Search Results

Search found 1603 results on 65 pages for 'coordinate transformation'.

Page 6/65 | < Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >

• getting bone base and tip positions from a transform matrix?

  - by ddos

  I need this for a Blender3d script, but you don't really need to know Blender to answer this. I need to get bone head and tip positions from a transform matrix read from a file. The position of base is the location part of the matrix, length of the bone (distance from base to tip) is the scale, position of the tip is calculated from the scale (distance from bone base) and rotation part of the matrix. So how to calculate these? bone.base([x,y,z]) # x,y,z - floats bone.tip([x,y,z])

  Read the article

• Precision loss when transforming from cartesian to isometric

  - by Justin Skiles

  My goal is to display a tile map in isometric projection. This tile map has 25 tiles across and 25 tiles down. Each tile is 32x32. See below for how I'm accomplishing this. World Space World Space to Screen Space Rotation (45 degrees) Using a 2D rotation matrix, I use the following: double rotation = Math.PI / 4; double rotatedX = ((tileWorldX * Math.Cos(rotation)) - ((tileWorldY * Math.Sin(rotation))); double rotatedY = ((tileWorldX * Math.Sin(rotation)) + (tileWorldY * Math.Cos(rotation))); World Space to Screen Space Scale (Y-axis reduced by 50%) Here I simply scale down the Y value by a factor of 0.5. Problem And it works, kind of. There are some tiny 1px-2px gaps between some of the tiles when rendering. I think there's some precision loss somewhere, or I'm not understanding how to get these tiles to fit together perfectly. I'm not truncating or converting my values to non-decimal types until I absolutely have to (when I pass to the render method, which only takes integers). I'm not sure how to guarantee pixel perfect rendering precision when I'm rotating and scaling on a level of higher precision. Any advice? Do I need to supply for information?

  Read the article

• how to transform child elements position into a world position

  - by MrGreg

  So Im making a 2d space game and I have a bunch of spaceships that have turrets. Objects have a position and orientation, the ships being in world coordinates while the turrets are children and coordinates are relative to their parents. How do I efficiently calculate the position of a turret in world coordinates (i.e. when it fires and I need to know where to place a bullet in the world)? Calculating the turrets orientation is trivial - I just add the turrets relative angle to its parents. For position though, I guess I could do a bunch of trigonometry but this MUST be a common problem with a good/fast general solution? Should I be relearning how to do matrix math again? :) btw - Im creating the game in javascript+canvas but its the math/algorithm im interested in here Cheers, Greg

  Read the article

• Optimizing hierarchical transform

  - by Geotarget

  I'm transforming objects in 3D space by transforming each vector with the object's 4x4 transform matrix. In order to achieve hierarchical transform, I transform the child by its own matrix, and then the child by the parent matrix. This becomes costly because objects deeper in the display tree have to be transformed by all the parent objects. This is what's happening, in summary: Root -- transform its verts by Root matrix Parent -- transform its verts by Parent, Root matrix Child -- transform its verts by Child, Parent, Root matrix Is there a faster way to transform vertices to achieve hierarchical transform? What If I first concatenated each transform matrix with the parent matrices, and then transform verts by that final resulting matrix, would that work and wouldn't that be faster? Root -- transform its verts by Root matrix Parent -- concat Parent, Root matrices, transform its verts by Concated matrix Child -- concat Child, Parent, Root matrices, transform its verts by Concated matrix

  Read the article

• Translate along local axis

  - by Aaron

  I have an object with a position matrix and a rotation matrix (derived from a quaternion, but I digress). I'm able to translate this object along world-relative vectors, but I'm trying to figure out how to translate it along local-relative vectors. So if the object is tilted 45 degrees around its Z-axis the vector (1, 0, 0) would make it move to the upper right. For world-space translations I simply turn the movement vector into a matrix and multiply it by the position matrix: position_mat = translation_mat * position_mat. For local-space translations I'd think I'd have to use the rotation matrix into that formula, but I see the object spin around instead when I apply a translation over time no matter where I multiply the rotation matrix.

