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1answer
50 views

Replicating a worldspace sphere on screen space

I have quite some struggle with a post processing shader that I'm working on. I use Unity, and I have a shader in which I want to, in screen space as part of post processing, render a sphere that ...
3
votes
1answer
71 views

Problems with converting from Screen Space to World Space

I have an unproject function I've written, which takes in x and y values between -1 and 1, and a z value between 0 and 1 (0 is near plane, 1 is far plane). I create a vector off of this, and multiply ...
3
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0answers
59 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 ...
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0answers
19 views

Projection type/camera angle in Alien Soldier

I am trying to build a 2D game similar to Alien Soldier from oldies (Sega Genesis). The problem I am having is with assets. What kind of projection/camera angle does the Alien Soldier use for it's ...
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1answer
52 views

How to get UV coordinates for sphere (Cylindrical Projection)

I have created one sphere and I want to map onto it a texture map. But I want first to project my map texture to cylinder and then to sphere. So I want to create a function which takes as ...
0
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1answer
48 views

Projection type used in videogames

I'm trying to create a web application, to display 3D objects on canvas. To represent the 3D object I'm using an array of Points (from application's point of view, a Point - is just an object ...
3
votes
1answer
52 views

How do I convert 3D vertices and faces to 2D shapes?

I'm assuming all the math is done with projection matrices from linear algebra, but I don't yet understand how they work, and haven't found much information on them. What I'm mainly curious about is ...
1
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0answers
22 views

How to use GetViewProjMatrix().TransformVector(LineDirection) in UE4?

I try to project a 3D vector (a direction, not a position) in screen space, but it does not return satisfying results: FVector LineDirectionOnScreen = ...
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0answers
34 views

Construction of perspective matrix

Is it possible to Construct a perspective matrix by multiplying a perspective transformation with a parallel projection ? I want a perspective projection in 2D space which is calculated by ...
1
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1answer
28 views

seamless stereographic projection

i have been struggling with this problem on and off for a few years now - making a seamless stereographic projection texture mapping on a sphere where the two halves of the sphere use the projection ...
0
votes
1answer
46 views

Issue creating a dynamic seemless cube map

I have a function for building a cube map, given a location in space. I also have a system for displaying cubemaps (either loaded from images or given as a texture handle), and they work fine and are ...
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0answers
31 views

Perspective projection math help?

I have points X,Y,Z and have a camera at Cx,Cy,Cz. Assuming the camera is not rotated and is facing the -Z direction and is at 0,0,0. What would the math be for projecting the X,Y,and Z values onto ...
0
votes
2answers
81 views

3d projection help?

I've been wanting to know how to do 3d projections. Can someone explain how i can use this to find the position for x and y on the 2d plane that is 600 * 600 pixels.
3
votes
1answer
248 views

How do I convert a panorama image into a skybox?

I have two panoramas (1, 2) that are the same but are shaped a little different. I don't care which one, but how should I go about converting them into a Skybox? I was looking for something like ...
15
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1answer
2k views

What projection is this?

Could someone tell me what this projection is called? It's as if you are looking at an object from directly above it and then smear it up and left equally. Only the one dimension seems to be true ...
0
votes
0answers
50 views

Perspective projection

I'm studying Perspective projection in a computer graphics course and i'm really confused about a detail. The study material says there are 3 cases: Case 1: View plane parallel to the xy plane and ...
1
vote
1answer
53 views

Does projection take place before clipping in the rendering pipeline?

At first I thought clipping happens before projection since new vertices may be added and the output of projection is in NDC which is 2D. However after a lot of googling, I found that some ...
9
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4answers
273 views

How do I correctly project a point behind the camera?

I am making a 3D game in which I put an exclamation marker above points of interest. In order to find out where in the 2D screen should I put my marker, I am manually projecting the 3D point where ...
0
votes
1answer
149 views

How to draw 2d above 3d scene?

I have an OpenGL(3.3)+GLEW application. I want to draw a black vertical rectangle at the left side of the window for writing some information on it, like fps (I use GLEW function for drawing text). ...
0
votes
1answer
494 views

How do 3D games create the illusion of depth?

How do libraries like OpenGL convert three dimensional coordinates into the two dimensional pixels we see on our screens? I'm not talking about the 3DS or games that require 3D glasses, but rather the ...
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0answers
65 views

How to convert Screen-space translation into World-space translation

private void Translate(SceneMouseMoveEventArgs args) { var camera = args.Camera; origin_screenspace = camera.UnProject(_position).Xy; cursor_screenspace = new ...
0
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1answer
53 views

Projectile Shoot three at a time

In my game there is a bird flying and on touch it throws different artifacts projectile downwards. And these artifacts should hit the containers moving right to left on the screen. Now if user keeps ...
4
votes
2answers
442 views

How can I achieve a pseudo-3D camera effect like this?

I am trying to achieve a pseudo-3D camera effect similar to this: I have gotten the following results using a 3D camera and billboards: I am now running into the following problems: In the ...
2
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2answers
3k views

What is the difference between an orthographic and oblique projection?

They both seem to be a parallel projection. I know that the angles of axes of viewing differ based on the type of orthographic projection (eg, an isometric projection has equal angles for all the ...
2
votes
1answer
118 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. ...
0
votes
1answer
266 views

Distortion problem with perspective projection

For various reasons – partly educational, partly technical – I'm writing a 3D game engine from scratch, using OpenGL 3.0; aiming for Core Profile, eventually, so of course I'm using a custom matrix ...
0
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0answers
81 views

Perspective Projection Far Plane Not Clipping?

I've just discovered that far away objects in my world don't seem to clip like they should with a perspective projection matrix. When I fly far away from my main landscape, so that I am much more ...
2
votes
2answers
189 views

How to calculate a 3D orientation from 2D vanishing lines on an image?

Let say I have a image that represent a 3D scene. I did not have the 3D camera orientation of that scene (left, up and forward vectors) and i'd like to calculate it. On that picture, I draw the ...
0
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1answer
135 views

Perspective Projection - Drawing Lines

So I sort of understand the math behind projecting 3d points onto a 2d plane. It's just some simple dividing and multiplication of distances. However I can't seem to wrap my head around projecting ...
0
votes
1answer
145 views

GameObject is only rendered when it has a negative z scale

I have an orthographic camera that looks like this: I create 2d polygonal meshes that have uniform z values in their vertices. I use Camera.ViewportToWorldPoint() to map these viewpoint vertices to ...
0
votes
1answer
97 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 ...
0
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1answer
155 views

Mesh Generation In Code [closed]

My camera looks like this: I am trying to add 2D polygons to the screen based on the percentage that they take up of a 1920x1080 pixel canvas. Therefore, I calculate this and then use ...
4
votes
1answer
380 views

How to compute point in view space from depth?

I am trying to implement do some screen space rendering but after looking over the web I still don't find answers to some doubts. First, I need to compute the point in view space from a value in the ...
0
votes
0answers
143 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
2answers
701 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
157 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
108 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
510 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
74 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
150 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
167 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
475 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
69 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
1k 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
3k 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
155 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
183 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
374 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
1k 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 ...
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2answers
966 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.