perspective

问题 I wanna make the OpenGL program can present images and warp the images presented. Although I achieved image rendering using OpenGL, I don't know how to warp an image. An warpable example I want is (Reference): But a picture I got is: As I know, this problem is related to perspective correction mapping. But I don't know about that well. Here is my source code. void imageRender(Shader initShader, Shader imgShader, char *path){ glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST); float positions

问题 I am confused about perspective projection. Here is the scenario that is confusing me. My frustrum's front plane is basically positioned at at positive z-axis and the back plane at a negative axis and rotated about some deg along the posive z-axis. Now, whenever I go through examples I see that the near and the far plane are all present in the negative z axis. My approach in this case was basically something like: glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustrum(-xval,+xval,-yval,

问题 I am confused about perspective projection. Here is the scenario that is confusing me. My frustrum's front plane is basically positioned at at positive z-axis and the back plane at a negative axis and rotated about some deg along the posive z-axis. Now, whenever I go through examples I see that the near and the far plane are all present in the negative z axis. My approach in this case was basically something like: glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustrum(-xval,+xval,-yval,

问题 I'm trying to achieve a kind of origami transition on two UIView using only layer capabilities. The idea is to fold two views with a perspective effect. Both views have a perspective, the transition is defined by a rotation on each view, as well as a translation on one view such that this view seems to be attached to the other one. The issue is that the view overlaps one another in the middle of the transition. I don't want to use a zPosition to visually avoid this overlapping, I really want

问题 What I am trying to do is to make the people's sizes in the output image all the same. So I performed a perspective transformation so that the viewing angle is right above the scene. The scene picture is showing below: The functions I am using is cv2.getPerspectiveTransform and cv2.warpPerspective, and this method need 4 points on the input image and corresponding points on the output image. For the 4 points on the output image, i always choose the four corners. However it's very hard to

问题 When reset Perspective code is done as in the given link https://www.eclipse.org/forums/index.php/m/1209165/srch=reset+perspective+in+e4#msg_1209165 and code called is The code is as follows public class ResetPerspective { // private static final String MAIN_PERSPECTIVE_STACK_ID = "MainPerspectiveStack"; @Execute public void execute(@Named(IServiceConstants.ACTIVE_SHELL) Shell shell, EModelService modelService, MApplication app, EPartService partService) { MWindow window = (MWindow)

问题 I am using a combination of Opencv and python to turn the perspective view of this image to a birds-eye view (top view) to remove the perspective view I wrote this code Image1 = cv2.imread('/path to image/im.jpg') cv2.circle(Image1,(867,652),5,(0,0,255),-1) cv2.circle(Image1,(1020,580),5,(0,0,255),-1) cv2.circle(Image1,(1206,666),5,(0,0,255),-1) cv2.circle(Image1,(1057,757),5,(0,0,255),-1) pts1=np.float32([[867,652],[1020,580],[1206,666],[1057,757]]) pts2=np.float32([[448,609],[580,607],[582

问题 Is it possible to make perspective image transformation in html5 canvas? I am using EaselJS right now and can't find a solution for my need. 回答1: I don't tried the easel.js yet, but every image transformation is done with matrix operations: translate, rotate, skew etc. Looking on the easel.js source code there is a Matrix2D class, and the documentation to it: http://www.createjs.com/Docs/EaselJS/Matrix2D.html. For a perspective transformation you need to use rotation , scaling and skewing .

问题 Is it possible to make perspective image transformation in html5 canvas? I am using EaselJS right now and can't find a solution for my need. 回答1: I don't tried the easel.js yet, but every image transformation is done with matrix operations: translate, rotate, skew etc. Looking on the easel.js source code there is a Matrix2D class, and the documentation to it: http://www.createjs.com/Docs/EaselJS/Matrix2D.html. For a perspective transformation you need to use rotation , scaling and skewing .

问题 Prologue This Q&A is a remake of: How to highlight 3D perspective camera view (frustrum) on topside 2D minimap? which was closed (and failed first reopening cycle) due to lack of info and no response of the original author. However I think this is an interesting question though so I decided to Ask&Answer this myself (this time with all the needed specs). Question Let assume our world is a uniform rectangular square grid (represented by 2D array of tiles) mapped on a plane (let say plane XY (