Wiimote Project
Wiimote Projects => Wiimote Interactive Whiteboard => Topic started by: eyucel on January 16, 2009, 07:55:48 AM

Hi,
I made some experiments to figure out the wiimote camera angles. They are vertical 30 degrees, horizontal 40 degrees.
The camera sees a 112*82 rectangular area from a 150 cm away and the wiimote is horizontal to the ground.
a 172*132 rectangular area from a 240 cm away.
I hope this helps.
Take care

In order to decide how far you have to put the wiimote from the screen, one needs the following formula.
x=((the screen sizehorizontal)/2)/tan(radians(20))
x=((the screen sizevertical)/2)/tan(radians(15))
An example;
The screen size horizontal is 130 cm. The result of tan(radians(20))=0.36397
x= (130/2)/0.36397=178.50 cm.
But, if the screen size vertical is also 130 cm, then x=((the screen sizevertical)/2)/tan(radians(15))
tan(radians(15))=0.267949
x= (130/2)/0.267949=242.50 cm.
These are approximate distances, but very close to the true numbers.

Oh nice, I applaud your numbers.
Though you've got a few typos in you post. In your examples you multiply the 0.36397 instead of correctly dividing.

eyucel
Great work!
Supports sts70nl previous work http://www.wiimoteproject.com/wiimotewhiteboard/firsttrialidealdistancewiimoteandltandgtsizescreen/msg4441/#msg4441 (http://www.wiimoteproject.com/wiimotewhiteboard/firsttrialidealdistancewiimoteandltandgtsizescreen/msg4441/#msg4441) who produced similar figures.
Its good to know that if you want to use a Wide Screen just lay the Wiimote on its side!
benpaddlejones :)

mine is ceiling mounted almost parallel with the LCD projection

What I'm trying to work out  is what is the maximum distance you can put the wiimote before it's out of focus!
I use a fairly large screen with rear projection and have been having some problems (still working out what they are)
The screen  if the full area is used  is about 8ft W x 6ft H
I understand that the basic rule is twice the height should be the distance away  so 12 feet in my case does the wiimote also need to be at a particular height and angle in relation to the screen as per the diagram above in this thread?
As we can't see an image of what the wiimote is "seeing" it does make it difficult to get things spot on!