Amiga (CD32) & voxels

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Karlos wrote:

Speelgoedmannetje wrote:
@Karlos
Those were exactly my thoughts too

So chip fiends, whats the pixel fill rate of the AGA blitter in 256 colour mode?

It's hard to give an accurate figure... but it's more or less as slow as a dead snail...

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Karlos wrote:
Ok, assume 320x200 64 colours then.

Next up assume that only foreground voxels (anything > 1 pixel wide) are rendered witht the blitter and the rest is done by CPU, if faster...

The best performace on the AGA Blitter was a 320*200*4 (ie 16 colours).

The Blitter and CPU can't reneder at the same time since they both have to access Chip RAM to do it. when I ws playing with such things, I found it was much quicker to rend the whole thing in Fast RAM chunky, then C2P, then copy the whole thing over in one go using a movem loop.

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Karlos wrote:

bloodline wrote:

The Blitter and CPU can't reneder at the same time since they both have to access Chip RAM to do it. when I ws playing with such things, I found it was much quicker to rend the whole thing in Fast RAM chunky, then C2P, then copy the whole thing over in one go using a movem loop.

I know they cant render at same time, I was thinking a two pass job if mixing the rendering between blitter and CPU.

It would be interesting to see if a blitter driven  voxel engine is remotely feasable, but I'm not the AGA basher to do it :-(

Well I gave up trying to do 3D with the Amiga Chipset, it simply isn't designed for it.

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Karlos wrote:

Speelgoedmannetje wrote:
But the pixels need to be placed 3d...

Well, you are thinking of geometry transformation. For voxel engines, such calculations are for the CPU. True 3D engines may emply hardware for this on systems that have it.

For voxels, the result of these calculations are the onscreen dimensions of the 2D 'boxes' that are drawn on screen. This is what I was musing that the AGA blitter might be able to handle ok...

I think you will find setting up the blitter  to try and draw squares on the screen takes longer than using the CPU to render everything in a fast ram Frame buffer and then use a fast CPU copy loop to pump the frame buffer into the chip ram.

This is true on an 030 at least (I never had an 020 with fast ram to test).

If you want to blit large shapes on the screen (ie 2D games sprites), then the blitter is fine, but other than that I found it quite useless. :-)

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Karlos wrote:
Oh well...I guess that puts paid to that idea :-)

You can see why I started doing graphics post RTG only :-)

I used to believe, as you did, that the AGA was able to cope with it... only after a few months of trying everthing I could think of did I come to the conclusion that my 030 was actually better than the Blitter :-)

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Karlos wrote:
Well, we are talking about block fills using the blitter. As the guys have explained, it is neither fast at doing this and at same time you'd need many thousands of them for any reasonable voxel engine...

-edit-

What a bummer...back in the day it seemed a good idea too :lol:

I've seen screen shots of your game engine... what frame rate did that get? I assume you used intuition/cybergraphics?