Frans-Jan Wind

I'm working on a patch which uses z-axis information (depth) to calculate the size of an object.

For instance an object has a width of 300 units (pixels) at 3000 units (mm) distance. The same object has a width of 400 units as 2000 units distance. With these statics I should be able to calculate the size at 2500 units distance (using a formula). I know for many of you this is basic math, but I just can't figure it out without using too many [scale] objects

And yes, I posted this in MaxMSP on purpose, since this is done without jitter.

Hi,
I'm working on a patch which uses z-axis information (depth) to calculate the size of an object.

calculate-size-on-different-distances

It may help you to think of your widths as y's and distances as x's, then use

given a pair of points, you should find it straightforward to solve for the slope and intercept.

This sure did help me. But sadly it wasn't straightforward but a case of trial and error for me. The following patch after your example gave me an answer (Y=-0.1X+600).

This patch should guide you on how to do this programatically (bit scruffy but hey)

What you have here essentially is the slope being the change in y/change in x, or (y2-y1)/(x2-x1)

then given that (we'll call that value 'a')

Calculate size on different distances