Help with school project

Programming Questions

joeynoh

in Programming Questions • 3 years ago

Me and my groupmates are supposed to make a simple game for our processing class. They asked us to make a game where one can move blocks with the used of a webcam (so when i move my hand over the block, it moves along with my hand). Also, the player needs to be able to build simple structures with the blocks (pretty much just putting one block on the other), so i'm guessing a physics library is needed?

With our limited knowledge and our school refusing to give us any useful information, i find myself here asking you guys kindly for help. It's due on thursday and so far i havent even come close.

When we asked our teacher for help he gave us the source code for a webcam pong game. I thought i could use the same method to move the paddles to move the blocks in my game, but unfortunately i was unable to do this.

So please, any help with much appreciated.

Thanks in advance!,

Joey

Replies(3)

PhiLho

Re: Help with school project

3 years ago

I can't help with the webcam part (seems hard for somebody without computer vision knowledge like me, in such short delay).
But I think you can drop the physics idea: basically it is a good idea, but again you have little time to learn to use it.
I mean, the blocks can be always parallel to the side (no tilting) and then collision detection of rectangles is quite trivial.
Suggestion: perhaps solve your assignment with moving the blocks with the mouse (the easy part), then if you have still some time, look how to use the webcam as input.

Jack Kern

Re: Help with school project

3 years ago

I think you could accomplish what you want using the BoxWrap2D library for physics and one of the blob dection libraries, like the OpenCV library.

The trick will be determining where your finger tips are, and you may need a special lighting rig to do it well. The way most DIY touch screens do it is to get a thick sheet of acrylic and line the outside with infrared LED's. With the LED's on, when you touch the acrylic it causes the inferred light that's bouncing internally due to total internal reflection to be bounced out away from you, right were you touched. So all you need to do is put the web cam over the screen facing the acrylic sheet. Webcams are very sensitive to infrared light and so some have an IR filter in them you may need to remove, but even if you don't you can usually pick up touches as bright lights on the webcam.

Finally you just use blob detection to pick up all the locations of touch, and then you have to figure out the correct transformations to get those points into screen space, because the will be distorted from what you actually want.

Make sense? I'm happy to clarify anything I didn't explain well enough. And, this isn't the only way to do it, just one that I know has been done and works. It might be possible to use a low power laser and a spinning mirror to get a similar effect without any surface in between the display and the user.

BoxWrap2D Library: http://jbox2d.nfshost.com/processing/

OpenCV Wrapper Library: http://ubaa.net/shared/processing/opencv/opencv_blobs.html

local_guru

Re: Help with school project

3 years ago

Hi,

One way you could achive the movement detection is comparing the last image of the camera to the current one and

see if it has changed (more than given treshold to filter out noise). This way you can detect any movement (but it needs not

be a hand of the player - any movement will do). This is (veeeery roughly) the way the eye-toy games work.

Another way is trying to match the color of the finger. look here

http://www.local-guru.net/blog/2008/10/10/touchless-multitouch-in-processing for an example

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