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2
votes
2answers
280 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
856 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
votes
1answer
111 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
183 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
143 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
317 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
269 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
91 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
113 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
482 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
274 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
176 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
216 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
votes
0answers
78 views

uniform z slices in clip-space [closed]

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
429 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 ...
5
votes
2answers
456 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 ...
1
vote
1answer
229 views

Simulating flight dynamics in two dimensions

I have decided that in order to improve my math skills and game programming skills I am going to work on a two-dimensional space simulator. The view of the player or camera will be from inside the ...
4
votes
1answer
498 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 ...
1
vote
1answer
197 views

Drawing Projected Vertices/Faces In Order

I recently created a 3d engine, and have gotten to what is (as I've found) the hardest part so far. I need to sort the objects and then draw them. I've looked at sorting algorithms, but my case is ...
5
votes
1answer
183 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 ...
2
votes
2answers
245 views

What kind of projection is used here?

Tibia is a 2d game, but it's sprites are drawn using certain kind of orthographic projection that is not the same I'm used to: I'm trying to figure out what projection is used here. I've guessed ...
2
votes
1answer
218 views

Coordinate spaces and transformation matrices

I'm trying to get an object from object space, into projected space using these intermediate matrices: The first matrix (I) is the one that transforms from object space into inertial space, but since ...
1
vote
0answers
1k views

Black Screen: How to set Projection/View Matrix [closed]

I have a Windows Phone 8 C#/XAML with DirectX component project. I'm rendering some particles, but each particle is a rectangle versus a square (as I've set the vertices to be positions equally offset ...
2
votes
1answer
730 views

How to do geometric projection shadows?

I have decided that since my game world is mostly flat I don't need better shadows than geometric projections - at least for now. The only problem is I don't even know how to do those properly - that ...
2
votes
2answers
413 views

Unproject mouse position to tile — extremely jumpy position?

I'm trying to unproject the mouse position to get the position on the X-Z plane of a ray cast from the mouse. The camera is fully controllable by the user. Right now, the algorithm I'm using is... ...
2
votes
4answers
4k views

2D camera perspective projection from 3D coordinates — HOW?

I am developing a camera for a 2D game with a top-down view that has depth. It's almost a 3D camera. Basically, every object has a Z even though it is in 2D, and similarly to parallax layers their ...
13
votes
1answer
523 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 ...
4
votes
2answers
804 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 ...
0
votes
1answer
197 views

Scanline filling of polygons that share edges and vertices

In this picture (a perspective projection of an icosahedron), the scanline (red) intersects that vertex at the top. In an icosahedron each edge belongs to two triangles. From edge a, only one triangle ...
0
votes
1answer
306 views

Greiner-Hormann clipping problem

I have a set of planar polygons in 3D space defined by their vertices in counterclockwise order. Let's define the 'positive face' as being the face of the 3D polygon such as when observed, the ...
1
vote
1answer
162 views

Orthogonal projection and world transform

I'm reading about projection matrix. Needs of perspective projection is obvious, but I'm not sure about orthogonal projection. Because orthogonal projection effect looks possible with only world ...
-1
votes
1answer
726 views

Off center projection

I'm trying to implement the code that was freely given by a very kind developer at the following link: ...
2
votes
3answers
903 views

Game Engine which can provide 360 degree projection for PC [closed]

I'm searching Game engine which can provide 360 degree real-time projection. I've already achieved this by using VBS2 Game Engine. (Ref.: ...
5
votes
2answers
978 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. ...
4
votes
1answer
490 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: ...
1
vote
1answer
585 views

Trouble with SAT style vector projection in C#/XNA

Simply put I'm having a hard time working out how to work with XNA's Vector2 types while maintaining spatial considerations. I'm working with separating axis theorem and trying to project vectors onto ...
0
votes
3answers
231 views

Understanding how to go from a scene to what's actually rendered to screen in OpenGL?

I want something that explains step by step how, after setting up a simple scene I can go from that 'world' space, to what's finally rendered on my screen (ie, actually implement something). I need ...
3
votes
1answer
675 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 ...
1
vote
0answers
174 views

What is the connection between an isometric angle and scale

I am trying to work out an isometric projection matrix for a custom angle. In the engine I'm using there's a projection matrix defined like so: projection.rotate(45 * (Math.PI / 180) ); scale = ...
0
votes
1answer
706 views

Easy way to project point onto triangle (or plane)

I have a mesh of triangles (navigation mesh), and a point in 3d space. This point should be "over" one of the triangles all the times. I'm trying to determine which triangle is the one the point is ...
3
votes
1answer
518 views

How to compute the 2D equations of 3D circular arcs?

I'd like to obtain these equations for the ellipses produced by the perspective projections of (3-dimensionally transformed) circles. This is useful for rendering in 2D contexts which provide curve ...
1
vote
2answers
971 views

How would I achieve diablo like 2D isometric projection?

I am in the process of coming up with an idea for a game, and I would like it to be isometric like Diablo. The problem is I have no idea how it achieves the effect of height like in the following ...
3
votes
2answers
747 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 ...
15
votes
1answer
785 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 ...
1
vote
1answer
142 views

Finding furthermost point in game world

I am attempting to find the furthermost point in my game world given the player's current location and a normalized direction vector in screen space. My current algorithm is: convert player world ...
10
votes
1answer
1k 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
279 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
2k 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
491 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 ...