I’m using the “contour” to do tracking for a multitouch interface project (using vvvv and processing). I have a “displacement” between the coordinate returned by “contour” and what I’m drawing with processing/projecting on the interface.
To correct the displacement I’m thinking to use a parabola equation “A*sqr(X)”. Feeding two “expr” objects with the x and y returned by “contour”.
The problem is that I need to have at least two blobs (detected by “contour”) for getting a value out of “expr”. With only one “expr” returns O
I must be missing something really obvious …
ps: i’m new to vvvv …:-(… but working hard to change that
hi guys as ususal ,m not sure if i understood you but if you want that a position from a blob remains you can use count + s+h and maybe getslice for the blobs you want , change the mouse for contour ; D
Thanks Oschatz…you put me on the good direction when you said: “note that Expr is sometimes slow - the Power can be used to do squares. even faster for your formula might be a * (Value) with three inputs (use the inspector)” … I don’t understand why, but if I do the same equation by “hand” it works… instead of using “expr” and use a combination of “power”, “*” and “+”.