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0answers
31 views

Change 2D Angle Into Isometric Angle

i Rendered My Sprite With 72 Angles In Isometric View. Rendered Frame Number 0 And Angle 0 Is When My Sprite Looking Right And And I Rendered My Sprite Every 5 Angle. In My 2D Game My Sprite Moving ...
3
votes
1answer
120 views

Mixing Perspective and Orthographic Projections?

I'm going to start with some background, so jump to my question at the bottom for the TLDR version. Problem: In a Japanese 4gamer article (english translation via Chev on Polycount) explaining some ...
2
votes
1answer
39 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 ...
2
votes
1answer
46 views

Orthogonal projections question

I'm very VERY new into the game development world and I had just some slight trouble wrapping my head around something. We were told between classes just to think about how scaling matrices can ...
0
votes
1answer
65 views

Computing Field-of-View from window dimensions

I'm looking into computing the vertical Field-of-View (FOVy) based on the projection parameters of my camera. From this source, I've found an equation that seems to work. float ...
1
vote
1answer
57 views

Rendering order for units behind objects?

Im developing a 2D game with some fake 3D effects (parallell projection). 2D-units are able to walk in front of buildings aswell as behind them, although themselves being just 2d-objects. This leads ...
4
votes
1answer
93 views

How do I deal with floating-point error given a far-away camera?

Whenever a camera is "far" away (its location is some "large" vector), trouble arises when rendering objects close to it: It is the classic precision loss from subtracting 2 floating point numbers. I ...
0
votes
1answer
128 views

How do you create a 2d world then view it in 3d?

I have been learning OpenGL for a while now and have a pretty good understanding so far. What I would like to know is if I create a 2D game in Orthographic Projection, is it possible to switch to a ...
1
vote
2answers
117 views

How to determine the visibility of a single vertex, given a viewpoint?

I have a 3D triangle mesh, and I want to know, given a viewpoint (defined by a model, view and projection matrix), if a certain vertex is visible or not. My approach was to render the mesh using ...
-3
votes
1answer
62 views

projection and matrices [closed]

Many games do just fine with two projections, that can be represented by a matrix (orthographic and linear perspective). But what about projections that can't be represented by a matrix? Can you ...
0
votes
1answer
211 views

Projective texturing and falloff

I quite understand how projective texturing works. I implemented successfully a shader for that following nvidia doc. The major problem I'm facing is that with that implementation the projector ...
21
votes
3answers
2k views

Are there 3D projections other than orthographic and perspective? [closed]

The question is pretty much in the title. Are there notable 3D projections other than orthographic and perspective that could be used in a 3D system such as OpenGL? In particular, are there any that ...
1
vote
1answer
60 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 ...
2
votes
2answers
152 views

How do I convert screen coordinates to between -1 and 1?

I'm writing a function that allows me to click on my tiles. The origin for my tiles is the center, however, the mouse's origin is the top left. I need a way to transform my mouse coordinates into my ...
3
votes
1answer
203 views

How to achieve cavalier projection using OpenGL fixed pipeline?

I want to make a quick demo program showing a cube, or a user loaded model, rotating in screen rendered with one of three projections: perspective, isometric and cavalier. Using the fixed pipeline, ...
2
votes
1answer
173 views

How do I check why is no output on screen?

I'm using OpenGL 3.3+, and I'm trying to create an orthographic projection to draw on screen. I have the model data in a buffer: X Y 0, 0 50, 100 100, 0 And I create my Model-View-Projection ...
0
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0answers
68 views

Cube projection composed of smaller cubes not lining up

I am trying to make a cube projection composed of other cubes, similar to a Rubik's cube but completely static. I can get one cube to work, but when I join multiple, they don't line up. I am using ...
7
votes
2answers
934 views

What kind of projection is demonstrated in this screenshot?

I want to know what projection is used in the following game: The game is Goodgame Empire.
0
votes
2answers
180 views

What dimensions should you use for a perspective projection frustum?

What dimensions should you use for a perspective projection frustum? Initially I created a perspective matrix based on the width and height of the screen, with a calculated zNear value based on a ...
0
votes
0answers
61 views

Rasterizing euclidean planes

I'd like to visualize a BSP tree. To do this, I need to project an arbitrary euclidean plane onto a projection plane. I was thinking about calculating the intersections of the plane with the viewing ...
1
vote
1answer
725 views

Using gluUnProject to transform mouse position to world coordinates (LWJGL)?

I have a little LWJGL application and I have been trying to figure out how to successfully use the GLU.gluUnProject function in order to transform a given point on the screen (mouse position) to world ...
1
vote
1answer
224 views

Why are there different ways of building projection matrices?

Matrix.PerspectiveFovLH documentation page says that this method uses the following formula to build a perspective projection matrix. [w, 0, 0, 0] [0, h, 0, 0] [0, 0, zFar/(zFar - zNear), 1] [0, 0, ...
1
vote
1answer
154 views

Where is the error in my perspective projection implementation?

My question is not really a game development question, but since it's based on 3D programming, I thought it would fit best here. I've got a line made out of Point3D objects where the value of x, y, ...
1
vote
1answer
74 views

Why does everything appear backwards when using orthographic projection?

I may not be calculating my orthographic projection matrix properly. What can I do to ensure that my scene renders correctly when using orthographic projection? The rendering order appears to be ...
2
votes
1answer
156 views

Is it bad-practice using left-handed coordinate system in OpenGL eye-space?

In the engine I am currently programming I want to use a left-handed coordinate system for eye-space instead of the glFrustum standard right-handed one. Is that in anyway considered bad practice?
2
votes
2answers
143 views

Trying to project a point onto a cubemap

I've got a simple test program with a camera within a cubemap (skybox). You can look around, and it feels like you're in a 3D room, but really it's just a cubemap image. Now I want to draw a point ...
4
votes
1answer
516 views

How do I ensure that perspective and orthographic projection matricies show objects at the same size on the screen?

