# Tagged Questions

Transformation in game development is usually refers to linear algebra operations on points, vectors and matrices.

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### Precision loss when transforming from cartesian to isometric

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 ...
410 views

### OpenGL camera translate and rotate on cameras local axis

How can I make rotation and translation on a local camera axis in OpenGL? I want to make camera like "aeroplane" camera with a pitch yaw and roll. I want to have good explanation on everything! Can ...
2k views

### The View-Matrix and Alternative Calculations

I'm working on a radiosity processor in DirectX 9. The process requires that the camera be placed at the center of a mesh face and a 'screenshot' be taken facing 5 different directions...forward...up.....
558 views

### Split up a screen into regions

My task: I want to split up a screen into 3 regions for buffs-bar (with picked items), score-info and a game-map. It doesn't matter are regions intersect with each other or not. For example: I have ...
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### Picking problem with rotated view matrix

I have picking code that works, if my view matrix has no rotation (only translation). Now If I rotate my camera, picking goes to hell. I cant find whats wrong My code: /*----------------------------...
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### Rotate 2D Isometric World

Games like RollerCoaster Tycoon allow you to rotate the view at 90 degree intervals. I'm wondering how I could apply this to a game I'm making. I'm using MonoGame... but I'm wondering more if anyone ...
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### Last Matrix operation ignored?

I have 2 methods, one to rotate my Quad and one to flip it (using scaleM), they are as follows: (Note, all values in these methods have been properly defined). If I call just one, they work as ...
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### Correct way to use a GameObject.Find method in Unity C#

I have been following along with a Lynda.com video course to familiarize with Unity. I am currently attempting to grab a reference to a scene's First Person Controller's transform as follows: ...
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### Constrain parent node transform to child bounds

If I have some node rendering tree set up, where a node basically has a draw method to render things, and a transform, represented as a 3x3 matrix, with scale and translation. Now, I would like to ...
337 views

### How can shears/reflections/enlargements be represented by 4x4 matrices? [closed]

I understand that 4x4 matrices can represent transformations on a 3d point (represented as x, y, z, w) Eg, a translation is [1 0 0 0] [0 1 0 0] [0 0 1 0] [x y z 1] where x, y and z are the amount ...
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### How do I make my camera follow a Box2D object?

I'm implementing a camera in my game. It worked 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. ...
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### Need transform matrix to translate the center of the view to a custom position within the target texture

My problem is as follows: I want to use a single render target texture for drawing 16 viewports where I want to display the 16 different combinations of the marching squares algorithm with my 3D ...
308 views

### World to Pixel Transformation

My objects have a location in world coordinates (basically 1.0f is a meter). If I simply draw my objects using their world coordinates, each meter will correspond to a pixel. Obviously that's not what ...
615 views

### Shear transformation in the projection matrix?

I am trying to understand what the shear transformation (l+r/r-l & b+t/t-b) is actually doing in the projection matrix? The only thing I got till now is headache :) Can you please help?
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### Common way to store model transformations

I ask myself what's the best way to store the transformations in a model class. What I came up with is to store the translation and scaling in a Vector3 and the rotation in a Matrix4. On each update (...
391 views

### Sfml: Sprite scale transformation animation

Is there any way to animate a transformation on sf::Sprite like setScale or setPosition? ie: sprite.setScale(0.5f,0.5f);. I want the transition between normal and half scale be smooth. Thanks!
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### How to calculate the Screen Position of a bounding sphere/box?

Synopsis: What I have is an object rendered on the screen. I need to calculate the top-left / bottom-right of it's location on the screen in Screen Coordinates. Explanation: The object is ...
821 views

### Android OpenGLES 2 ray picking, resulting coordinate jumpy in certain spots?

I am trying to implement object picking based on touch coordinates via an intersecting ray test. I am having trouble finding information on converting the touch coordinates to the coordinate system ...
676 views

### Move parent according to child axis in Unity?

Can I ask my parent to move according to the child axis? This means if I turn right, then right again, the parent has to be at 180° from its original position, and not only at 90° (because "Right" ...
2k views

### Realtime fisheye to cubic or spherical panorama transformations with OpenGL or pixelshaders

I'd like to transform a sequence of circular fisheye-images to cubic or spherical panorama images to be used in a panorama-viewer based on OpenGL. The viewer-part is nemas problemas but the transform ...
147 views

### XNA Camera Positioning All Wrong

I've been working in 3DSMax for years now and decided to give XNA 4.0 a try. I've got the majority of it working, however the camera is being a pain to me and I can't discern what's gone wrong. I ...
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### Translating Viewmatrix is inverted, why?

So I've defined a Projectionmatrix, Viewmatrix and a Modelmatrix using OpenGL (LWJGL). But when I translate my Viewmatrix to +X it moves my object to the right (hence my camera is moving to the left),...
177 views

### Transform translation relative to world space

What is common algorithm for translating a transform matrix relative to world space axis? E.g. Matrix M is representing some local space. When I want to translate M relative to it's own local axis, I ...
906 views

### Transformations are not correct using GLM and OpenGL

The aim of my program is to render a simple colored triangle in rotation. The rotations are correct if all Z values of my vertices are equals to 0.0f. If one of these values are different of 0.0f the ...
67 views

### changing coordinate system

I'm currently trying to transform a system by scaling it on x and y axis and have some uncertainty. I have the general concept that scaling works as such: My original box has corners at (0, 0) and (...
151 views

### transformations of matrices

I'm in the process of reading up on 3d matrices and trying to following this powerpoint and had a few questions as to how to exactly determine the type of transformation from a matrix. If I have a ...
2k views

### Interpolating a player between two 2D points?

I would like a player to be able to move in a direction smoothly, whilst sticking to a fixed grid. Much like in Pokemon, how the player can move, but when the key is pressed and released quickly, they ...
369 views

### Canvas isometric translations to integer coordinates

I'm creating a canvas based game with an isometric playing board. I use the following transformations to get my square tiles to render on the screen: 'applyViewportTransformation' : function() { ...
7k views

### Rotate object to always face camera

I'm trying to make a TextMesh appear when ever an enemy prefab is hit. I currently have this functionality working. However, the text doesn't face the direction the players camera is looking. At the ...
13k views

### How to extract euler angles from transformation matrix?

I have a simple realisation of entity/component game engine. Transform component have methods to set local position, local rotation, global position and global rotation. If transform is being set new ...
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### Proper approach to handle transformation matrix and extract its components

Basically I have a Transformation component object with following structure(pseudo): TransformComponent{ Vec3 position; Vec3 rotation; //in euler angles Vec3 scale; Mat4 worldMatrix; //...
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### How to change Vectors due to change in it's dependent Base Vector?

PLOT : I have been developing a game where the player falls down on Y axis and the camera is a Top-Down view camera. The camera, player (main character in the game) movements etc. have all been ...
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### Calculating transform of arrow model pointing at some point in 3D space

I'm working on a 3D flight game and I'd like to implement a simple "navigation arrow" pointing at the next waypoint in world which the player has to fly to. I have position of both airplane (=camera) ...
998 views

### Rotation of Rectangle along Y-axis transformed to parallelogram

After the rotation of a rectangular view along the Y-axis, about its center, transformed into parallelogram, how do I get the rotated parallelogram coordinates? By Y-axis, I mean perpendicular to the ...
420 views

### How can I create a 2D camera with upscaling and translation?

I've computed a Viewport that is fair in size (a proper aspect ratio to the given device) and then I calculate my ScaleMatrix like so: scaleMatrix = Matrix.CreateScale( (float) ...
1k views

### How rotate a 3D cube at its center XNA?

I try to rotate a 3D cube on itself from its center, not the edge. Here is my code used. public rotatemyCube() { ... Matrix newTransform = Matrix.CreateScale(scale) * Matrix.CreateRotationY(...
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### Render rotated rectangle inside other rectangle bounds using Libgdx

I have this code to generate a red rectangle inside a grey rectangle: new Rectangle(grey_rectangle_position_x, Game.SCREEN_HEIGHT/2-Rectangle.height/2,0); This code makes the following: Now, I ...
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### OpenGL: Transformations

I'm not sure if I correctly understand 3D transformations in OpenGL. Let's assume I'm using the typical matrix stack. It seems like you move the world X units over, drop in a bag of verts (a mesh) ...
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### How can you extract orientation from a transformation matrix?

I have a 4x4 transformation matrix M, and I want to find out the shape of a sphere when transformed by M. (Sphere is at the origin and has radius 1.) I know I can find the center by just multiplying ...
670 views

### 2D Matrix Transformation (with a Player and Ground)

I have a simple game that I'm trying to do for learning purposes, but Matrices are a bit hard, especially in DirectX. I currently have a tilesystem that renders tiles at the screen and a character ...
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### Pygame's rotation methods have crippling issues, but is it me or Python's pygame?

http://www.youtube.com/watch?v=lNJFxvR6ex8&feature=youtu.be On rotate and rotozoom, can't find fixes on these on the internet, anywhere. Basically, the video is showing 4 things in this order: 1. ...
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### Calibration of a 6 DOF tracking device

Setting: In our facility we have a 3D laboratory with 3 large displays (two edge-to-edge on orthogonal walls, one on the ground, also edge-to-edge). Its primary use-case is exploring 3D virtual ...
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### Skeletal Animation with UV seams

I have a UV-mapped model that I am about to animate and load into my game. Like most unwrapped models, I have several UV seams. In order to render the model correctly, I split each vertex along the ...
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### SimpleOpenNI: Check if user hand is in specific area on image

Concerning our Microsoft Kinect project, we need some help. We control a robot with our movements tracked by the Kinect sensor. We display the depth image of the Kinect sensor on our screen, so we ...
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### Transform a Screen Delta

I have a delta in screen coordinates that I want to transform to a 3d delta in world space. The delta is in this case a movement across the (x,y) coordinates in screen space on the near projection ...
2k views

### Scaling along an arbitrary axis (Dealing with non-uniform scale)

I'm trying to build my own little engine to get more familiar with the concepts of 3D programming. I have a transform class that on each frame it creates a Scaling Matrix (S), a Rotation Matrix from ...
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### How to transform a subset of a vertex in a vertex buffer?

float linePos[6]={0.0f,5.0f,0.0f,0.0f,30.0f,0.0f}; ... glGenBuffers(1, &buffer); glBindBuffer(GL_ARRAY_BUFFER, buffer); glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*2, linePos, ...
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### How is the gimbal locked problem solved using accumulative matrix transformations

I am reading the online "Learning Modern 3D Graphics Programming" book by Jason L. McKesson As of now, I am up to the gimbal lock problem and how to solve it using quaternions. However right here, ...