Tagged Questions
3
votes
2answers
125 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
91 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 ...
0
votes
0answers
57 views
Uses for vector projection?
My previous question was solved by vector projection. Thus I spent some time studying it (Few helpful links: Interactive projection, short video and a longer video.).
There were plenty of sites that ...
2
votes
1answer
188 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
0answers
92 views
Numerically stable(ish) method of getting Y-intercept of mouse 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...
...
12
votes
1answer
206 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 ...
2
votes
1answer
310 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 ...
0
votes
0answers
98 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 = ...
5
votes
3answers
645 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
3answers
675 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 ...
2
votes
1answer
577 views
How to create projection/view matrix for hole in the monitor effect
Lets say I have my XNA app window that is sized at 640 x 480 pixels. Now lets say I have a cube model with its poly's facing in to make a room. This cube is sized 640 units wide by 480 units high by ...
14
votes
3answers
1k 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 ...
7
votes
1answer
352 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 ...
12
votes
5answers
2k 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 ...
