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23
votes
3answers
2k views

Conveying a claustrophobic atmosphere in cavalier oblique projection

I need your collaborative knowledge in finding the best way to graphically represent a scene in a manner that would suit a SNES-era rôle-playing game. I've chosen to represent the game in what I'm ...
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 ...
16
votes
5answers
9k 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 ...
16
votes
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 ...
15
votes
1answer
874 views

Keystone Correction using 3D-Points of Kinect

With XNA, I am displaying a simple rectangle which is projected onto the floor. The projector can be placed at an arbitrary position. Obviously, the projected rectangle gets distorted according to the ...
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 "illusion"...
13
votes
1answer
586 views

Orthographic unit translation mismatch on grid (e.g. 64 pixels translates incorrectly)

I am looking for some insight into a small problem with unit translations on a grid. Update and Solved I solved my own issue. See below for details. Everything in this part of the post turned out to ...
12
votes
3answers
1k 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. ...
10
votes
1answer
797 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 ...
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 ...
9
votes
4answers
369 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 ...
8
votes
3answers
4k 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 game?...
8
votes
1answer
892 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
969 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 ...
7
votes
2answers
972 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.
7
votes
2answers
694 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 ...
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 ...
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. ...
5
votes
2answers
973 views

If I project a sphere in 3D will it be a circle?

Assuming I have infinite vertices to represent the sphere, if I project the sphere from any position/scale in 3D to 2D, will it be a circle? I know it will not be a circle on the screen, because of ...
5
votes
2answers
550 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)? I'...
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 ...
5
votes
3answers
623 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 ...
5
votes
2answers
1k views

Draw a 3D object at specific coordinates on the screen

I'm creating an application which allows the user to manipulate 3D models. I would like to draw 3 axis representing the world coordinate system in 3D in order to give the user an idea where he is. ...
5
votes
1answer
203 views

Composite 3-D and 2-D using Anamorphic Projection?

I'm working on a game which takes place on a two dimensional grid similar to the fluid background grid in Geometry Wars. It is implemented as a procedurally drawn spring system which may have force ...
5
votes
2answers
567 views

Calculate new coords of camera after a 90 degree rotation in an isometric 2D projection

I made a 2D isometric renderer. It works fine but now I want to show my scene from 4 different points of view (NE NW SE SW) but, on a 90° rotation, my camera cannot keep the center of my scene on ...
4
votes
2answers
475 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 ...
4
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 ...
4
votes
1answer
1k 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 ...
4
votes
1answer
509 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 ...
4
votes
1answer
170 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 ...
4
votes
1answer
2k 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 ...
4
votes
1answer
705 views

How to do perspective projection “parallax” but without changing the scale or offset of objects?

Hello everyone I have this problem that I have tried everything I could think of. The problem: I am making a 2D game with parallax effect but I am using 3d space so am not simulating the parallax but ...
4
votes
1answer
2k views

How do I convert a cube map to an equirectangular projection?

I have a cube map texture showing a surrounding area, which I want to pass to a program that only works with latitude/longitude maps. How can I do this? In other words, I need to turn this: …...
4
votes
0answers
66 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 ...
3
votes
2answers
1k views

What is Clash of Clans projection called?

What is Clash of Clans projection (it doesn't seem to be isometric! enter image description here ) photo from here
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 ...
3
votes
2answers
189 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) ...
3
votes
1answer
441 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, ...
3
votes
2answers
698 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. ...
3
votes
1answer
3k 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 ...
3
votes
2answers
2k 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 ...
3
votes
2answers
915 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 ...
3
votes
1answer
623 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 ...
3
votes
1answer
95 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
votes
1answer
592 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?
3
votes
1answer
1k views

Silly question about perspective correct texture mapping

OK, I'll admit, the math on a perspective projection matrix is quite hairy for me, but I get the general gist of it: morph the object so that it looks... perspective-ish. But there is one thing which ...
3
votes
1answer
543 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 ...
3
votes
1answer
63 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 ...
3
votes
1answer
529 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 ...
3
votes
2answers
979 views

Draw a projection of a mesh on a surface

I have a mesh looking almost like a cylinder, the cylinder goes through a mesh and continues on the other side. What I want to do is to draw the projection of the cylinder on the mesh. So if you look ...