Questions tagged [projection-matrix]

The tag has no usage guidance.

18 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
3 votes
1 answer
5k views

Deproject Screen To World Coordinates (Unreal Engine 4.15)

I am working on a small game in Unreal Engine 4.15 using blueprints only and encountered a behaviour I don't understand. The game is based on the Top Down Example. As I'd like to teleport an actor ...
nmnd's user avatar
  • 31
3 votes
0 answers
642 views

Control frustum near and far clip plane sizes in a Projection Matrix

I'm trying to achieve a dolly zoom effect. My first try was the obvious one, the original "zoom in & dolly out" technique, which works nicely. Except that there are cases which this is not ...
NemoStein's user avatar
  • 389
2 votes
0 answers
77 views

How to correctly rotate 2D orthographic projection around a central point?

I want to rotate a 2D orthographic projection around the centre point of my view. However, something is off (it looks like a translation) but I'm not sure what. To put some concrete values on the ...
junglie85's user avatar
  • 123
2 votes
0 answers
2k views

How to achieve the top-down (oblique) projection of textures using an OrthographicCamera?

This question is related to (How to calculate the initial velocity of projectile motion by a given distance and angle from point A to B) question. Details In the below image is the graphical ...
ronscript's user avatar
  • 501
1 vote
0 answers
44 views

How to Generate a Texture to Make an Obstructing Plane Appear Invisible in a 3D Scene?

I have a 3D scene with a camera. Between the camera and the scene, I have a plane with arbitrary orientation. This plane obscures a portion of the scene from the camera’s perspective (anything behind ...
John's user avatar
  • 111
1 vote
2 answers
180 views

In a 3D projection, how to find 'w' for every y point on the screen

I have a standard 3D rendering pipeline. Let's say I have a camera looking down at a flat plane that represents the floor. (in my game, z = height, so this is a plane where z == 0), and for ...
Tom Davies's user avatar
1 vote
0 answers
288 views

How to get world coordinates from a 4X4 camera matrix

I have Intel T265 camera which has a camera coordinates system like following diagram: The camera system has two cameras and the center of the two cameras is the position of the camera system. The ...
Nick X Tsui's user avatar
1 vote
0 answers
81 views

My triangle disappears when multiplaying by my perspective projection matrix

Whenever I multiply my transformation matrix, which is passed to the shader via constant buffer, my triangle disappears. Here is the code for the passed matrix: ...
Marcin Poloczek's user avatar
1 vote
0 answers
78 views

Why projection window is between -1 and 1

Is it a convetion ? What we achieve with this ? I am reading about how the perspective and orthographic matrix is getting calculated and everyone is trying to normalize the homogenous coordinates to [...
ItsYou's user avatar
  • 11
1 vote
0 answers
131 views

How and where to transform a Camera Frustum onto a tilted screen?

In rendering tutorials for perspective projection the assumption is that the rendering surface is perpendicular to the sight line. As shown here: How to accommodate for a screen that is tilted ...
JeffV's user avatar
  • 185
1 vote
0 answers
57 views

Convert box to matrix

I have a box (non-rectangular cuboid?) and would like to convert it to a matrix such that when a point inside the box is multiplied by the matrix, a vector is returned that describes the relative ...
Zachary Burns's user avatar
1 vote
0 answers
1k views

How can I get shadows to appear correctly when using a custom projection matrix?

EDIT: This has been officially marked as a bug in Unity. If anyone else has this issue, you can vote here for Unity to fix it. As mentioned in this thread, I'm using a custom projection matrix in ...
Ben BearFish's user avatar
0 votes
1 answer
60 views

Setting up perspective projection in OpenGL

I'm trying to set up perspective projection in OpenGL but it doesn't work ...
DDD's user avatar
  • 11
0 votes
0 answers
41 views

How to obtain the Position on the screen (Vector2) of the Position of an object in the world (Vector3)?

I have been searching around for a solution to this but still haven't been able to use it or find it, the thing is i need the Screen Position of an object that is being seen, for this i have three ...
user57129's user avatar
  • 121
0 votes
0 answers
37 views

Is directional shadow mapping without projection matrix possible?

I have found this code where they use a cubemap for pointlight shadow and they don't need to retrieve the faceindex and the projection matrix. This greatly improve the FPS. I was wondering if this ...
philB's user avatar
  • 129
0 votes
0 answers
44 views

NDK opengl-es unknown error

Projection matrix? Renderer? Where is the error? I recently started studying NDK to create better performing android games ... but ... An error I didn't expect to deal with appeared a few weeks ago ...
Yuu's user avatar
  • 21
0 votes
0 answers
202 views

Perspective projection matrix with a non-orthogonal near plane

I'm trying to figure out a way to provide such a perspective projection matrix to a shader that the "near" plane wouldn't necessarily be orthogonal to the camera vector. More specifically, I'm ...
user3139876's user avatar
-1 votes
1 answer
1k views

Project camera-to-pixel ray in world coordinates

I'm trying to implement a very simple ray tracing function but I have a problem with projecting the camera ray (from camera to pixel) to the world space. In the screen coordinates have the pixel ...
Zick's user avatar
  • 99