# Tagged Questions

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35k views

### Why do we move the world instead of the camera?

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: OpenGL View matrix ...
5k views

### Why is Y up in many Games?

I learned at school that the z-axis is up. It is the same in modeling software like Blender. However in many games the y-axis is up. What is reason?
481 views

### What would a “2nd person” viewpoint consist of?

Traditional narratives have one of three viewpoints: First person (I fought the monster) Second person (You fought the monster) Third person (He/She/It fought the monster) First and Third person ...
2k views

### How to Simulate Height in a Tiled Top-Down Game

How can I simulate height in a top-down tiled 2D game? One way I thought was to make tiles which are supposed to be higher brighter, but I was wondering if there was a standard or better ...
630 views

### How can I calculate where my camera can be to avoid showing something outside a region?

I have a landscape model, which goes from the coordinate -45, -45 to 90, 90. The edge of the model just cuts off and i would like to somehow stop the screen from ever passing these points. Basically ...
842 views

### How can I achieve a zoom-like camera effect?

I have a top down 3D camera: view = Matrix.CreateLookAt(new Vector3(0,0,20), Vector3.Zero, Vector3.Up); Now I want to achieve the effect like when I zoom in the scene and only show a section at the ...
69 views

### How do I align the cube in which shadows are computed with the view frustrum? (“View Space aligned frustum”)

Short and concise: Given 8 world space positions that form a cube of arbitrary size, position and orientation and given an arbitrary light direction. How do I compute the View and Projection matrix ...
2k views

### Can a 4x4 matrix describe a camera's perspective?

I'm working with a closed-source 3D engine, and it only allows you to set the view projection via a 4x4 matrix. Can this matrix describe the camera's translation, rotation & perspective? I turned ...
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?
155 views

### Unity Change Sceneview to camera view

On selecting camera, I get the camera preview. In Unity, while editing the scene, I wish to switch in such a perspective view that is exactly visible by the main camera. Is there a short cut to ...
296 views

### How to set borders in Rubik's cube using opengl GLSurfaceView

I'm developing a Rubik's cube game like seen in the picture. But I'm facing problems to set the cube face color with black border. public void setupSides() { int i, j, k; // Paint back blue i = 0; ...
37 views

### How can I communicate a Joystick with a SurfaceView?

I have two classes: JoystickView (Extends View). GameView (Extends SurfaceView): It will be updated by a Thread that call the onDraw Method. Now, if I retrieve a direction by OnTouchEvent inside ...
133 views

### Model View Controller linking dynamic model to view

I currently an implementing a game roughly using a model-view-controller setup. A single game controller instantiates a model and view. The model and view then instantiate child models and views, ...
93 views

### Problem to change window view dragging the mouse

I'm having a bad time trying to change the window view by dragging the mouse. I can precisely do that with the method: void PlayScreen::MenuView(sf::RenderWindow& window) { while (sf::Mouse::...
204 views

### XNA: How do I match Spritebatch View/Projection Matrices with BasicEffect Matrices?

I'm rendering a bunch of 2D content using SpriteBatches to a default XNA viewport. A simple 2D camera is used to move around the scene, which generates a transformation matrix passed to each ...
330 views

So I've been scouring the interwebs for a couple of days with regards to how to implement sprite masking in XNA 4 and C#. Coming from a pet project I did in Flash, this was pretty easy as masks are ...
379 views

### Camera - View matrix in Android + openGLES 2

I am trying to use the touch screen on the tablet to control my camera movements and generate the view matrix accordingly. I get the x and y coordinates of the screen and after doing some sanity ...
817 views

### Top Down bounds of vision

Obviously in a first person view point the player sees only what's in front of them (with the exception of radars and rearview mirrors, etc). My game has a top down perspective, but I still want to ...
301 views

### Matrix camera, movement concept

Someone told me that the movement concept in my 2D game is bad. When left or right arrow is pressed I'm scrolling the background which makes you feel that player avatar is moving (the avatar's X-...
5k views

### Show view over existing view in same activity

I am newbie Android developer, and I am starting out with a simple Sudoku game. The problem I am facing right now is that I have my game showing on a dedicated Activity, which is displaying a custom ...
511 views

### Strange 3D game engine camera with X,Y,Zoom instead of X,Y,Z

I'm using a 3D game engine, that uses a 4x4 matrix to modify the camera projection, in this format: r r r x r r r y r r r z - - - zoom Strangely though, the camera does not respond to the Z ...
613 views