  Read the article

• Using multiplication and division with delta time

  - by tesselode

  Using delta time with addition and subtraction is easy. player.x += 100 * dt However, multiplication and division complicate things a bit. For example, let's say I want the player to double his speed every second. player.x = player.x * 2 * dt I can't do this because it'll slow down the player (unless delta time is really high). Division is the same way, except it'll speed things way up. How can I handle multiplication and division with delta time?

  Read the article

• Why do we move the world instead of the camera

  - by sharethis

  I heard that in an OpenGL game what we do to let the player move is not to move the camera but to move the whole world around. For example here is an extract of this tutorial: http://open.gl/transformations In real life you're used to moving the camera to alter the view of a certain scene, in OpenGL it's the other way around. The camera in OpenGL cannot move and is defined to be located at (0,0,0) facing the negative Z direction. That means that instead of moving and rotating the camera, the world is moved and rotated around the camera to construct the appropriate view. Why do we do that?

  Read the article

• How to work with edge Texture

  - by XzenTorXz

  Im not sure if i use the right terms, but im not able to find something to start with. Im trying to develop a little HTML5 game. I have a ground with a texture and now I want to make a surrounding texture. The texture is an image wich should be bend around the ground. At the moment im using easelJS for display my images/textures. So im looking for some sort of Tutorial/Script/Advice. Im not even sure if I can bend a image in javascript. So the worst case I can think of is split the image in 100 pieces and then put it back together and rotate each piece. for example like this:

  Read the article

• How do I rotate a sprite with ccbezierTo in cocos2d-x?

  - by user1609578

  In cocos2d-x, I move a sprite with ccbezierTo like this: // use for ccbezierTo bezier.controlPoint_1 = ccp(m_fish->getPositionX() + 200, visibleSize.height/2 + 300); bezier.controlPoint_2 = ccp(m_fish->getPositionX() + 400, visibleSize.height/2 - 300); bezier.endPosition = ccp(m_fish->getPositionX() + 600,visibleSize.height/2); bezier1.controlPoint_1 = ccp(m_fish->getPositionX() + 800, visibleSize.height/2 + 300); bezier1.controlPoint_2 = ccp(m_fish->getPositionX() + 1000, visibleSize.height/2 - 300); bezier1.endPosition = ccp(m_fish->getPositionX() + 1200,visibleSize.height/2); bezierForward = CCBezierTo::create(6, bezier); nextBezier = CCBezierTo::create (6,bezier1); m_fish->runAction(CCSequence::create( bezierForward, nextBezier, NULL)); How can I make my sprite rotate while moving it with CCBezierTo?

  Read the article

• Translating multiple objects in GUI based on average position?

  - by user1423893

  I use this method to move a single object in 3D space, it accounts for a local offset based on where the cursor ray hits the widget and the center of the widget. var cursorRay = cursor.Ray; Vector3 goalPosition = translationWidget.GoalPosition; Vector3 position = cursorRay.Origin + cursorRay.Direction * grabDistance; // Constrain object movement based on selected axis switch (translationWidget.AxisSelected) { case AxisSelected.All: goalPosition = position; break; case AxisSelected.None: break; case AxisSelected.X: goalPosition.X = position.X; break; case AxisSelected.Y: goalPosition.Y = position.Y; break; case AxisSelected.Z: goalPosition.Z = position.Z; break; } translationWidget.GoalPosition = goalPosition; Vector3 p = goalPosition - translationWidget.LocalOffset; objectSelected.Position = p; I would like to move multiple objects based on the same principle and using a widget which is located at the average position of all the objects currently selected. I thought that I would have to translate each object based on their offset from the average point and then include the local offset. var cursorRay = cursor.Ray; Vector3 goalPosition = translationWidget.GoalPosition; Vector3 position = cursorRay.Origin + cursorRay.Direction * grabDistance; // Constrain object movement based on selected axis switch (translationWidget.AxisSelected) { case AxisSelected.All: goalPosition = position; break; case AxisSelected.None: break; case AxisSelected.X: goalPosition.X = position.X; break; case AxisSelected.Y: goalPosition.Y = position.Y; break; case AxisSelected.Z: goalPosition.Z = position.Z; break; } translationWidget.GoalPosition = goalPosition; Vector3 p = goalPosition - translationWidget.LocalOffset; int numSelectedObjects = objectSelectedList.Count; for (int i = 0; i < numSelectedObjects; ++i) { objectSelectedList[i].Position = (objectSelectedList[i].Position - translationWidget.Position) + p; } This doesn't work as the object starts shaking, which I think is because I haven't accounted for the new offset correctly. Where have I gone wrong?

