9
votes
Accepted
Parallelism in GPU's rasterization process
Different GPUs use different tricks and techniques so this answer will intentionally be very generic and some detail may not apply to some GPUs, past, present (2017), and future.
This mostly applies ...
- 12.1k
3
votes
How do you draw a straight line between two points in a bitmap?
Here is an extremely simple way of drawing lines. The function can easily be changed to be used in projects.
...
- 31
3
votes
Accepted
How to draw a smoother solid-fill circle?
The midpoint circle algorithm calculates a raster path by selecting pixels which are as close as possible to solutions of \$x^2 + y^2 = r^2\$. At each step, the path is extended by choosing the ...
- 13.3k
2
votes
Accepted
Why does my triangle rasterization miss some pixels along one edge?
Turns out I needed to fully calculate the Gamma, instead of doing that shortcut.
That solved the issue!
- 31
2
votes
Why is the depth test not done on geometry before rasterization?
You can determine if a triangle is behind another triangle. However, that's not the operation you would need to do if you wanted to do culling at the triangle level. You would have to determine if ...
- 1,247
2
votes
Details of what GPU actually do when clipping in 4D homogeneous space?
Clipping is done in 3D space before 'w' division, not in 4D space.
The GPU finds either just the near and far planes, or all 6 3D planes of the view frustum and clip the Geo to this.
If w division ...
- 12.1k
2
votes
Accepted
Opengl in 500 lines point in triangle question
If I understand if you have
P = A + uAB + vAC
and you substract P on both sides then you get
...
- 202
2
votes
Accepted
Raster Graphics vs Vector graphics
Memory isn't that much of an issue as it was in the 90s.
The SEGA Mega Drive had only 64 kB of RAM and another 64 kB of VRAM. Yes, KILObyte. And it rendered at 256x224 pixels at the lowest resolution ...
- 123k
2
votes
Raster Graphics vs Vector graphics
One can think of 3D graphics as being vector. After all, despite the internal "3D World", they are still vertices and vectors, just with some fancy textures and lighting/shaders thrown on ...
- 10.7k
2
votes
Accepted
Why do I see a wireframe when rendering with conservative rasterization and disabled Z writes?
Conservative rasterization draws to every pixel the triangle even just slightly touches, including a range of uncertainty around the outside to account for rounding/snapping.
That means there's an ...
- 751
1
vote
Accepted
How do I implement floors and ceilings properly to my DOOM Style Renderer?
Problem was solved easily, but with a lot of wasted time thinking about how. The solution lies with logic: if the walls within the sector are either backfacing or not if you are outside of it, then ...
- 31
1
vote
How to draw a smoother solid-fill circle?
If you think of the circle as a cone passing through the screen, with the point being in the center of the circle, you can reformulate it in a way that's pretty easy to code. The distance from the ...
- 2,642
1
vote
Barycentric coordinates outputting coordinate outside of triangle
It looks to me like you've taken a Barycentric coordinate function designed for determining the coordinates of a point known to be inside the triangle.
It does not account for the way the sign of the ...
- 140k
1
vote
Accepted
Geometric clipping of triangles intersecting near plane
why we can't just interpolate our z values to test if the point is behind or in front of the near plane?
Because a vertex that's behind the near plane might be behind the camera entirely. That means ...
- 140k
1
vote
How can I draw filled triangles in C++?
A relatively fast algorithm in pseudocode:
...
1
vote
Accepted
How can I draw filled triangles in C++?
There's plenty of different rasterization algorithms, but many articles you find these days are optimized for systems with fast floating point math. For your use case, the ones on this page would ...
- 176
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