Voxel Space

nine_k 19 minutes ago | parent | next [-]

Technically this is not related to voxels ("volumetric pixels", so to say), which split the 3D space equally along all three axes. This is just a height map, a set of prisms, not entirely unlike a Doom map. Every prism has a regular fixed-size square base.

For 1992, this was mind-boggling though.

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Jare 25 minutes ago | parent | prev | next [-]

[Edit] ah ok they clarify later as a performance enhancement. I think it was pretty integral to the algorithm, but ok.

Wait why do they say painter's algorithm. Comanche and other such voxel terrain engines went front to back and never had overdraw.

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s-macke 9 minutes ago | parent | next [-]

Author here. Yes, it is integral. I chose this approach to first show how to draw it from back to front, because the code is easier to understand this way.

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swiftcoder 21 minutes ago | parent | prev [-]

Reverse painters algorithm is still painters algorithm. You trade off the cost of a full screen clear before the frame, in return for eliminating overdraw

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knome 12 minutes ago | parent [-]

You could avoid a full screen clear by using the y-buffer to draw in sky segments after rendering terrain.

	▲	swiftcoder 11 minutes ago \| parent [-]
		You still need to have some sort of mask to tell you which pixels have not yet been written this frame

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a1o an hour ago | parent | prev | next [-]

When this was first posted I made a game with a port of this approach to AGS Engine. Nowadays AGS is much faster since we have improved a lot of things, but this wasn’t the case at the time, so I had to make a few little tricks to make the rendering work well with the engine at the time.

https://github.com/ericoporto/i_rented_a_boat

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tdeck an hour ago | parent | prev | next [-]

It's interesting that the color maps seem to have shadows "built in", so that you get a 3D bevel effect from just looking at the color map.

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esafak 18 minutes ago | parent | prev | next [-]

I remember how groundbreaking Comanche was. Now I learned that it was a result of the programmer's experience in the medical industry (CT/MRI scanning): https://en.wikipedia.org/wiki/Voxel_Space

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TheChaplain an hour ago | parent | prev | next [-]

I really love this kind of articles, so much to learn.

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taneq an hour ago | parent | prev [-]

If you render columns instead of rows you can render near-to-far without a Y-buffer and with zero overdraw. :)