  Read the article

• OpenGL: Move camera regardless of rotation

  - by Markus

  For a 2D board game I'd like to move and rotate an orthogonal camera in coordinates given in a reference system (window space), but simply can't get it to work. The idea is that the user can drag the camera over a surface, rotate and scale it. Rotation and scaling should always be around the center of the current viewport. The camera is set up as: gl.glMatrixMode(GL2.GL_PROJECTION); gl.glLoadIdentity(); gl.glOrtho(-width/2, width/2, -height/2, height/2, nearPlane, farPlane); where width and height are equal to the viewport's width and height, so that 1 unit is one pixel when no zoom is applied. Since these transformations usually mean (scaling and) translating the world, then rotating it, the implementation is: gl.glMatrixMode(GL2.GL_MODELVIEW); gl.glLoadIdentity(); gl.glRotatef(rotation, 0, 0, 1); // e.g. 45° gl.glTranslatef(x, y, 0); // e.g. +10 for 10px right, -2 for 2px down gl.glScalef(zoomFactor, zoomFactor, zoomFactor); // e.g. scale by 1.5 That however has the nasty side effect that translations are transformed as well, that is applied in world coordinates. If I rotate around 90° and translate again, X and Y axis are swapped. If I reorder the transformations so they read gl.glTranslatef(x, y, 0); gl.glScalef(zoomFactor, zoomFactor, zoomFactor); gl.glRotatef(rotation, 0, 0, 1); the translation will be applied correctly (in reference space, so translation along x always visually moves the camera sideways) but rotation and scaling are now performed around origin. It shouldn't be too hard, so what is it I'm missing?

  Read the article

• Transforms in Box2D

  - by user1264811

  I'm attempting to implement a camera in my game. I had it working for regular objects, but I began using Box2D and obviously things changed a bit. I have a Body object that I want to draw at the center of the screen. Basically what I'm doing is subtracting the viewportX and viewportY to the Body. I use this code that currently is not working as it should: public void paint(Graphics2D g, int viewportX, int viewportY) { Transform xf = new Transform(); // m_body is the Body object xf.set(m_body.getTransform()); // Here what I attemp to do is take the transform and alter it // by the viewportX and Y, which is something like **-240, -150**. // Why is it negative? Because an object has coordinates 500, 300 would be displayed // at 160, 150 when the subtraction is done. // With the DrawUtils.toScale(), it's just how I convert the units from JBox2D units // to my units. Vec2 v = Transform.mulTrans(xf, new Vec2(DrawUtils.toScale(-viewportX), DrawUtils.toScale(-viewportY))); // Set the new transform to the new vector. Keep the old angle. xf.set(v, xf.q.getAngle()); g.setColor(Color.white); // I know for a fact that the following method works 100%. It correctly displays // my object, just that it doesn't follow it. for (Fixture f = m_body.getFixtureList(); f != null; f = f.getNext()) DrawUtils.drawShape(f, xf); } Hopefully I didn't over comment this and you understand my problem. I don't want to alter the actual physics position of the object, I just want to display it in the center.

