rotation

问题 I am rotating an image with the following python code: from PIL import Image img = Image.open('banana.jpg') rotated = img.rotate(10) rotated.save('banana-rotated.jpg') This makes the following transformation: to As you can see, the background is black. This question asks how to fill the background with a specific color. However, I would like to fill the background with the color of the image. Because I need to rotate many images, I do not want to set the background to a fixed color. Is there

问题 I've got a Wordpress site with some CSS3 rules applied to some images that rotate the images and have a hover effect on rollover too. Problems are showing up in Safari & Firefox when you hover on and then off these images and I can't seem to locate any similar issues by people on the Interwebs. See http://tinyurl.com/3n2eude and hover on and then off the images (the slightly rotated ones): Member name goes blurry and then back to normal (Firefox) Member image border becomes jagged (Firefox) A

问题 After applying transform: rotate(90deg); the text is slightly shifted from it's normal position. Open this in Firefox : http://jsfiddle.net/42y89/. As you can see, the text appears shifted by 1px after it's rotated, which makes a big difference in this case. You can hover the boxes to see how this happens. On Chrome however it looks fine. It seems related to the font-size / line-height / anti-aliasing? I don't know... does anyone have any ideas? <div></div> div { width: 100px; height: 100px;

问题 Given a quaternion camera, how can I calculate its rotation when the player can walk on different surface normals (walls). I'm working on a game which allows the player to walk on ceilings and walls in 3D space. I've opted to use a quaternion camera system to avoid Gimbal Lock. Given a set of up(0,1,0), right(1,0,0), and forward(0,0,1) vectors, I construct a quaternion. The player rotates around the up vector for heading and around the right vector for pitch. Without changing gravity vectors,

问题 If I ignore the sordid details of quaternions algebra I think I understand the maths behind rotation and translation transformations. But still fail to understand what I am doing wrong. Why is my camera rolling once and for all!? :) And to be a bit more specific, how should I compute the camera View matrix from its orientation (rotation matrix)? I am writing a minimalistic 3d engine in Python with a scene Node class that handles the mechanics of rotation and translation of 3d objects. It has

问题 I'm converting a document which is created with a online editor. I need to be able to rotate the text using it's central point and not (0,0). Since Image rotates using the centre I assumed this would work but it doesn't. Anyone has a clue how to rotate text using the central point in itext? float fw = bf.getWidthPoint(text, textSize); float fh = bf.getAscentPoint(text, textSize) - bf.getDescentPoint(text, textSize); PdfTemplate template = content.createTemplate(fw, fh); Rectangle r = new

问题 i am trying to rotate a 89x89 image inside the QLabel Widge. #include "header.h" disc::disc(QWidget *Parent) : QWidget(Parent) { orig_pixmap = new QPixmap(); rotate = new QLabel(this); showDegrees = new QLabel(this); orig_pixmap->load("pic.png"); degrees = 0; rotate->resize(89,89); rotate->move(100,10); rotate->setStyleSheet("QLabel{background-color:red;}"); showDegrees->resize(100,100); showDegrees->move(400,0); } void disc::rotate_disc() { QString string; degrees++; if(degrees == 360)

问题 PREREQUISITES Let me start the question by providing some boilerplate code we'll use to play around: mcve_framework.py: from OpenGL.GL import * from OpenGL.GLU import * from OpenGL.GLUT import * import glm from glm import cross, normalize, unProject, vec2, vec3, vec4 # -------- Camera -------- class BaseCamera(): def __init__( self, eye=None, target=None, up=None, fov=None, near=0.1, far=100000, delta_zoom=10 ): self.eye = eye or glm.vec3(0, 0, 1) self.target = target or glm.vec3(0, 0, 0)

问题 How do I generate a transformation matrix for rotating points/others by the angle between two lines/vectors/directions in CGAL? 2D is what I need. 3D is what I love. 回答1: According to the manual you have these tools to work with: Aff_transformation_2<Kernel> t ( const Rotation, Direction_2<Kernel> d, Kernel::RT num, Kernel::RT den = RT(1)) approximates the rotation over the angle indicated by direction d, such that the differences between the sines and cosines of the rotation given by d and

问题 With reference to this programming game I am currently building. Thanks to the answers from this post, I am now able to find the x-y coordinates of all the points of the rectangles (even when rotated), and Collision-Detection with Walls is almost working perfectly now. Now I need to implement collision detection with the bots themselves (cause obviously, there will be more than one bot in the Arena). Square-Square Collision Detection (Non-rotated) is not valid in this case because the bots