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The C modest god

A question about nox graphics

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Some time ago there was a game called nox, which was similar to diablo. My question is, how they did the shadow effects in nox? was it done in software rendering? was their engine partly software and partly hardware? maybe blitting images with hardware and then doing the shadows with software? Another question, can nox graphics be done today entirely with hardware? maybe with the programmable abilities of today's graphics cards?

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Guest Anonymous Poster
If my memory serves me correct Nox is a p133 class game and is dx7 game. This would to me say they used the inverse idea of what you are thinking, it would not be to draw a shadow but not to draw in the shadow if you get what I mean. The rendering engine would have been software with a hardware blitter.

The level was probably made up out of tiles. The outside edges would have been simple line data. Do ray casts from the player against these lines. Find which tiles are in the visible area and then draw them. Then calc the triangles formed by the clipping data and use a simple software rasteriser to blit black over them. Or even just using a look up table, or you could just use an idea like the quad tree algorithm and just iterate down until you got to the single pixel level while being able to fill in largish blocks in black.

You could make the levels out of 3d data and use a directional light but you would have to add some light occlusion system as hardware lights pass through polygons, this could all be done with vertex shaders. Like the flashlight in Luigi's mansion or doom 3.

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Quote:
Original post by Saruman
Nox did not require 3D hardware at all actually only a 2MB video card minimum spec. Nothing was actually done in hardware.

2D graphics cards have also hardware accleration.
Actually simple blitting is the only hardware acceleration.
I believe nox did use the hardware blitting, because doing everything in software, even if its only 2D graphics is always slow. I am talking from my own experiance.

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If I remember correctly, Nox used an isometric software rendering engine. I haven't seen the engine in a long time, but I suspect the shadows were done either with the basic equivalent of lightmapping or by creating very simple dynamic shadow maps and alpha-blending them onto the rendered image (to be honest I can't remember if the shadows were dynamic or not; if so, the second case is more likely).

It would be very easy to do this today entirely in 3D hardware. Even simple techniques like billboarding and alpha-blended textures could easily be used to produce an isometric engine that could take advantage of 3D accelerators. Nothing so sophisticated as programmable shaders would be required by any means, although you could probably find some cool effects to do with shaders.

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I believe it uses software rendering entirely.

I don't know exactly how they do the shadows, but it's extremely clever whatever it is.

And nice and fast.

I think "p133 level game" is not quite accurate, the box says 266mhz P2. It requires quite a quick CPU to handle all those amazing lighting / shadow effects in software rendering.

But still, an excellent example of what can be done with software rendering.

Unfortunately it's a pretty linear game. There is only one way of completeing the game (as any given class), and hardly any optional quests.

Mark

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It's not really shadows like Diablo II, but a representation of field-of-view like Ultima (but much more advanced). But yes, it's rather impressive considering it's done without 3D hardware. The edges are soft, and they rotate smoothly as your character moves, which leads me to believe they're generated algorithmically rather than with shadow maps. If you look closely, you'll also notice the tiles cutting off outside the visible area, while smaller objects (like rocks) fade. I don't know how they did it, but there's an article here that discusses a similar (and I think better) approach.

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