Computer Graphics Stack Exchange
Computer Graphics Stack Exchange

Questions tagged [rasterizer]

For questions related to the rasterization process, both in terms of GPU hardware and algorithms related to rasterization.

Rasterization is the process of turning shapes into fragments. This is commonly done through ROPs (hardware), but it can be accomplished through software as well.

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How are mipmap levels computed in Metal?

My question is specifically in regards to Metal, since I don't know if the answer would change for another API. What I believe I understand so far is this: A mipmapped texture has precomputed "levels of detail", where lower levels of detail are…
lcmylin
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Why do GPUs still have rasterizers?

Despite advancements modern GPUs still have fixed rasterizers. Highly customizable, with programmable shaders but nevertheless not fully programmable. Why is that? Why can't GPUs be simply massively parallel devices with universal computing units…
zduny
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Why do adjacent triangles never overlap when rasterized?

Apologies for the following noob question, it's just I can't find a satisfactory answer anywhere... When I render a simple axis-aligned quad made up of two triangles, I don't understand why there's never any visible artefacts on the diagonal edge…
Reuben Scratton
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What are sample gaps during scan conversion?

In this tutorial, It is very often the case that triangles are rendered that share edges. OpenGL offers a guarantee that, so long as the shared edge vertex positions are identical, there will be no sample gaps during scan conversion. 1 What…
AlexWei
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Fundamental drawbacks of rasterization over ray tracing

Are there any fundamental drawbacks/limitations of rasterization as compared to ray-tracing? When I search on the internet, I get vague explanations like rasterization does not provide lighting effects as good as ray-tracing. It means that…
Nagabhushan S N
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Subsurface Scattering Without Rays?

Some games claim to use subsurface scattering but my current understanding of sss is only achieved with ray tracing. How would you sub surface scatter without ray tracing? Do some claim to use sss but really use some approximation trick that doesn't…
Andrew Wilson
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What modern real-time rendering applications still use fragment shader depth writes / late-Z?

It is pretty well known that writing depth in your fragment shader generally disables "early Z" test/write optimizations that modern GPUs rely on for fastness. Nonetheless, APIs still allow it and GPUs still provide support for correct visibility…
GroverManheim
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Why is the scan line filling algorithm so seemingly over complicated?

It makes use of tables, buckets, and sorting, which all seem unnecessary. I don't understand why I can't just fill between pairs of scan line intersections, ignoring vertices and edges with gradient 0. My lecturer didn't provide the best notes on…
toastedDeli
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Can meshes be reused in raytracing?

In rasterization, at least in the context of game development, it is a common to have many instances of the same 3D object in a scene (think many identical rocks in different sizes/positions/rotations) and to render them by only putting the 3D…
Ilya
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Mirror Reflections: Ray Tracing or Rasterisation?

Are mirror-like reflections in computer graphics purely handled with ray-tracing/ray-casting techniques or are there some situations where they are achieved through rasterisation?
Will D
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How to rasterize a line when the background color is not always white?

I've to rasterize a line taking into account not only the background color of the screen, which is white, but also the color of other objects in the scene. In my case, I've just another object, a sphere, which is actually visualized using a ray…
user4718
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Polygon Filling rule - even odd OR orientation of the normal

I am going through some ideas that slice a 3D model and fill the area of the resulting polygon contour . Currently they are using the following concepts as follows: Every resulting line of the polygon after the slicing operation has a parent…
sajis997
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How is lighting done in Rasterization based pipeline?

So I wanted to know how do Game Engines like Unity3D and Unreal do lighting. I'm familiar with Ray-tracing, pathtracing based renderers etc. But not much with rasterization based engines. I do know a general overview of OpenGL's pipeline and things…
gallickgunner
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How to align Ray Marching on top of traditional 3D rasterization?

I'm trying to apply raymarching on top of 3D rasterization, ordering what 3D object gets displayed based on the depth of a rasterization pass and the raymarch depth. After getting the transform right for position (using the information here) I was…
Krupip
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Clipping for perspective projection

In the following two graphs, the red lines are borders of the perspective-projection frustum, the blue lines are to be rasterized, the green lines are perspective-projection lines, which are wrong. How do modern GPU pipelines do such clipping…
chaosink
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