投射螢幕上會走動的糖果是如何運作的?

簡單：
通常是利用肉眼見不到的紅外線，透過接收和計算由你身體反射的訊號，準確知道你踩踏螢幕的位置，再以電腦程式使糖果作出相應走動，並不算 Motion Sensor，比其複雜，因為要計算座標，不是單單移動。 多人同時遮住那些糖，D 糖自然會走到沒有反射訊號的螢幕位置，直到全個螢幕也給踏著。

詳細：
原理和市面的激光投射虛擬鍵盤一樣。
A.
Step 1: Template creation (Projection Module)
A template of the desired interface is projected onto the adjacent interface surface.
Step 2: Reference plane illumination (Micro-illumination ModuleTM)
An infra-red plane of light is generated just above, and parallel to, the interface surface. This light is invisible to the user and hovers a few millimeters above the surface.
Step 3: Map reflection coordinates (Sensor Module)
Reflected light from user interactions with the interface surface is passed through an infra-red filter and imaged on to a CMOS image sensor in the sensor module.
Custom hardware embedded in the sensor chip (the Virtual Interface Processing CoreTM) then makes a real-time determination of the location of the reflected light.

http://www.virtual-laser-keyboard.com/demo.asp

B.
1) Laser projects visible virtual keyboard onto level surface.
2) Invisible infared beam is projected above virtual keyboard.
3) Finger makes keystroke on virtual keyboard. This breaks infared beam and infared light is reflected back to projecter.
4) Reflected infared beam passes through infared filter to camera.
5) Camera photographs angle of incoming infared light.
6) Sensor chip determines where infared beam was broken and translates it into co-ordinates.
7) Characters are created on screen, using co-ordinates sent wirelessly

http://en.wikipedia.org/wiki/Virtual_keyboard

2007-03-03 09:39:42 補充：
由於程式乃參考參與者的座標位置，亦相等於將該些位置排除在糖果走動路線，正常是永遠踩不到的，就如動物追逐自己的尾巴那般，除非程式中刻意加入特殊指令，例如在一定次數追逐後，便放棄逃跑，好讓參與者高興一番。

2007-03-03 10:24:51 補充：
此等技術不會使出在防盜或環保的自動裝置上，因為它們不必計算座標值，只是直接探測監察範圍有紅外線放出的大型物體的運動，即人類，人體本身已經能夠放出紅外線，不用向目標發出紅外線，亦不用多加計算該人所在點。

2007-03-05 10:35:38 補充：
高精度的紅外線裝置的確是檢測反射訊號，A 的 Step 3: Map reflection coordinates 『 Reflected light from user interactions with the interface surface is passed through an infra-red filter ‧‧‧』已經好清楚。

2007-03-05 10:41:57 補充：
防盜或環保的自動裝置上使用的是 PIR，Pyroelectric Infrared Detectors，的確直接是檢測動物身上的紅外線，而且可以分辨人和寵物，防止錯誤觸發。『 Pet-Tolerant for animals up to 38 kg (85 lb).‧‧‧』 http://homesecuritystore.com/ezStore123/DTProductZoom.asp?productID=1573

2007-03-05 10:44:19 補充：
How Infrared motion detector components work『 ‧‧‧which is most sensitive to human body radiation.』http://www.glolab.com/pirparts/infrared.html

2007-03-05 10:45:44 補充：
Pyroelectric Infrared Detectors :http://www.fuji-piezo.com/prodpyro.htm

2007-03-05 10:48:45 補充：
PIR 使用在防盜或環保的自動裝置上的產品：http://www.eurobatteries.com/sitepages/pir-sensors.asp

2007-03-05 10:50:28 補充：
Pyroelectricity - http://en.wikipedia.org/wiki/Pyroelectric

2007-03-05 11:15:09 補充：
利用影像拍攝，如早年使用在遊戲那種，一開始已經考慮過，但因考慮到是投射在地面，拍攝角度及分辨足跡較困難，早已排除。當然，這技術是可以的，不過效果不會理想。例如：踩在地面的腳和準備踩，離地面一呎的腳，拍攝方法是不能分辨，但紅外線虛擬觸控可以簡單做到。

