All Questions
Tagged with projections 3d
35
questions
14
votes
1
answer
27k
views
What's the difference between orthographic and perspective projection?
I have been studying computer graphics, from the book Fundamentals of Computer Graphic (but the third edition), and I lastly read about projections. Though, I didn't exactly understand what's the ...
- 275
6
votes
1
answer
785
views
3D projection that increases objects' size as they become more distant
tl;dr Is there a name for a type of (non-physical) projection that causes objects to become larger the farther they are from a camera?
With a fisheye projection, an object twice as far from the ...
- 195
5
votes
2
answers
228
views
How to get the transform amount from a screen vector and a direction vector?
I am working on the move tool in a 3D modeling software. I need to know how much to move when the user drags an axis of the gizmo (for example along the x axis).
I have the 2D vector describing how ...
- 377
5
votes
1
answer
166
views
Where should I project a polygon corner when it is behind me?
I am creating a simple 3D engine as a learning project to get the hang on spherical trigonometry. I am using the following approach.
1. A model consists of a lot of triangular faces.
2. Each triangle ...
5
votes
1
answer
167
views
Project quad onto ellipse in 3D
I have three points P0, P1, P2, which are located on an arbitrarily oriented ellipse in 3D space. I have a square texture map with a circle on it. I would like to render a textured quad (with the ...
- 151
4
votes
1
answer
313
views
Creating Sparks using Code
I'm new to this area and have less knowledge. I want to create some graphics like sparks and lightning by writing some code, using my own physics. I don't want to use some engine, However I can use ...
- 41
4
votes
1
answer
1k
views
How to derive Field of View (FOV) angles from a 2D projection
I'm looking for some guidance.
I'm not sure if this is possible, and I'm not sure where to start.
I need to measure the FOV angles of a first-person, 3D game using only gameplay screenshots.
I'm bound ...
- 51
3
votes
2
answers
277
views
$(x, y, 1)$ is 2D homogenous coordinates or 3D homogenous coordinates?
We know that $(x, y, 1)$ are the homogenous coordinates of a 2D point $(x, y)$. $(x, y, 1)$ has 2 degrees of freedom. That's why we should call it 2D homogenous coordinates. But many websites say it's ...
- 211
3
votes
1
answer
862
views
Difference between 2D and 3D pipeline
2D transformation and viewing:
The camera projects the 2D world co-ordinate $(x_w, y_w)$ on its projection plane which co-ordinates $(x_v, y_v)$.
3D transformation and viewing:
The camera projects the ...
user17337
3
votes
3
answers
3k
views
3ds max: Z-fighting when working with Large Objects
I had a z-fighting/z-clipping issue with a scene containing some very large objects yesterday in 3ds max. It can be seen in the image below:
For some reason downscaling the scene significantly (a ...
3
votes
0
answers
98
views
Possible approach for product mockup creation including distortion created through perspective
I am not an expert in 3D nor computer graphics. Please forgive me if I use wrong wording.
High level problem description: For an online shop, I would like to create mockup images of apparel (t-shirts,...
- 131
2
votes
1
answer
16k
views
How to derive a perspective projection matrix from its components?
This has been haunting me for several days now. I want to find the component that makes up of this 4x4 perspective projection matrix, with $l$(left), $r$(right), $b$(bottom), $t$(top), $n$(near), $f$(...
- 207
2
votes
1
answer
221
views
$P^2$ vs projection plane
I want to explain what I understood of definition of the two things.
Projection plane:
The general processing steps for modeling and converting a world coordinate description of a scene to
device ...
user17337
2
votes
1
answer
425
views
3D homogenous coordinates versus 4D homogenous coordinates
We know that any 2D point $(x, y) $which represents as 3D homogeneous coordinates is of the form $(x, y, 1)$ which is the points of projective plane $P^2.$
If I use the same concepts for 3D points $(...
- 211
2
votes
1
answer
121
views
Y axis inversion in 3D rasterization
What is the correct way to invert the y axis during the 3D projection?
I see a lot a people doing:
...
- 269