How to get the Normal Vector in the center of three coordinates

This is probably the worst tutorial title of the universe, but i didn’t get any other idea to sum it up more catchy. It’s the last follow up on the popup book tutorials and an interesting technique in general:

let’s say you have three points, objects, whatever and want to not only get the orthogonal vector (normal vector) of the invisible plane between these coordinates, but also the position in the center of these three coordinates. Here’s how you can do it:


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  1. Remo

    The 2nd mixer should actually do 33% (or 66%), not 50%, because you mix ONE vector with the mix of TWO vectors, so it has to be weight 1:2 (or 33%:66%).



  2. Hi Robert !

    Many thanks again for all your cool stuff done in Xpresso, we all learnt a lot from you !
    I just was wondering… Have you got any idea about the date you’ll be able to launch your “Pop-up preset” you talked about at the end of the video ?
    I ask that cause i really need it for a really urgent project… any chance it could arrive soon ?

    Thanks again and keep up the good job !

    • i’m still working on it, but had to put it aside due to work.
      i’ll get back to it soon, but i don’t think it will be done this month.

      • Hi Robert !

        Thanks for your response…
        Okay, it doesn’t matter ; i’ll try to combine all i have learnt from your lessons and tutorials with xpresso and rigs. In fact, this project is a really good exercice for me as it put in practice the “theorical” part of your tutorials. I will probably send you a link to view my final project when it will be finished (if you are interested in of course)

        Anyway, sorry for my bad english (i’m french and yours is really better than mine), and keep up the good stuff !

        • @Fremox: If/when you finish the project, I’d love to see the result & how you went about completing it.

          • Hi guys !
            I just finished the project i told you here…
            Now i can say clearly what it is… I became a father for the first time a few days ago and, as i am a freelancer graphic designer who loooooves using Cinema 4D, After Effect and Flash, i wanted to create something very special for my little baby daughter…
            So i created a full flash website which tells the story of the parents (my wife and my self since the first day we met until the birth of our daughter) in the form of an interactive pop-up book in 3D !
            So that was why i need the help of Robert, and, thanks to his great tutorial, i managed to build the central parts of each page of the pop-up book, and the result has been loved by all my friends and familly.. I hope you’ll like it too ;)

            Here’s the link to the full flash website :

            and the video screencast i posted on Vimeo to see it in action :

          • That is wonderful, I love it! Also congrats for becoming a dad!

  3. Hi Robert!
    I tried to recreate this setup. It kind of worked. But whenever I add the Global Matrix, the position of the cone stays at the world center. When I delete the Global Matrix port the position is again calculated by the position of the 3 Nulls.
    I watched your video several times and there is really no difference between your setup and mine. Any ideas what I’m doing wrong?

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