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  • Parenting and expressions

    Posted by Paul Roper on December 16, 2010 at 6:19 pm

    Hmmm…I must have a bit of brain fade – this is something I’ve done before but I just can’t remember how. Hopefully someone can please remind me!

    I have a comp with a wizard holding a wand. He sweeps the wand around and magic particles (using CC Particle World) emit from the end of his wand. Not very original I know, but hey, that’s what the punters want. Anyway, if I do an expression to link the producer pos.x and pos.y to a null parented to the end of the wand, obviously nothing happens, because the null’s pos.x and pos.y do not change – its movement comes from its parenting. The arm only has rotation – no position change. Kinda like this:

    The green cross represents the null, parented to the red arm which pivots around the black pivot.

    CC Particle world’s particles do not inherit movement from the layer it’s on, only from movement of the source point (producer).

    Any suggestions? Thanks in advance!

    Michael Szalapski replied 15 years, 5 months ago 2 Members · 3 Replies
  • 3 Replies
  • Michael Szalapski

    December 16, 2010 at 7:37 pm

    To reference the position of a child of a parent:
    L=thisComp.layer("Child layer name");
    L.toWorld(L.anchorPoint);

    – The Great Szalam
    (The ‘Great’ stands for ‘Not So Great, in fact, Extremely Humble’)

    No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

  • Paul Roper

    December 16, 2010 at 7:56 pm

    Fantastic. Does the job perfectly – you are a star!

    Thank you!

  • Michael Szalapski

    December 16, 2010 at 9:10 pm

    No problem, glad to know it’s working for you.

    – The Great Szalam
    (The ‘Great’ stands for ‘Not So Great, in fact, Extremely Humble’)

    No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

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