View Full Version : Raw IR point continuity

02-28-2011, 02:29 AM

I'm working with raw IR using between 0-4 points. To give some context for my question, imagine the following scenario:

* I put two points up (which appear as 1 & 2), then move them to the left (1) and right (2) extremes of the camera detection area so that they both move out of range.

* On the right side, I re-enter the camera detection area with an IR point as nearly as possible to where (2) left off as I exited range.

About half the time the right hand point (2) will pick right up and continue where it left off. Other times the left point (1) will slide all the way over in an interpolating fashion to take over where (2) was.

This is all completely contained within OSCulator as viewed in the graphs, before I route the data to another application. I wrote my own software for maintaining continuity between points, which works well using points on Apple's multitouch pads as input, for instance.

So my question is whether or not this interpolation is a feature you've added to try to maintain continuity between points, or if this is what comes off of the Wii remote as is. If it is your feature, are there any further controls for it that I should know about? I guess the bottom line is that it doesn't matter to me what order the points show up in, but I don't want any transitional sliding going on when point IDs are reassigned.

I hope this paints enough of a picture for you to provide me with an answer. I'm quite a happy customer with OSCulator in general - excellent work!


02-28-2011, 08:08 PM
Hi William,

The Raw IR data is almost what the Wiimote provides.
The only processing made is the normalization of the X and Y axes.
To the best of my knowledge, the Wiimote tries to maintain some sort of continuity, but it does not work all the time. In fact, there are many ways of interpreting the data, and if you want full control over it, it's up to you to decide how you deal with the available dots. For example, when calculating the IR X/Y virtual pointer, the algorithm is locating the leftmost and rightmost dots (which is depending on the roll orientation), and calculates the barycentric center.