2007-03-05 11:20:56 補充：
由於引用激光投射虛擬鍵盤作例，其利用激光投射可見的虛擬鍵盤技術的這部份，並不適用於這問題。

2007-03-05 11:54:56 補充：
紅外線虛擬觸控投射技術：http://delivery.acm.org/10.1145/1190000/1186176/p20-simpson.pdf?key1=1186176&key2=3726603711&coll=&dl=GUIDE&CFID=15151515&CFTOKEN=6184618

2007-03-05 12:09:59 補充：
PIR switch 裝置：『 ‧‧‧detects movement of a warm body moving within its detection zone‧‧‧』 warm body !!!!! http://www.robertpearson.co.uk/pir.asp

2007-03-05 16:17:27 補充：
另外，別以為利用影像拍攝方式會較簡單，相反，實際比紅外線虛擬技術更複雜，彼此都要做座標值計算，影像拍攝方式還要額外加入去除背景及手腳辨別功能，並非想像中容易。

2007-03-06 10:37:56 補充：
一定係錯？反射訊號做法會引起大量錯誤數據？事實上，無論動物、商業或軍事產品，也是利用反射回來的訊號！ULTRASONIC DISTANCE DETECTION FOR VEHICLES 『 ‧‧‧detecting sonic echoes from close objects‧‧‧』http://www.wikipatents.com/3842397.html

嘩, 上面的人講到咁西利, 又motion detection, 又激光.... 勁.

佢個projector, 有個相機既. 佢將佢 project 出黎既 image, 再影番入電腦入面.
咁個電腦將而家個相機影度既影像, 同佢自已project 出去既比較吓, 咪知有咩唔同左, 就係有外物囉.... 之後就係個program 再點玩都得.

基本上原理好簡單；通常係將該部份範圍接上動作感應器（好簡單的裝置，可以是紅外線感熱或用微波／超聲波探測），只要感應到該區域有任何動作便會觸發電腦自動撤換至另一組的影像．這種技術也會應用在防盜（觸發的是警報）或環保裝置（觸發的是電掣開關）上．
以下是Wikipedia的簡介：
Motion Detection
Motion detection is the sensing (usually by electronic devices) of physical movement in a given area. The principal methods by which motion can be identified are infra-red detection and acoustical detection. Motion detection sensors are available which can easily detect movement and produce an alarm or switch on an image recording device. There are motion detectors which employ cameras connected to a computer and this detects certain objects moving.
The chief applications for such detection are (a) detection of unauthorized entry, (b) detection of cessation of occupancy of an area to extinguish lighting and (c) detection of a moving object which triggers a camera to record subsequent events. The motion detector is thus a lynchpin of electronic security systems, but is also a valuable tool in preventing illuminating unoccupied spaces.
A simple algorithm for motion detection by a fixed camera compares the current image with a reference image and simply counts the number of different pixels. Since images will naturally differ due to factors such as varying lighting, camera flicker, and CCD dark currents, pre-processing is useful to reduce the number of false positive alarms.
More complex algorithms are necessary to detect motion when the camera itself is moving, or when the motion of a specific object must be detected in a field containing other movement which can be ignored. An example might be a painting surrounded by visitors in an art gallery.
When motion detection is accomplished by natural organisms, we speak of motion perception.

[edit] References

Motion Detection Technologies
Motion Detection and Recognition Research
Retrieved from "http://en.wikipedia.org/wiki/Motion_detection"

2007-03-01 14:46:49 補充：
點走（投影）係要睇個programmer點寫個程式．由於我並唔識得個programmer，所以答唔到你．

2007-03-05 00:49:47 補充：
Testing

MTR果個未見過,但係海洋公園果個應該都係同一方法.
佢有野check住d圖案,投射出泥既圖案同原本應該出現既圖案對比一下,
就知有人庶左,做出反應,移動圖案.