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

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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 ...
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1answer
682 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 ...
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2answers
350 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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83 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: ...
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1answer
514 views

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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94 views

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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28 views

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 ...
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1answer
197 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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1answer
299 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. ...
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1answer
254 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 ...
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244 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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131 views

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 ...
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213 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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205 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 ...
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1answer
483 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 ...
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2answers
802 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 ...
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1answer
129 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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1answer
247 views

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 ...
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115 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 ...
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247 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 ...
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1answer
64 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 ...
2
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1answer
129 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 ...
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1answer
1k 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 ...
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1answer
306 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() { ...
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1answer
5k 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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1answer
172 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; ...
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75 views

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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2answers
296 views

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) ...
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1answer
683 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 ...
2
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1answer
391 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) ...
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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 ...
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2answers
224 views

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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2answers
1k views

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 ...
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472 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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1answer
150 views

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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1answer
210 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 ...
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67 views

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 ...
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1answer
693 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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1answer
63 views

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, ...
2
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1answer
740 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). ...
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621 views

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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3answers
600 views

Transforming a primitive tetrahedron into a primitive icosahedron?

I've created a tetrahedron by creating a BoundingBox and building the faces of the tetrahedron within the bounding box as follows (see image as well): VertexPositionNormalTexture[] vertices = new ...
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1answer
255 views

Rotate/Translate object in local space

I am just trying to create a movementcontroller class for game entities. These class should transform the entity affected by the mouse and keyboard input. I am able to calculate the changed rotation ...
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1answer
334 views

Apply bone tranforms when importing FBX in XNA

Preconditions: I have some models, that does only contain some meshes and one texture. There is no animation within the model. An example: a model of a table. I want to draw the Model with a custom ...
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1answer
590 views

How can I attach a model to the bone of another model?

I am trying to attach one animated model to one of the bones of another animated model in an XNA game. I've found a few questions/forum posts/articles online which explain how to attach a weapon ...
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173 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 ...
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132 views

coordinate transformation

I have two coordinate systems, like so How can I transform a point on the one of the coordinate system to other ? Pxyz = M . Px'y'z' what is M ?
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973 views

How can I reflect a point with respect to the plane?

How can I reflect a point with respect to a plane? Example: I have three points (0,0,2), (4,0,0) and (0,8,0). And I have a point (x,y,z). From these, I want derive a composite transformation matrix. ...
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2answers
363 views

3d vertex translated onto 2d viewport

I have a spherical world defined by simple trigonometric functions to create triangles that are relatively similar in size and shape throughout. What I want to be able to do is use mouse input to ...