GPS - Global Position System

Autodesk Smoke Tips & Tricks - GPS

I'm back !! See, i told you "i'll be back!!" even though i forgot to wear my sun glasses. This technique is simple yet very powerful, it will detect the positionXY of an object. It's a bit advance than the GPS because mine also detect rotation.
Refer to the diagram below, the leftmost node is "A" still image attach to axis1. Text1 and Text2 node are label text "Position X" and "Rotation Z". You can add Text3 "Position Y" yourself here.Ready a 10 frames clip (from 0 to 9), enter as media 6 times. The 1st 3 is for position, last 3 is for rotation. Add 3 more if you have positionY.
For the 1st left number clip (the 10 frames) , in media slip & matte slip, enter expression :
((floor(abs(axis1.position.x/100))%10)+1)- frame

For the 2nd left number clip, enter expression :
((floor(abs(axis1.position.x/10))%10)+1)- frame

And for 3rd, enter expression :
((floor(abs(axis1.position.x/1))%10)+1)- frame

Now for the next 3 number clips.

For the 4th left number clip, enter expression :
((floor(abs(axis1.rotation.z/100))%10)+1)- frame

For the 5th number clip, enter expression :

((floor(abs(axis1.rotation.z/10))%10)+1)- frame

And for 6th, enter expression :
((floor(abs(axis1.rotation.z/1))%10)+1)- frame
Now, move and rotate your axis1 A image. The GPS will start to work.

For the negative and positive sign, you can add a 2 frames clip (+ and -), then in the media slip add expression :

frametoslip(if(axis1.position.x>=0, 1, 2))

As i mentioned earlier, this is very powerful technique, it can detect any parameter for an object (position, rotation, scaling, transparency, rgb color, crop .....). Plus, you can use it as number counter as well, just throw the A image away and use the axis positionX to control the counter.