### HLSL What you get when you subtract world position from InvertViewProjection.Translation?

In one of NVIDIA's Vertex shaders (the metal one) I found the following code: // transform object normals, tangents, & binormals to world-space: float4x4 WorldITXf : WorldInverseTranspose < ...
3k views

### How to switch between views in android?

I've tried several methods to switch between two views in my program. I've tried creating a new thread then have the view run for 5 seconds before creating intent to start my main activity. This is ...
613 views

### How to update UI after changing text in a view

After applying a text change to a scrolling view, how do you get the new height of the text, resize other UI elements around the changed text length, etc? Many have posted this question. Some have ...
184 views

### projection / view matrix: the object is bigger than it should and depth does not affect vertices [closed]

I'm currently trying to write a C 3D software rendering engine from scratch just for fun and to have an insight on what OpenGL does behind the scene and what 90's programmers had to do on DOS. I have ...
68 views

### What is the correct way to seperate (react) view from state?

I would like to know the correct implementation to declare game logic and view logic: I see 3 ways of implementing this: 1.Storing (eg writing preprocessing to store the change to a property) ...
426 views

### UIView with IrrlichtScene - iOS

i have a UIViewController in a Storyboard and want to draw a IrrlichtScene in this View Controller. My Code: WWSViewController.h #import <UIKit/UIKit.h> @interface WWSViewController : ...
2k views

### Android-Handling screen clicks for dynamically moving objects in a view

I have a kind of broad question to ask but I have to start some where so.....What is the best way to handle onscreen clicks for moving objects being drawn on a canvas in a view. Im registering the ...
41 views

### Creating SurfaceView cause short screen blink

When I create SurfaceView for first time since app launch, the app screen blinks black for small time (about 1/4 second). It blinks over UI, so its really visible and doesn't look nice at all. I've ...
18k views

### onTouchEvent only working for one view within activity

I have a parent Activity which contains 2 views. One view is a custom view class, where I am overriding the onDraw method. This view contains an onTouchEvent function, which is checking for user ...
78 views

### Unity why do all gameobjects not dissapear from view when I switch cameras?

I am having trouble with camera switching. I have two cameras: "Camera1" and "Camera2". A "button script" attached to Camera1 allows a switch to Camera2. It also positions the cameras. There is a ...
73 views

### Everything black except where there's a light

I have a camera in my scene with a map created at runtime: As you can see everything can be seen. Now I want the map to be invisible (black as the background) except where there are lights. How can ...
116 views

### Scaling world - projection, view or separate matrix?

I am currently writing a simple 3D space visualisation program. Things get loaded into it from a simple XML file, which contains positions and sizes of objects in space, so you can put basically any ...
1k views

### View Matrix from Camera in Unity Script

I am looking to get a Camera component's "view" matrix in a script. I see that I can get the projection matrix using Camera.projectionMatrix, but I don't see a Camera.viewMatrix property... I want ...
74 views

### Put layout over Surfaceview

I have this problem: I'm trying to create new RelativeLayout over whole screen - which also contains SurfaceView in the middle - and display some things on this RelativeLayout (in my case Imageview ...
47 views

### How to make the minimap inactive?

I have created a minimap for my top-down Shooter and it is showed on the top-left corner of the window. The problem is that if I press anywhere upon the minimap, its like pressing somewhere on the ...
283 views

### How do I center the view around specific coordinates in SFML

I want to use sf::View in SFML in order to change the position of the view, such that the player sprite is always in the center of the screen. Thus I want to write a function which allows me to input ...
334 views

### Fixed background on a SurfaceView

I'm currently working on a top-down twin-stick shooter for Android. I've got my player moving around and shooting, but I'm looking to add a large Bitmap background which is larger than the device ...
2k views

### Implement Camera (former: CCCamera) v2 in cocos2d-x v3.3

we want to port camera code from cocos2d-x version 2 to version 3.3 with the goal to imitate the behaviour of a CCCamera in cocos2d-x version 2 exactly. You can assume that values for "eye" and "up" ...
583 views

### Y Axis inverted on vertex output

I've got my project running and somehow it seems my vertex y components are inverted. 10 in the positive on Y goes down and 10 negative on the Y axis goes up. I can't find anything with the ...