  Read the article

• php PHPExcel split Excel cell coordinate

  - by Shiro

  currently, I used PHPExcel to import excel file, there is a function $cell-getCoordinate(); I would like to ask any solution for split the cell coordinate alphabet and integer? e.g A1, A2, I need to know currently which row, and until which column. I do some research about split, but not luck for it. Any idea?

  Read the article

• Adding distance to a GPS coordinate

  - by fgs

  Hi! I'm trying to generate some points at random distances away from a fixed point using GPS. How can I add distance in meters to a GPS coordinate? I've looked at UTM to GPS conversion but is there a simpler method to achieve this? I'm working on Android platform just in case. Cheers, fgs

  Read the article

• OpenGL Coordinate system confusion

  - by user146780

  Maybe I set up GLUT wrong. Basically I want verticies to be reletive to their size in pixels. Ex:right now if I create a hexagon, it hakes up the whole screen even though the units are 6. #include <iostream> #include <stdlib.h> //Needed for "exit" function #include <cmath> //Include OpenGL header files, so that we can use OpenGL #ifdef __APPLE__ #include <OpenGL/OpenGL.h> #include <GLUT/glut.h> #else #include <GL/glut.h> #endif using namespace std; //Called when a key is pressed void handleKeypress(unsigned char key, //The key that was pressed int x, int y) { //The current mouse coordinates switch (key) { case 27: //Escape key exit(0); //Exit the program } } //Initializes 3D rendering void initRendering() { //Makes 3D drawing work when something is in front of something else glEnable(GL_DEPTH_TEST); } //Called when the window is resized void handleResize(int w, int h) { //Tell OpenGL how to convert from coordinates to pixel values glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); //Switch to setting the camera perspective //Set the camera perspective glLoadIdentity(); //Reset the camera gluPerspective(45.0, //The camera angle (double)w / (double)h, //The width-to-height ratio 1.0, //The near z clipping coordinate 200.0); //The far z clipping coordinate } //Draws the 3D scene void drawScene() { //Clear information from last draw glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); //Reset the drawing perspective glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); glBegin(GL_POLYGON); //Begin quadrilateral coordinates //Trapezoid glColor3f(255,0,0); for(int i = 0; i < 6; ++i) { glVertex2d(sin(i/6.0*2* 3.1415), cos(i/6.0*2* 3.1415)); } glEnd(); //End quadrilateral coordinates glutSwapBuffers(); //Send the 3D scene to the screen } int main(int argc, char** argv) { //Initialize GLUT glutInit(&argc, argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH); glutInitWindowSize(400, 400); //Set the window size //Create the window glutCreateWindow("Basic Shapes - videotutorialsrock.com"); initRendering(); //Initialize rendering //Set handler functions for drawing, keypresses, and window resizes glutDisplayFunc(drawScene); glutKeyboardFunc(handleKeypress); glutReshapeFunc(handleResize); glutMainLoop(); //Start the main loop. glutMainLoop doesn't return. return 0; //This line is never reached } How can I make it so that a polygon of 0,0 10,0 10,10 0,10 defines a polygon starting at the top left of the screen and is a width and height of 10 pixels? Thanks

  Read the article

• Actionscript change default coordinate

  - by Comma

  I have a sprite inside another sprite SpriteB is inside SpriteA I would like to change the default coordinate(top left corner) to say 250,10 When SpriteB.x = 0, SpriteB.y = 0 puts SpriteB to 250,10 in SpriteA Is this possible?

