directional contraint and 'cycle created': workaround

[ChristianFischer]

create a third null which has a pose constraint to the first one.
now direction constraint the second one to the third one ...

cheers chris

[moonsafari]

chris...i just tried that and ended up with the same cycle error. this is what i did.

null 3 is pose contrained to null 1
null 1 is direction constrained to null 2
null 2 is direction constrained to null 3

thanks for the help

[ChristianFischer]

uh .. i should have tried it before posting it .. sorry.

but although there pops up a cycle dependency warning the constraints work fine.
i tried it with 2 cones and no matter which cone you move it always looks into the direction of the other cone (see file (http://people.freenet.de/3d-stuff/muell/direction_cns.zip) )

regards chris

[ThE_JacO]

dependancy cycles are a warning, but it doesn't mean that something is necessarily going to go wrong, the warning is there to let you know there's something happening IF something goes tits up.

as for the setups for reciprocous facing I usually like a different setup.

get 2 cones and a cube.
constrain the cube with a constrain 2 points to the 2 cones.
constrain direction each cone to the cube.

now you get your setup (and a nice cycle dependancy warning you can ignore :) )

if the refresh becomes wacky (like you move the cube and the cones point to the where the cube should be but really is not) just set a position keyframe on the cube, that will not affect its position since the 2points constrain affects the global positioning but it will take care of refreshing the scene constantly and correctly.

edit: almost forgot.
for a more solid/reliable refresh you could want, rather then a nice 2points cns, use 2 balanced cns positions.
this will completely prevent manipulation of the translation on the object but you will have one more cns to monitor if you revise the scene.

just remember to always use annotation properties when your setups become complex, since you can't rename constraints and it's fairly hard, 6 months after you setup something, to remember which one was doing what.

[moonsafari]

thanks for the help everyone. it's been much appreciated.

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