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

learn more… | top users | synonyms (1)

2
votes
1answer
1k views

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). ...
2
votes
1answer
789 views

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 ...
2
votes
1answer
87 views

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. ...
2
votes
1answer
76 views

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 ...
2
votes
1answer
1k views

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 ...
2
votes
2answers
435 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 ...
2
votes
1answer
365 views

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. ...
2
votes
1answer
1k 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 ...
2
votes
1answer
391 views

Transform 3D vectors between coordinate systems

I've got 6 points in 3D space: A,B,C,D,E,F, that represent 4 vectors. AB is perpendicular to AC and DE is perpendicular to DF. I need to find a transformation matrix M, that transforms AB to DE and ...
2
votes
2answers
332 views

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 ...
2
votes
1answer
91 views

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 ...
2
votes
1answer
409 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) ...
2
votes
0answers
81 views

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 ...
1
vote
3answers
403 views

Inverting matrix then decomposing gives different quaternion than decomposing then inverting the quat

I'm getting different signs when I convert a matrix to quaternion and invert that, versus when I invert a matrix and then get the quaternion from it: Quaternion a = Quaternion.Invert(getRotation(m)); ...
1
vote
1answer
17k views

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: ...
1
vote
3answers
2k views

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 ...
1
vote
2answers
52 views

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 ...
1
vote
1answer
13k views

How can I translate a game object towards a position?

I am instantiating my game objects (spheres) through scripts. I want my spheres to move from one location to another. but I don't know how to do this. Update is called once per frame. Is that what I ...
1
vote
1answer
189 views

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 ...
1
vote
1answer
70 views

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, ...
1
vote
1answer
53 views

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 ...
1
vote
2answers
422 views

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 ...
1
vote
1answer
158 views

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 ...
1
vote
1answer
3k views

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: ...
1
vote
1answer
66 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 ...
1
vote
1answer
345 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() { ...
1
vote
2answers
2k views

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 ...
1
vote
1answer
230 views

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 ...
1
vote
1answer
1k views

Translating local to global coordinates in ARToolkit / OpenGL

Ok, so I've tried reading over the other questions and something's just not clicking for me. I am working on an augmented reality application using ARToolkit, however it should just be straight ...
1
vote
1answer
23 views

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 ...
1
vote
1answer
37 views

Is the statement in Scratchapixel about transforming points correct?

I am reading this lesson from scratchapixel. To my understanding (and the example given in the same website) M is the matrix that transforms from local to world. Giong through the paragraph before ...
1
vote
2answers
113 views

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? ...
1
vote
1answer
137 views

Problem with 2D matrix transform og shapes

I have set myself onto the task of creating a class BaseObject, which represents a graphics object with an associated shape as the member variable shape, which is a pointer an object Polygon. I'll ...
1
vote
1answer
182 views

How to constrain axis-angle rotation?

I have a problem where I'm performing an axis-angle rotation and am trying to constrain my rotations. Specifically I have a skeleton (model/mesh with rig, transforms are hierarchy parented to pelvis ...
1
vote
1answer
28 views

Error in plane transformation

I have a bunch of coplanar points, who sit on plane P. I want to translate the plane to Q with the points upon. Here is what I do: I take three points from P, say a, b, c. Their centroid is denoted ...
1
vote
1answer
79 views

How do I combine matrix transformation with non-uniform screen scaling in Flash?

I'm using a Flash transformation matrix for affine transformation. I have a rectangular image being rotated and scaled (in 2D). There are two sets of scaling variables, ScreenScaleX and ScreenScaleY, ...
1
vote
1answer
79 views

Matrix transformation

I have to find components of a matrix for 3D transformation. I have a first system in which transformations are made by multiplying: M1 = Scale x Rotation x Translation. I want to have the same ...
1
vote
1answer
63 views

How can I transform a Point2f with a matrix on Android?

I'm developing for Android and I'm using the android.renderscript.Matrix3f class to do some calculations. What I need to do now is to now is to do something like mat.tranform(pointIn, pointOut); So ...
1
vote
2answers
125 views

Do I need to store a generic rotation point/radius for rotating around a point other than the origin for object transforms?

I'm having trouble implementing a non-origin point rotation. I have a class Transform that stores each component separately in three 3D vectors for position, scale, and rotation. This is fine for ...
1
vote
1answer
295 views

How to rotate vertices of 2D shape using a transform matrix?

I am making a top-down 2D game and am currently working on implementing improved collision using SAT. I programmed a Shape class with a Vector2 center that is its position in world space. On top of ...
1
vote
1answer
187 views

How to make child transforms honor parent origin

I'm working on a 2D transform system that has the following requirements: Transforms can have children Transforms have anchor points/origins that offset them Children should honor the parent's ...
1
vote
1answer
89 views

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: ...
1
vote
1answer
264 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 ...
1
vote
1answer
252 views

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 ...
1
vote
1answer
196 views

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; ...
1
vote
1answer
543 views

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. ...
1
vote
1answer
239 views

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 ...
1
vote
1answer
174 views

Rotate an image in a scaled context

Here is my working piece of code to rotate an image toward a point (in my case, the mouse cursor). float dx = newx - ploc.x; float dy = newy - ploc.y; float angle = (float) ...
1
vote
1answer
163 views

Orthogonal projection and world transform

I'm reading about projection matrix. Needs of perspective projection is obvious, but I'm not sure about orthogonal projection. Because orthogonal projection effect looks possible with only world ...
1
vote
1answer
540 views

Transform 3d viewport vector to 2d vector

I am playing around with 3d transformations and came along an issue. I have a 3d vector already within the viewport and need to transform it to a 2d vector. (let's say my screen is 10x10) Does that ...