  Read the article

• VS 2010 web.config transformation

  - by Fabian Vilers

  Hi all, I need help on web.config transformation as I'm trying to do something not documented. My web.config has an empty connectionStrings element. In debug, I'd like the transformation tool to add a configSource="file.local" to the connectionStrings element. But in release, I'd like it to add a connectionString element. So, to summarize, I have <connectionStings> </connectionStings> And I need to transform it to <connectionStings configSource="file.local"> </connectionStings> And to: <connectionStings> <clear/> <add name="Abc" connectionSting="bla bla bla" provider="xxx" /> </connectionStings> Anybody has done this yet? Thanks in advance, Fabian

  Read the article

• Lookup Transformation Task

  - by Sreejesh Kumar

  What is the main purpose of Lookup Transformation Task ?

  Read the article

• haar transformation on an image

  - by kabatusuka

  hello, i need some help with haar transformation, i have to apply it on an image. My math is bad, my english not all that awesome and i find it hard to understand from articles on the internet. I found this page http://www.cs.ucf.edu/~mali/haar/haar.cpp where the haar transformation is applied on 2d matrix. I suppose if i give image pixels matrix in there, it should work? im confused about this stuff, could someone enlighten me a bit please? Thank you!

  Read the article

• Mismatched coordinate systems in LWJGL with Mouse and Textures

  - by Braains

  I'm not really sure how to expand on this other than to say that it appears that my LWJGL seems to have different coordinate systems for the Mouse and for painting Textures. It seems that Textures have the usual Java2D way of putting (0, 0) in the upper-left corner, while the Mouse goes by the more sensible way of having the origin in the lower-left corner. I've checked my code a bunch but I don't see anything modifying the values between where I read them and where I use them. It's thrown me for a loop and I can't quite figure it out. I'll post all the code that involves the Mouse input and Texture painting for you guys to look at. private static void pollHelpers() { while(Mouse.next()) { InputHelper.acceptMouseInput(Mouse.getEventButton(), Mouse.getEventX(), Mouse.getEventY()); } while (Keyboard.next()) { if (Keyboard.getEventKeyState()) { InputHelper.acceptKeyboardInput(Keyboard.getEventKey(), true); } else { InputHelper.acceptKeyboardInput(Keyboard.getEventKey(), false); } } } public static void acceptMouseInput(int mouseButton, int x, int y) { for(InputHelper ie: InputHelper.instances) { if(ie.checkRectangle(x, y)) { ie.sendMouseInputToParent(mouseButton); } } } private void sendMouseInputToParent(int mouseButton) { parent.onClick(mouseButton); } public boolean checkRectangle(int x, int y) { //y = InputManager.HEIGHT - y; See below for explanation return x > parent.getX() && x < parent.getX() + parent.getWidth() && y > parent.getY() && y < parent.getY() + parent.getHeight(); } I put this line of code in because it temporarily fixed the coordinate system problem. However, I want to have my code to be as independent as possible so I want to remove as much reliance on other classes as possible. These are the only methods that touch the Mouse input, and as far as I can tell none of them change anything so all is good here. Now for the Texture methods: public void draw() { if(!clicked || deactivatedImage == null) { activatedImage.bind(); glBegin(GL_QUADS); { DrawHelper.drawGLQuad(activatedImage, x, y, width, height); } glEnd(); } else { deactivatedImage.bind(); glBegin(GL_QUADS); { DrawHelper.drawGLQuad(deactivatedImage, x, y, width, height); } glEnd(); } } public static void drawGLQuad(Texture texture, float x, float y, float width, float height) { glTexCoord2f(x, y); glVertex2f(x, y); glTexCoord2f(x, y + texture.getHeight()); glVertex2f(x, y + height); glTexCoord2f(x + texture.getWidth(), y + texture.getHeight()); glVertex2f(x + width, y +height); glTexCoord2f(x + texture.getWidth(), y); glVertex2f(x + width, y); } I'll be honest, I do not have the faintest clue as to what is really happening in this method but I was able to put it together on my own and get it to work. my guess is that this is where the problem is. Thanks for any help!

  Read the article

• Drop shadow coordinate different from iPhone OS 3.2?

