perspectivecamera

问题 I hame some image with plane which have perspective transform. I need to detect center of each white rhombus or rhombus itself. Here is examples: As I unserstand the problem can be solved by simple template matching if we rectify image, but I need to do it automatically. Is there any functions in OpenCV suitable for this task? Any other ideas? 回答1: Here are two quick tests I just did without correcting the perspective issue. Pure mathematical morphology : Extract the red channel Big white top

问题 Simply, I am just trying to show a 3d point but nothing show on! How to show it? what is wrong in the code below, anybody can help? init: void init(void) { glClearColor(0.0, 0.0, 0.0, 0.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glOrtho(-200, 0.0, -50, 100, 70, 300); } display: void display(void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glColor3f(1.0, 1.0, 1.0); glPointSize(2); glBegin(GL_POINTS); glVertex3f(-120.0, 25.0, 0.0)

来源： https://stackoverflow.com/questions/63084469/when-and-how-does-opengl-calculate-f-depthdepth-value

来源： https://stackoverflow.com/questions/63084469/when-and-how-does-opengl-calculate-f-depthdepth-value

来源： https://stackoverflow.com/questions/23187452/javafx-separate-perspective-view-on-a-3d-chess-field

问题 I would like to recreate the Three.js OrbitControl movement without the click & drag , i.e. simply making the camera following mouse movement. I tried to recreate it from scratch, but it was too much effort as the problem is that the camera moves on three axis, not just two. I'm pretty sure some has done before. Specifically I would like the camera to move around the scene origin keeping the same distance from it. 回答1: I had the same requirement as OP. This is how I solved it, with help from

问题 watching Ken Joy's Computer Graphics lectures on youtube. One thing I'm confused about is after he gets the cube from the camera space to clip space, from my calculations the cube doesn't look like that. I expected the cube to look like that pink parallelogram in my picture, if we assume the Z of the front-face of the cube to be -4/3 and the back-face to be -2 then the Ws come out to be 4/3 and 2 respectively. So can someone explain how after multiplying by the viewing matrix, the cube comes

问题 I am trying to make a 3D viewer for building models. We have the model loaded and are trying to make some sort of interaction with the model. Therefor we are using OrbiControls for rotating, panning and zooming the model. We want to have the behaviour in the viewer that when a user clicks and drags (thus rotating), the rotation center is at the point of the building where the user clicks. I thought I was wise by changing the target of the OrbitControl as such: control.target.set(newX, newY,

问题 I am trying to make a 3D viewer for building models. We have the model loaded and are trying to make some sort of interaction with the model. Therefor we are using OrbiControls for rotating, panning and zooming the model. We want to have the behaviour in the viewer that when a user clicks and drags (thus rotating), the rotation center is at the point of the building where the user clicks. I thought I was wise by changing the target of the OrbitControl as such: control.target.set(newX, newY,

问题 I am trying to make a 3D viewer for building models. We have the model loaded and are trying to make some sort of interaction with the model. Therefor we are using OrbiControls for rotating, panning and zooming the model. We want to have the behaviour in the viewer that when a user clicks and drags (thus rotating), the rotation center is at the point of the building where the user clicks. I thought I was wise by changing the target of the OrbitControl as such: control.target.set(newX, newY,