I am working on a 3d scene editor and would like to show the scene in orthographic projection. My current problem is that I am not sure how to calculate the orthographic projection matrix such that ...
0
votes
1answer
40 views

Rotate final image with projection matrix

I'm trying to use space in my shadow (depth) maps in a more efficient way. If I could freely rotate the final image I get with projection matrix I could save a lot of pixels, but I don't know if it is ...
0
votes
2answers
288 views

OpenGL ES, orthopgraphics projection and viewport

I want to make some simple 2D game on iOS to familiarize myself with OpenGL ES. I started with Ray Wenderlich tutorial (How To Create A Simple 2D iPhone Game with OpenGL ES 2.0 and GLKit). That ...
0
votes
0answers
64 views

W2S, worldtoscreen from Projection Matrix and View Matrix

After a couple of days of tremendous trial and error coding, I must give up: I have a simple 3d program that I'm adding a visual layer to. Basically, I want to draw 2d icons and text over 3d objects ...
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vote
3answers
399 views

Orthographic Projection with variable FOV

We are building agame with orthographic view. The problem we face is the fact that with different resolution you can see different area of the game world. E.g. if you have higher resolution you can ...
0
votes
1answer
108 views

Perspective projection computation

I'm learning OpenGL from arcsynthesis and I don't understand something about perspective projection (http://www.arcsynthesis.org/gltut/Positioning/Tut04%20Perspective%20Projection.html). When the ...
12
votes
3answers
974 views

Camera for 2.5D Game

I'm hoping someone can explain this to me like I'm 5, because I've been struggling with this for hours and simply cannot understand what I'm doing wrong. I've written a Camera class for my 2.5D game. ...
2
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0answers
119 views

Unproject considering parallax depth

How can I take screen coordinates (or alternatively world coordinates on the 'primary' parallax plane) and find out what world coordinates they translate into when taking parallax depth into account? ...
1
vote
1answer
395 views

Project location to perspective fake 3D view

I am trying to implement a perspective view in a 2D soccer game, such like Nintendo World Cup. In this case, the soccer pitch will look like a isosceles trapezoid, but not a rectangle in real. Here ...
2
votes
2answers
245 views

Orthographic Zooming with 0,0 at top/left

I'm trying to implement zooming on my 2D game. Since it's using orthographic projection, I thought it would be easy to implement zooming. After looking around the internet, I found a bunch of ...
1
vote
2answers
545 views

What is the camera direction vector for an isometric view?

What values correspond to a 3D vector for screen-normal from within an isometric game? It needs to be in game coordinates. It is a standard isometric where tiles are rotated 45 degrees and half ...
2
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1answer
105 views

Minimal Projection Matrix

i hope you can help me. I'm currently stuck at the creation process for projection matrices used by shadow maps. The problem is the following: I got the spot/directional light ...
-1
votes
1answer
182 views

Pinhole matrix problem

I made a program to represent a 3D world. I use the projection matrix we can find on wikipedia. For viewing a scene it's very nice but when I straff in the scene, everything behind the camera go on ...
2
votes
0answers
130 views

Stereo 3D: drawing 2D elements at apparent screen depth

I'm developing an application making use of DirectX11's stereoscopic features. At such I am not relying on nVidia's automatic implementation. That means I have to replicate a way to render 2d elements ...
3
votes
1answer
229 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?
1
vote
2answers
240 views

projected textures not appear on the “back” of the mesh as well?

I want to create blood wounds on my character's bodies by using projected textures. I've watched some commentaries on games like Left 4 Dead and they say they use projected textures for the blood. But ...
0
votes
1answer
87 views

XNA Rendering vertices that only appear within the cameras view

I'm making a game in XNA and I recall hearing that professionally made games use a technique to only render the polygons that appear within the cameras projection. I've been trying to find something ...
0
votes
1answer
103 views

Which is the right way to build a OpenGL Projection Matrix

This time I'm trying to learn the core of matrix transformations. I dont like the idea to using a Math library and dont understand what is hapening on background, because this I'm having some ...
0
votes
1answer
315 views

Projecting world coordinates to screen coordinates issue - points disappear when origin not in view

I am trying to implement a 2d line drawing effect on a 3d mesh using Ogre. In order to do so, I perform silhouette detection on the lines of the object (this works) and then project these lines from ...
1
vote
1answer
236 views

XNA draw 3d graphics in 2d game

I am programming a simple pool game in XNA. I am using Farseer for simple 2d physics but I want to use 3d graphics. My problem is I can't get the rendering to work. I have one model for the ball and ...
3
votes
2answers
170 views

What kind of projection is ScreenX=X/Z, ScreenY=Y/Z?

I have an existing class which transforms 3D vectors and projects them on a 2D plane (Camera). The code is all written in C without help from an external library. To project a single vector (X,Y,Z) ...
0
votes
3answers
173 views

Keeping raycast on the same level

I want my raycast to end at certain height(red line). But as the game is 3D and the camera rotates I can't use a fixed magnitude. What I thought was a stroke of genius, I figured I'd project the ...
2
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0answers
70 views

uniform z slices in clip-space

1) Context I'm using a regular OpenGL perspective projection matrix created with GLM (glm::perspective) and taking the inverse (glm::inverse) to transform clip-space back into view space (and world ...
0
votes
1answer
302 views

Ways to “invert Z-axis” in shader-based core-profile OpenGL?

In my hobbyist shader-based (non-FFP) GL (3.2+ core) "engine", everything in world-space and model-space is by design "left-handed" (and to stay that way), so X-axis goes from -1 ("left") to 1 ...