  - by Axel

  I'm trying to draw a custom view with a drop shadow. I'm having different results from iPhone OS 3.2. Has the coordinate system changed for CGContextSetShadowWithColor from 3.2? Here is the code I'm using: CGContextRef graphicContext = UIGraphicsGetCurrentContext(); CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB(); CGFloat values1[4] = { 0, 0, 0, 1}; CGColorRef blackColor = CGColorCreate (colorspace, values1); CGContextSetShadowWithColor(graphicContext, CGSizeMake(0, -1), 3, blackColor); CGColorRelease(blackColor); CGFloat values2[4] = { .5, .5, 1, 1}; CGColorRef fillColor = CGColorCreate (colorspace, values2); CGContextSetFillColorWithColor(graphicContext, fillColor); CGColorRelease(fillColor); CGContextFillRect(graphicContext,CGRectMake(40, 40, 100, 100)); Here is how it looks on 3.1 and from 3.2. All my views using drop shadow look different depending on the version of iPhone OS. Am I missing something?

  Read the article

• Getting x/y coordinate of a UITouch...

  - by Tarek

  HI, I have been trying to get the x/y coordinates from a touch on any iDevice. When getting the touch locations, everything looks ok if the touch is in the middle of the screen. But if I drag my finger to the bottom of the screen, I can only get a y coordinate of 1015. It should be getting to 1023. Same thing for dragging my finger to the top of the screen. I get -6. It should be 0. I have explicitly set the window and views to an origin of 0,0 and the width, height of the device's screen. Still nothing. I am really lost on what might be going on. Is something shifted? Am I not reading the x/y coordinates properly. Does something need to be transformed or converted? Any help would be much appreciated. T

  Read the article

• min max coordinate of cells , given cell length in c#

  - by Raj

  Please see attached picture to better understand my question i have a matrix of cells of [JXI] , cell is square in shape with length "a" my question is .. is there a way to use FOR loop to assign MIN,MAX coordinate to each cell taking origin (0,0) at one corner Thanks "freeimagehosting.net/uploads/3b09575180.jpg" i was trying following code but no success int a ; a = 1; for (int J=1; J<=5; J++) { for (int I = 1; I <= 5; I++) { double Xmin = ((I - 1)*a ); double Ymin = ((J - 1) * a); double Xmax = (I * a ); double Ymax = (J * a); } }

  Read the article

• Experience using IRC to coordinate software development?

  - by momeara

  I am part of a growing software project with at least 200 active developer in 10 locations. I would like to set up an on-line chat forum for developers because I think it would help to coordinate efforts. We have an email mailing list but I feel like some questions or announcements are too informal to send to everyone while mentioning it in a chat forum might be a useful community resource. I have never participated in a software project that used an on-line chat forum so I would like to hear about peoples experiences. I am particularly interested in technical issues: Use of IRC vs. alternative platforms; how to manage access, eg. for developers only, allowing users to participate; the value of requiring certain announcements to be made on the chat forum eg who is resolving broken builds etc. If I pitch the idea to the community I would like to have some good arguments why it would be a good idea and some prospective of its usefulness in other software projects.

  Read the article

• Determining if a coordinate is on a line

  - by TGCBraun

  I´m coding a little app that allows the user to draw multiple shapes and then remove or resize them. It´s working perfectly on rectangles and ovals, but I´m having issues with lines. Here´s a method that I wrote to find if the clicked spot on the screen is part of a specific line: public boolean containsLocation(int x, int y) { int m = (getY2() - getY()) / (getX2() - getX()); int b = getY() - (m * getX()); if (y == (m * x) + b) { return true; } return false; I´m using the famous y = mx + b formula and replacing y and x to find if the clicked spot is part of the line. The problem is when I click on the screen to remove the line, it only works if I click on the very fist coordinate (x,y) where the line starts. Nothing happens when I click anywhere else along the line. Can anyone shed a light on what I´m doing wrong? Thanks a lot.

  Read the article

< Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >