rotation

问题 The program I am writing draws multiple stars on the screen and gives them random directions and speeds. The stars will bounce off the edges of the panel and stay inside. I need to have the stars rotating as they are moving. I have tried so many things and I cannot figure it out. Below is the code I use to draw the stars and move them. Additional Information: -the stars are in a collection called "stars" -there are two classes that I wrote, "Star" and "MyJPanel" Set the points: (in Star class

问题 The program I am writing draws multiple stars on the screen and gives them random directions and speeds. The stars will bounce off the edges of the panel and stay inside. I need to have the stars rotating as they are moving. I have tried so many things and I cannot figure it out. Below is the code I use to draw the stars and move them. Additional Information: -the stars are in a collection called "stars" -there are two classes that I wrote, "Star" and "MyJPanel" Set the points: (in Star class

问题 I'm making a ThreeJS Demo, and I'm currently using the arrow keys to rotate the camera. At first things seem to work out ok. I can successfully rotate up and down, and left and right. However, when I turn to the left, and then try to rotate up or down, it rotates up and down, but NOT relative to my current position - it acts as if I hadn't rotated left at all. Here's my current render code: function render() { plane.rotation.y += 0.005; cube.rotation.z += 0.01; cube.rotation.y += 0.01; if

问题 i have this problem when my Sprite rotation origin is fixed at top left corner of window (same with sprite.Draw and sprite.Draw2D ) Either way if i change rotation center it's still at top left. I need sprite to rotate around its Z axis. Edit: I have tried this: hereMatrix pm = Matrix.Translation(_playerPos.X + 8, _playerPos.Y + 8, 0); sprite.Transform = Matrix.RotationZ(_angle) * pm; sprite.Draw(playerTexture, textureSize, new Vector3(8, 8, 0), new Vector3(_playerPos.X, _playerPos.Y, 0),

问题 I'm implementing a simple camera system in OpenGL. I set up gluPerspective under the projection matrix and then use gluLookAt on the ModelView matrix. After this I have my main render loop which checks for keyboard events and, if any of the arrow keys are pressed, modifies angular and forward speeds (I only rotate through the y axis and move through the z (forwards)). Then I move the view using the following code (deltaTime is the amount of time since the last frame was rendered in seconds,

问题 I have a custom camera overlay that, like all camera views, is default in landscape mode. I have some orientation change logic that detect when the orientation changes so I can rotate the buttons and views that I have placed. Also, I have edited the shouldAutoRotateInterfaceTo method so it does not rotate while the camera is on: - (BOOL)shouldAutorotateToInterfaceOrientation (UIInterfaceOrientation)interfaceOrientation { if (cameraIsOn) { return NO; } return (interfaceOrientation ==

问题 I have a 2D image of 512x512 pixels that I would like to rotate with a certain angle at a certain origin (rotation center). All this time, I uses Scipy to rotate images with its rotate method. But, I got stumbled because the rotation always done around the center of the image. With 512x512 pixels the rotation center should be around point (x,y) 128,128. How can I rotate the image with a custom rotation center, let's say around (x,y) 20,128? 回答1: If OpenCV is not an option, you can do image

问题 Anyone who's trying the newest iOS 6 beta(version 2 or 3) has the same experience of auto rotation not working? I am not using storyboard but pure navigation control: self.navController = [[UINavigationController alloc] initWithRootViewController:self.viewController]; [self.window addSubview:navController.view]; And have: - (BOOL)shouldAutorotateToInterfaceOrientation: ](UIInterfaceOrientation)interfaceOrientation { if ([[UIDevice currentDevice] userInterfaceIdiom] ==

问题 Code 1 where flipping vertically and/or horizontally does not affect axes() ; Code 2 where proposed solution does not yield the expected output close all; clear all; clc; x = [5 8]; y = [3 6]; C = [0 2 4 6; 8 10 12 14; 16 18 20 22]; C2 = C(:,end:-1:1,:); %# horizontal flip C3 = C(end:-1:1,:,:); %# vertical flip C4 = C(end:-1:1,end:-1:1,:); %# horizontal+vertical flip % https://stackoverflow.com/a/4010203/54964 subplot(2,2,1), imagesc(x,y,C) subplot(2,2,2), imagesc(x,y,C2) subplot(2,2,3),

问题 Code 1 where flipping vertically and/or horizontally does not affect axes() ; Code 2 where proposed solution does not yield the expected output close all; clear all; clc; x = [5 8]; y = [3 6]; C = [0 2 4 6; 8 10 12 14; 16 18 20 22]; C2 = C(:,end:-1:1,:); %# horizontal flip C3 = C(end:-1:1,:,:); %# vertical flip C4 = C(end:-1:1,end:-1:1,:); %# horizontal+vertical flip % https://stackoverflow.com/a/4010203/54964 subplot(2,2,1), imagesc(x,y,C) subplot(2,2,2), imagesc(x,y,C2) subplot(2,2,3),