所以,情况是Object1和它的名字OBJECT1先进入流水线处理,进行坐标变换—— 它们(顶点)先被左乘一个模型矩阵(可能是单位阵也可能是其他,看你RenderObject1里面有无移动旋转缩放类操作了),然后被左乘一个视图矩阵(由相机camera.Look(),实质即gluLookAt设定和操作),然后被左乘投影矩阵(由gluPerspective设定和操作),然后又...
Tutorial 29 - 3D Pickingogldev.org/www/tutorial29/tutorial29.html Picking with an OpenGL hack...
深入理解OpenGL拾取模式（OpenGL Picking） 在用OpenGL进行图形编程的时候，通常要用鼠标进行交互操作，比如用鼠标点选择画面中的物体，我们称之为拾取(Picking)，在网上看了很多OpenGL拾取的文章，但大多是只是介绍在OpenGL中如何拾取，如何利用OpenGL提供的一系列函数来完成拾取，最多再简单介绍下OpenGL的名字栈(Name ...
In order to meet the need of real-time information query in virtual roaming system,the problems of 3Dvirtual object picking based on OpenGL has been studied in this paper.By means of analyzing the coordinate and transformation in OpenGL,the basic process of object picking in 3Dspace has been ...
原文地址:http://www.zwqxin.com/archives/opengl/opengl-picking-what.html 假设用户是通过鼠标左键单击来选择场景物件的。先说说一般游戏引擎里的“射线检测”实现思路,也就是在用户拾取物件,点击渲染窗口(屏幕)上的相应的某一点的时候,激发一条从相机位置(眼睛)过该点的射线,这条射线反映在世界空间中,就是“...
class PickingTexture { public: PickingTexture(); ~PickingTexture(); bool Init(unsigned int WindowWidth, unsigned int WindowHeight); void EnableWriting(); void DisableWriting(); struct PixelInfo { unsigned int ObjectID; unsigned int DrawID; ...
1) Screen mouse picking: We could emit a 3D ray from the current viewer position and do intersection test for this ray and those pick-able objects. With this method, we could pick the objects that we want on the screen mouse cursor. There is one demo under the DirectX install directory...
x = [[item objectForKey:@"posX"] floatValue]; z = [[item objectForKey:@"posZ"] floatValue]; IMPoint3D playerPos; playerPos.x = x; playerPos.z = z; playerPos.y = 1; CGPoint screenPositionOfThisCube ; screenPositionOfThisCube = [self getScreenCoorOfPoint:playerPos]; ...
public static void createColorPickingTexture(ColorPickerInfo pickerInfo) { final ObjectColorPicker picker = pickerInfo.getPicker(); final ByteBuffer pixelBuffer = ByteBuffer.allocateDirect(4); pixelBuffer.order(ByteOrder.nativeOrder()); GLES20.glReadPixels(pickerInfo.getX(), picker.mRenderer.getDefault...
The OpenGL API provides a mechanism for picking objects in a 3D scene. This tutorial will show you how to detect which objects are bellow the mouse or in a square region of the OpenGL window. The steps involved in detecting which objects are at the location where the mouse was clicked are...