rotation

问题 I'm using PostgresSQL 9.5 to generate a rectangle (geometric type BOX). That works fine SELECT Box(Point(-50, -100), Point(50, 100)) ; -- this works Then I try to rotate that box around the origin (its center point). The rotation function is both * Scaling/rotation box '((0,0),(1,1))' * point '(2.0,0)' / Scaling/rotation box '((0,0),(2,2))' / point '(2.0,0)' where the x-point is the scaling factor (2.0 in this example) and the y-point is the rotation radians (0 in this example). To check that

问题 I have colliders where i can turn to the sides and i want camera to rotate as a player turn to the side. I'm using Mathf.LerpAngle for that, but when I press the key for turn to side, camera is rotating in loop. How can I make rotation stop? The problem is that everytime I turn player should go -90 degrees to the left +90 to the right and there will be more turns so i can't use functions for setting rotation. I was already trying to make it stop by that if statement with (lAngle > 90f) float

问题 I was trying to create a OpenGL version of an old plasma 8bit effect animation in DOS but I am stuck. Since almost every OpenGL program has included something to generate a palette for Win32 I thought it would not be that hard to apply palette animation on my old program. My purpose is to generate a texture with color indices that does not change and a palette that is rotating. After digging into the web this weekend I am still not able to fix it. I cannot even display a texture with one

问题 I would like to continuously rotate an image efficiently -- it must work smoothly on mobile browsers. I am currently using CSS3 animation. I would like to be able to control the CSS functionality using javascript (start, stop, set rotation speed, easing for extra credit). Here is what I have so far to do the rotation itself. JS needed. Thanks! HTML: <img class="image" src="https://brainful.s3.amazonaws.com/assets/images/twoStates/circle.png" alt=""> CSS: .image { position: absolute; top: 50%;

问题 I have an issue with items rotating. I have a point and a triangle which needs to be rotated with its apex point towards the taregt point. The right side of the picture represents how it is should to be, and the left side represents how it works. Red dashed arrows represent motion, the triangle moves along its arrow. Green dashed arrow represent rotation, the triangle should rotates along its arrow. How do I do calculations: calculating desired velocity aka direction velocity(direction) =

问题 I'm using Matlab 2013a on Windows 7 Pro 64 bit. In 2010 (using a different version of Matlab), I wrote the following code to calculate a 3x3 rotation matrix C=rotate (omega, i, w); R=C*Ro; where omega, i, and w are rotation angles in radians. On my current system, giving the example input of omega = i = w = 0, C will be a 3x3 identity matrix. If I copy the code into another directory that I wrote in the past few months, the same code will result in the following error. Error using rotate Too

问题 I need some help with this. I made a nice web kit animation for one of the elements on my site. It is supposed to rotate 7 degrees back and forth continuously. Unfortunately it works only in Chrome. Here is the code: #brk { background: url("../images/brk.png"); width: 118px; height: 54px; display: block; position: relative; top: 65px; left: 93px; -webkit-animation: brk-spin 3s infinite linear; -moz-animation: brk-spin 3s infinite linear; -o-animation: brk-spin 3s infinite linear; -ms

问题 I have a planet and a moon. The moon is parented to a dummy object, which is located at the center of the planet (essentially 0,0,0). The moon is free to rotate around (to any position on) the planet. It should maintain a constant distance from the planet. I have a specific point in mind that I want to rotate the moon to, though it needs to stay upright. That is, the moon should consistently point "up" relative to the planet's surface. Basically it's like a "moveTo" script only in my case the

问题 So I used tutorials from http://zetcode.com/tutorials/javagamestutorial/basics/ and I'm using the Donut program. For anyone unfamiliar it does this http://zetcode.com/img/gfx/javagames/donut.png I want to make the ellipses rotate around the center of the window, to make it look like it's moving in a circle. The code so far is the code from the webpage. package donut; import javax.swing.*; import java.awt.*; import java.awt.geom.AffineTransform; import java.awt.geom.Ellipse2D; public class

问题 I have the following code... public class Point { private double x; private double y; static private final double RADTODEG = 180.0d / Math.PI ; static private final double DEGTORAD = Math.PI / 180.0d; /** * Rotates the point by a specific number of radians about a specific origin point. * @param origin The origin point about which to rotate the point * @param degrees The number of radians to rotate the point */ public void rotateByRadians(Point origin, double radians) { double cosVal = Math