How to move-rotate a child prim relative to another child prim?

[Poltergeist Azarov]

Like on rezboxes, how to move-rotate child prims relative to another child prim? Been working on this since a while but cant solve it, any ideas?

[Dora Gustafson]

All you need is in here
The formulas are general and can be used on global and or local rotations
Looks like you will need to find and apply some local relation between child prims

:smileysurprised::smileyvery-happy:

[Poltergeist Azarov]

Thanks, I have seen these but didnt really understand since there were no examples :\ Thanks though.

[Poltergeist Azarov]

        rotation PRIM2ROT=llList2Rot(llGetLinkPrimitiveParams(2,[PRIM_ROT_LOCAL]),0);        vector   PRIM2POS=llList2Vector(llGetLinkPrimitiveParams(2,[PRIM_POS_LOCAL]),0);                 rotation PRIM3ROT=llList2Rot(llGetLinkPrimitiveParams(3,[PRIM_ROT_LOCAL]),0);         vector   PRIM3POS=llList2Vector(llGetLinkPrimitiveParams(3,[PRIM_POS_LOCAL]),0);                         rotation relativeRot = PRIM3ROT / PRIM2ROT;        vector   relativePos = (PRIM3POS - PRIM2POS) / PRIM2ROT;               llSetLinkPrimitiveParamsFast(3,[PRIM_POS_LOCAL,relativePos,                                            PRIM_ROT_LOCAL,relativeRot]);

 For example, this does not do the expected behaviour. 

[Dora Gustafson]

You left out the calculation for prim 3

rotation PRIM2ROT=llList2Rot(llGetLinkPrimitiveParams(2,[PRIM_ROT_LOCAL]),0);vector   PRIM2POS=llList2Vector(llGetLinkPrimitiveParams(2,[PRIM_POS_LOCAL]),0);rotation PRIM3ROT=llList2Rot(llGetLinkPrimitiveParams(3,[PRIM_ROT_LOCAL]),0);vector   PRIM3POS=llList2Vector(llGetLinkPrimitiveParams(3,[PRIM_POS_LOCAL]),0);rotation relativeRot = PRIM3ROT / PRIM2ROT;vector   relativePos = (PRIM3POS - PRIM2POS) / PRIM2ROT;PRIM3ROT = relativeRot * PRIM2ROT;PRIM3POS = PRIM2POS + relativePos * PRIM2ROT;llSetLinkPrimitiveParamsFast(3,[PRIM_POS_LOCAL,PRIM3POS, PRIM_ROT_LOCAL,PRIM3ROT]);

The first 6 lines should be computed one time and the first 2 and the last 3 should be computed each time Prim 2 change position or rotation

This will give Prim 3 the same relation to Prim 2 no matter how prim 2 is rotated and moved

I hope this is helpful

:smileysurprised::smileyvery-happy:

[Poltergeist Azarov]

This works great Thanks alot. I hope I can find a way to make it simpler more than below code. Since it costs alot this way just for a simple operation.

rotation PRIM2ROT;vector   PRIM2POS;rotation PRIM3ROT;vector   PRIM3POS;rotation PRIM4ROT;vector   PRIM4POS;rotation PRIM3RELROT;vector   PRIM3RELPOS;rotation PRIM4RELROT;vector   PRIM4RELPOS;list Relatives;default{    state_entry()    {        PRIM2ROT=llList2Rot(llGetLinkPrimitiveParams(2,[PRIM_ROT_LOCAL]),0);         PRIM2POS=llList2Vector(llGetLinkPrimitiveParams(2,[PRIM_POS_LOCAL]),0);                PRIM3ROT=llList2Rot(llGetLinkPrimitiveParams(3,[PRIM_ROT_LOCAL]),0);        PRIM3POS=llList2Vector(llGetLinkPrimitiveParams(3,[PRIM_POS_LOCAL]),0);                PRIM4ROT=llList2Rot(llGetLinkPrimitiveParams(4,[PRIM_ROT_LOCAL]),0);        PRIM4POS=llList2Vector(llGetLinkPrimitiveParams(4,[PRIM_POS_LOCAL]),0);                PRIM3RELROT=PRIM3ROT / PRIM2ROT; PRIM3RELPOS=(PRIM3POS - PRIM2POS) / PRIM2ROT;        PRIM4RELROT=PRIM4ROT / PRIM2ROT; PRIM4RELPOS=(PRIM4POS - PRIM2POS) / PRIM2ROT;                        }    touch_start(integer total_number) {               PRIM2ROT=llList2Rot   (llGetLinkPrimitiveParams(2,[PRIM_ROT_LOCAL]),0);        PRIM2POS=llList2Vector(llGetLinkPrimitiveParams(2,[PRIM_POS_LOCAL]),0);                PRIM3ROT = PRIM3RELROT * PRIM2ROT;        PRIM3POS = PRIM2POS + PRIM3RELPOS * PRIM2ROT;                PRIM4ROT = PRIM4RELROT * PRIM2ROT;        PRIM4POS = PRIM2POS + PRIM4RELPOS * PRIM2ROT;                llSetLinkPrimitiveParamsFast(3,[PRIM_POS_LOCAL,PRIM3POS, PRIM_ROT_LOCAL,PRIM3ROT,                    PRIM_LINK_TARGET,4, PRIM_POS_LOCAL,PRIM4POS, PRIM_ROT_LOCAL,PRIM4ROT]);    }}

 

[Dora Gustafson]

Pretty code you wrote:)

It certainly looks a lot, but you also gain a lot
The code is universal and will work in any case (within LSL limits)
It might be simplified for special cases, say zero rotations
When the relative rotation and position are constants they can be calculated in another script and written as constants
Code may be merged into fewer lines but I don't think that will make it any easier

:smileysurprised::smileyvery-happy: