# Tagged Questions

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

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### 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 ...
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### How to do geometric projection shadows?

I have decided that since my game world is mostly flat I don't need better shadows than geometric projections - at least for now. The only problem is I don't even know how to do those properly - that ...
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### Transformation matrix that maps a window

I'm currently learning OpenGL at uni, and they give us questions to help us learn (these are not worth anything), however I'm stuck on this one question and would have to travel over an hour and a ...
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### Translate along local axis

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 ...
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### In Maya how do I convert trans, rot, scale data to a 4 x 4 transformation matrix?

I have been given the following Maya camera data: trans X: 1.542 trans y: 3.319 trans z: -1.821 rot X: 117.882 rot Y: 2.189 rot Z: 154.074 scale X: 1 scale Y: 1 scale Z: 1 What is the ...
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### Strange behavior with transformation matrix

I'm fairly new to transformation matrices. I'm using them to translate and rotate nodes and their child nodes. The following code works when applied once, but shows strange behavior when applied many ...
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### LibGDX viewport touch coordinates transformation

I've been trying to get LibGDX's viewport and camera unproject() to work and so far none of the tutorials/answers I've found have worked for me. I have a game window of 840x480 units with FitViewport....
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### Unity C# Object Scaling when parenting by script

How do I make it so an object doesn't scale with another object that I parented it with by script? If anyone knows how to get around this I would really appreciate it. This is the part of the script ...
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### What's the implication of right-handedness when building camera to world matrix?

I found these slides which go through the viewing transform in what I think is a easy way. However, I have hard time understanding two thigs: What would be the implication of using a right-hand ...
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### Separate rotation transform from parent

I have a hierarchy like this Body - Head - Arms Currently this works fine in that the Body's transformation is reacting as it should. Being children, the Head and Arms match the Body's ...
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### Rendering curved text in AndEngine

I'm trying to implement a small game using AndEngine and I have a question about the Text. More specifically, I'm wondering if it is possible to deform the text so that you can have a "curved" text or ...
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### How to project spherical coordinates to canvas

I have objects with coordinates in a spherical coordinate system (altitude alt and azmiuth az). I want to project those to my canvas with a given size (128 x 128 pixels²) and resolution (about 6 px/°)....
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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),...
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### Bullet Physic: Transform body after adding

I would like to transform a rigidbody after adding it to the btDiscreteDynamicsWorld. When I use the CF_KINEMATIC_OBJECT flag I am able to transform it but it's static (no collision response/gravity). ...
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### OpenGL: Move camera regardless of rotation

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 ...
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### Making a cube slowly rotate 180 degress one time on a mouseclick

I am new to C# and new to Unity. I made a script that can turn a cube slowly one time after a mouse click but I feel like its probably wrong for using FixedUpdate. Is this OK or is there a better way? ...
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### Why does the projection matrix transform object points into a unit cube in computer graphics?

This semester I both took a computer vision and a computer graphics seminar. But only now before the exams I realize that there seems to be a fundamental difference between projection in both topics. ...
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### Distort a quad with a World Matrix

Is it possible to distort a quad multiplying its vertices by a specific world matrix? See the picture to understand what kind of distortion I need: Please note, that the quad is in 3d space and I ...
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### Generating transformation matrix for 2D camera with pan/zoom/rotate

Question How do you implement a camera with pan/zoom/rotation for a 2d game? Is it acceptable to multiply together a series of transformation matrixes to generate a final transformation matrix that ...
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### 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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### 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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### 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 child elements position into a world position

I'm making a 2d space game in Javascript with canvas. In this game there's a bunch of spaceships, positioned in world space, with turrets, positioned relative to their parent ships. These objects also ...
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### Ball's velocity vector, reflect against a point

I need to calculate the new velocity vector when the ball collides with one of the paddle's corners. Let d be the velocity vector of the ball, r the target velocity vector and n the surface normal ...
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### Proper normal vector transformations in normal mapping

Hello! This question is about transforming normal vectors from normal maps properly. I have tried methods from over five sources, still can't get it to work, and I'm really desperate. Included are ...
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### How do I create a view matrix directly from a quaternion and a position vector?

Given a quaternionic camera such that: typedef struct { vector3 upReference; vector3 rightReference; vector3 forwardReference; vector3 position; quaternion orientation; ...
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### How do I animate Unity GUIComponents?

I want to transform my GUIWindow from the bottom of the screen to the middle whenever the user presses a button. How can I do this?
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### 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) ...
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### How to work with edge Texture [duplicate]

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 ...
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### importing animations in Blender, weird rotations/locations

This is for the Blender 2.6 API. There are two problems: 1. When I import a single animation frame from my animation file to Blender, all bones look fine. But when I import multiple (all of the ...
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### What is a good practice for deciding when to use transforms instead of applying force?

I was making several games. I don't understand when I should use addTorque instead of rotate. AddForce instead of position The latest game was a pinball game. I wasn't sure the best way to active ...
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### Adjust postion only in X axis

I have two game objects named A and B, just as follows: I want to move object B to this virtual line without any rotation so that the destination is B' . What I have are transformation of object A ...
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### Translating Objects in Worldspace

Given the worldspace coordinates of a collection of arbitrarily positioned objects, how do I translate them while preserving their relative placement? For instance, I have a table and a few bowls that ...
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### Deformation of Sphere using Transformations

I have a graphic related question. I need to have a transformation matrix that I have no idea about what it is. The problem is to create right image from the right sphere. I created those images in ...
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### Should I store local forward/right/up vector or calculate when necessary?

I'm working on an object picking and translation/rotation/scale gizmos system in my engine where you select objects and perform transformations on them in a 3d editor-like fashion (e.g. Blender) In ...
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### What is more efficient: Using matrix translation to move a character, or using a vector/scalar?

In 2D or 3D, matrix transformations are used for rotation, scaling, and sheering. However, when it comes to movement, should I go out of my way to use and implement scalar/vector movement, or just ...
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### Terminology for the way Transformation Matrix Data is treated

I recently asked a question at math stack exchange and realize a similar questions is more suited for this forum, but the original is here: http://math.stackexchange.com/questions/1526601/terminology-...
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### Applying Transformation Matrices to VBOs in OpenGL

So I've recently tried to add Vertex Buffer Object Matrix transformation to an OpenGL engine I'm working on. I could go about this by applying the matrix to a copy of each vertex individually, but ...
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### Transformation by right vector using TransformPoint return an identical position

I think the following code should work. I'm trying to set the position of a GameObject where the pointer currently is, I mean, where the player is looking currently: public void SetTransform (...
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### How to compute the forward, up and right vectors from a single quaternion?

Given a quaternion float x, y, z, w; How does one the forward, up and right vector from a single quaternion? vec3 up; vec3 forward; vec3 right; quat_get_all_axis(&quat, &up, &forward, ...
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### Camera world matrix to view matrix

I've been working on a game engine and I model every object in my scene graph as an "entity" this includes my camera. My camera therefore has a position and rotation in world space and at the moment ...
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### How can I make EaselJS' skew behave like canvas'?

The skew property of a bitmap in EaselJS (given as angle) rotates the image such that it also flattens. I'd like to skew it without "squashing" it, as canvas does. JSFiddles, to demonstrate: Canvas ...
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### How can I make an attached gameobject behave correctly on character flip?

I have a character that on start-up is equipped with another gameobject/prefab as a weapon, attaching it to a hand. void Start() { handFront = transform.Find ("root/Hip/BodyBone/OverArmFrontBone/...
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### Unity3D Drag Object with Mouse Gives Invalid Position

I am trying to implement a simple script to drag a GameObject with the mouse in Unity. However, when the position of the object is updated with the following script, I get an error saying: transform....
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### 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 (...
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### 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() { ...
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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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### 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 ...