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10
votes
1answer
2k views

Screen space to world space

I am writing a 2D game where my game world has x axis running left to right, y axis running top to bottom, and z axis out of the screen: Whilst my game world is top-down, the game is rendered on a ...
0
votes
3answers
287 views

Project rendering onto a polygon in the scene

I have a function that renders a simple OpenGL scene. I want to display this scene on a polygon within another scene, without the function having to know about it. For example, to display the scene on ...
6
votes
3answers
1k views

Arbitrary projection matrix from 6 arbitrary frustum planes

A projection matrix represent a tranformation from the camera view space to the rendering system clip space. In other words, it defines the transormation between a 6-sided frustum to the clip cube. ...
3
votes
1answer
3k views

How do I create a decal system?

I'm currently given the task to design & create a simple decal-system in C++/DirectX. Does anybody know a great tutorial, article or paper to start with? (Especially the part about 2D-texture to ...
3
votes
1answer
526 views

Does the projection matrix flip winding order in right handed systems?

I am using a right handed coordinate system for my world coordinates (so, positive x goes right, y is up, and z is towards you). However, after projection and the w divide, nomalised device ...
4
votes
1answer
852 views

Perspective projection with 90 degrees between X-Y axis?

I'm trying to create a game that mimics Tibia's projection style: , As you can see, a 3d point is mapped to 2d like this: So I've downloaded Three.JS and a lib to create a Orthographic Camera. But ...
5
votes
2answers
1k views

What's a pre-multiplied 4x4 matrix?

I'm using a 3d game engine, that uses a 4x4 matrix to modify the camera projection. The matrix is in the regular 4x4 format: r r r x r r r y r r r z - - - zoom The description for the ...
3
votes
1answer
476 views

How to calculate FOV with four-walled tiles?

I'm working on a 2D tile-based game. I'm trying to calculate FOV and I've implemented walls so they don't take up an entire tile. Instead, they just take up a side of each tile. Similar to: class ...
5
votes
3answers
536 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 ...
2
votes
1answer
371 views

Shader issues when creating projection using CreateOrthographicOffCenter instead of CreateOrthographic

Pre. Having these matrix transformations: var scale = Matrix.CreateScale(50f); var eye = new Vector3(0, 0, 10.0f); var view = Matrix.CreateLookAt(eye, Vector3.Zero, Vector3.Up); var projection = ...
3
votes
1answer
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 ...
2
votes
1answer
752 views

How to create projection/view matrix for hole in the monitor effect

Lets say I have my XNA app window that is sized at 640 x 480 pixels. Now lets say I have a cube model with its poly's facing in to make a room. This cube is sized 640 units wide by 480 units high by ...
2
votes
2answers
1k views

How should I calculate world and projection matrices in this scenario?

I'm trying to understand transformation matrices. Suppose I use the camera from this StackOverflow answer, this is how my view matrix would look: Matrix.Identity * ...
14
votes
3answers
2k views

Faking isometric graphics in a 2D space game

First off, I know exactly what my drawing problem is, and I have various ideas on how to approach solving it. I am here to figure out how to adjust which frame is drawn so that the isometric ...
8
votes
1answer
721 views

Projected trajectory of a vehicle?

In the game I am developing, I have to calculate if my vehicle (1) which in the example is travelling north with a speed V, can reach its target (2). The example depict the problem from atop: There ...
8
votes
3answers
3k views

What is the name of perspective of Age of Empires II?

One would describe Age of Empires 1's "perspective" as a 2D sprite game (screenshot). Below is a screenshot of Age of Empires II. How would you describe the "perspective"? Is it also a 2D sprite ...
8
votes
1answer
657 views

Downprojecting an imaginary 4D mesh to the screen

As a mental exercise, I'm trying to imagine projecting an arbitrary 4D mesh onto the screen (2D). I'm guessing a single 4D triangle would still consist of only 3 points, however each of those 3 ...
14
votes
5answers
7k views

Do I need the 'w' component in my Vector class?

Assume you're writing matrix code that handles rotation, translation etc for 3d space. Now the transformation matrices have to be 4x4 to fit the translation component in. However, you don't actually ...
5
votes
2answers
492 views

Is a dynamic enviroment map using pincushion curvilinear perspective projection possible?

I'm wondering if it is possible to generate a dynamic spherical environment map using a single frame render using a pincushion curvilinear perspective projection matrix (phew, that's a mouthful)? ...
3
votes
2answers
659 views

XNA - Non perspective projection?

For a section of my game, instead of having a perspective projection, i would like to display an isometric view of an object. So i don't want things to appear smaller if in a distance, etc. ...
6
votes
1answer
5k views

Help understanding gluLookAt()

I am fairly new to openGL( 3 months ) and am asking for assistance in understanding the fundamentals behind gluLookAt(). Currently I have spent most of my time with openGL modeling scenes with fixed ...
7
votes
2answers
621 views

Portal Projection

Ok ok I admit, I'm bored and toying with a portal script like the one on steam. I've figured out the following: relative positioning of the mirrored cameras render to texture for the portal (the ...
1
vote
1answer
2k views

Restoring projection matrix

I am learning to use FBOs and one of the things that I need to do when rendering something onto user defined FBO, I have to setup the projection, modelview and viewport for it. Once I am done ...
8
votes
3answers
919 views

Inverted textures

I'm trying to draw textures aligned with this physics body whose coordinate system's origin is at the center of the screen. (XNA)Spritebatch has its default origin set to top-left corner. I got the ...
1
vote
2answers
830 views

Rotate around a 3d Object (Software Renderer)

I have a simple 3d software renderer (SDL / C++) which can load a 3ds Model and render it (shaded) and rotate it around X Y Z - Axis. Now I would like to rotate / move around the object, meaning, the ...