3DO Doom, how the wall rendering works

[Linguica]

 

Quote

Exploring how the 3DO port of Doom is rendering walls with columns, just like the original Doom, though specifically using the 3DO hardware to draw thin vertical quad cels. We are getting into the tricks to achieve horizontal and vertical alignment and texture repeat, as well as light diminishing, something that in a single big quad filling a wall segment would be way harder if not impossible. By the end, I show a piece of code related to all the flags and bits relevant to the manipulation of individual quad cels used for the column rendering.

 

[Kroc]

I loved this, the graphical presentation was outstanding. I really want to see where this goes now. I hope that someday someone creates a true-3D PSX DOOM using gourad shading, it'd be almost certainly less choppy. I can see with this video just how hard the 3DO has it without shading or texture offsets.

[Remilia Scarlet]

Interesting, I've been wondering just how to visualize 3DO cel engine.

[Optimus]

Hi, thanks for posting that. I was posting the news on various sites and forgot to post on my favorite Doom forum, then I see it here :)

I plan to start with the second part just right after my xmas/new years eve holidays, and publish somewhere inside January/February.

[Optimus]

I have released the second part of these series.

 

 

[Kroc]

This has been great, I really enjoy this series as there's very little good videos out there about 3DO hardware. I've never known about the combined HW/SW floor/ceiling rendering - a clever way of working around the lack of texture offsets in the hardware. Your visualisations are great! Can I suggest that when the white pixel moves through the texture (showing the reading point) that it fades out as it goes so that you can see a reading 'tail', as after YouTube compression, the fast moving white-dot becomes much less clear.

 

Please keep producing these videos, even if you're only covering a small part of the rendering, we all want to learn more about the quirks of the 3DO and its DOOM port (and if it could ever be improved)

[Optimus]

On 05/03/2018 at 1:39 PM, Kroc said:

This has been great, I really enjoy this series as there's very little good videos out there about 3DO hardware. I've never known about the combined HW/SW floor/ceiling rendering - a clever way of working around the lack of texture offsets in the hardware. Your visualisations are great! Can I suggest that when the white pixel moves through the texture (showing the reading point) that it fades out as it goes so that you can see a reading 'tail', as after YouTube compression, the fast moving white-dot becomes much less clear.

 

Please keep producing these videos, even if you're only covering a small part of the rendering, we all want to learn more about the quirks of the 3DO and its DOOM port (and if it could ever be improved)

 

Thanks.

 

Good point about the dot circle, in fact as I was in a hurry to finish this video (It was taking longer than expected and had to finish early so that I focus in other things), I omitted some more things I wanted to add, like dotted line or vector through the movement of the dot circle, to show the steady slope. There were also 1 and a half parts I didn't added, but can easily be explained in another complementary video. I might go further with more 3DO specific videos, like a primer on cel rendering, or if I find the time to continue working with the Doom source, I might discover more stuff that I find interesting to explain or at least show my progress on optimization (there are one-two interesting tidbits I can show in Doom 3DO that are also relating with some interesting rendering bottlenecks on 3DO, I'd definitely make few short videos when I make some tests and reach some conclusions).

Edited March 6, 2018 by Optimus

[Job]

I didn't really understand most of this, because I was spacing out listening to the speaker's voice. That guy has a gift for relaxing people.