatar.
  • offset is limited to 300.0 meters on each axis. The x, y and z components must be in the range [-300, 300.0][2].
    • If they are outside the acceptable range they are rounded to the closest limit.
All Issues ~ Search JIRA for related Bugs

Examples

<lsl>default {

   state_entry()
   {
       llSitTarget(<0.0, 0.0, 1.0>, ZERO_ROTATION); //The vector's components must not all be set to 0 for effect to take place.
   }

}</lsl> <lsl>default //example with work-around for llSetTarget rot bug { //place in any prim large enough to sit on at any angle

           //click once to choose a place to sit, a second time to sit there
   touch_start(integer num)
   {
       vector pos=llDetectedTouchPos(0);       //use touch to set sit target
       vector lft=llDetectedTouchBinormal(0);  //use normals to rotate avatar to
       vector up=llDetectedTouchNormal(0);     //sit upright
       rotation rot=llAxes2Rot(lft%up,lft,up)/llGetRot();  //rotate avatar to stand there
       vector siz=llGetAgentSize(llDetectedKey(0));
       pos += 0.65*siz.z*up;       //this places MY avatars feet close to the surface
       pos = (pos-llGetPos())/llGetRot();  //llSetTarget expects local co-ordinates
       if (rot!=ZERO_ROTATION) pos -=<0,0,0.4>;  //here is the work around
       llSitTarget(pos,rot);
       llSetClickAction(CLICK_ACTION_SIT);   //switch to sit for second click
   }
   changed(integer change)
   {
       if (llAvatarOnSitTarget()==NULL_KEY)    //if they unsit,
           llSetClickAction(CLICK_ACTION_TOUCH);   //go back to click mode
   }
}</lsl>

Useful Snippets

UpdateSitTarget

<lsl>//Sets / Updates the sit target moving the avatar on it if necessary. UpdateSitTarget(vector pos, rotation rot) {//Using this while the object is moving may give unpredictable results.

   llSitTarget(pos, rot);//Set the sit target
   key user = llAvatarOnSitTarget();
   if(user)//true if there is a user seated on the sittarget, if so update their position
   {
       vector size = llGetAgentSize(user);
       if(size)//This tests to make sure the user really exists.
       {
           //We need to make the position and rotation local to the current prim
           rotation localrot = ZERO_ROTATION;
           vector localpos = ZERO_VECTOR;
           if(llGetLinkNumber() > 1)//only need the local rot if it's not the root.
           {
               localrot = llGetLocalRot();
               localpos = llGetLocalPos();
           }
           pos.z += 0.4;
           integer linkNum = llGetNumberOfPrims();
           do{
               if(user == llGetLinkKey( linkNum ))//just checking to make sure the index is valid.
               {
                   llSetLinkPrimitiveParams(linkNum,
                                           [PRIM_POSITION, ((pos - (llRot2Up(rot) * size.z * 0.02638)) * localrot) + localpos,
                                            PRIM_ROTATION, rot * localrot / llGetRootRotation()]);
                   jump end;//cheaper but a tad slower then return
               }
           }while( --linkNum );
       }
       else
       {//It is rare that the sit target will bork but it does happen, this can help to fix it.
           llUnSit(user);
       }
   }
   @end;

}//Written by Strife Onizuka, size adjustment provided by Escort DeFarge</lsl>

GetSitTarget

<lsl>list GetSitTarget(integer prim, key av) {//WARNING: llGetObjectDetails can introduce an error that goes as far as the 5th decimal place!

//This is highly unlikely to be ever noticed unless compounded over time.
//Do not use while moving (like in a moving vehicle)!!!
   vector tp = llGetAgentSize(av);
   if(tp)
   {
       if(prim == LINK_THIS)//llGetLinkKey doesn't like LINK_THIS
           prim = llGetLinkNumber();
       
       list details = [OBJECT_POS, OBJECT_ROT];
       rotation f = llList2Rot(details = (llGetObjectDetails(llGetLinkKey(prim), details) + llGetObjectDetails(av, details)), 1);
       rotation r = llList2Rot(details, 3) / f;
       return [((llList2Vector(details, 2) - llList2Vector(details, 0)) / f) + (llRot2Up(r) * tp.z * 0.02638) - <0.0, 0.0, 0.4>, r];
   }
   return [];

}//Written by Strife Onizuka</lsl>

See Also

Events

•  changed

Functions

•  llSetSitText
•  llAvatarOnSitTarget
•  llUnSit

Deep Notes

Search JIRA for related Issues

Footnotes

  1. ^ It is widely considered that the rot should not affect the position, unfortunately the sit target code is a lava-flow. ~ SVC-2277
  2. ^ The ranges in this article are written in Interval Notation.

Signature

function void llSitTarget( vector offset, rotation rot );