[General Algorithme] 3D engines

Jim e · Post by **Jim e** » Mon 06 Mar, 2006 3:34 am

Timendus wrote:Wow, Jim, that's pretty damn fast Is it really that fast, or did you spice up the gif?
I mean... I know you're a damned brilliant coder, but this is faster than the b/w z80 raycasters...

Sorry, I'm greater Promoter of the SE. 15mhz can really make the difference between watching the pixels load and running from enemy units.

That screenie of yours looks damm fine Tim! you can probably play with the pixel momentum to clean up the noise a bit.

Liazon · Post by **Liazon** » Mon 06 Mar, 2006 4:48 am

wow!!!!!! Tim, that's incredible. too bad it's SE only. but 84s also have hyper mode too right? how exactly do you adjust your LCD routines for that?

off topic: Jim e: I've seen that DBZ movie, but what's the mohawk guy's name (in english)?

Timendus · Post by **Timendus** » Mon 06 Mar, 2006 12:26 pm

13:22 - Restate my assumptions

Timendus wrote:Anyway, I think this is pretty much as 3D as you'll be able to get when you want to use greyscale. Unless you pre-render everything, but then you wouldn't be staying under 5000 bytes without compression like this thingy does

Or unless you've got 15Mhz at your disposal instead of a lousy 6, so you can do a proper raycaster with greyscale.

Nonetheless, I've been reading through some stuff about raycasting myself, to see if I can use any of it for this... The theory is all quite simple really, but implementing that in z80 can be a pain...

Jim wrote:you can probably play with the pixel momentum to clean up the noise a bit.

Yes, I tried that... So far to no avail. But it looks really smooth and flicker-less on my real calculator. Nice work on the RGP

@Liazon: My thingy isn't SE only, you see it running on a plain Ti-83 in the screeny. The SE talk was about Jim's GS raycaster seen here.

Post by **benryves** » Mon 06 Mar, 2006 12:56 pm

Looking very nice... you wouldn't have anything to do with a "Half Life" demo..?

Timendus wrote:I'll try "Ben style" screen sliding instead

We should refer to this as the Acornsoft Maze style, really, as that's where I got the inspiration.

Acornsoft Maze supported "thin" walls - I wonder how they did that?

I can see how it'd work for looking left and right, but for moving in and out you'd need to stretch the textures (slow, ugly?) My demo works because the walls are nothing more complex than a bunch of lines, so scaling is very easy.

Timendus wrote:13:22 - Restate my assumptions

Have to love the occasional Pi reference

Timendus · Post by **Timendus** » Mon 06 Mar, 2006 1:24 pm

benryves wrote:Looking very nice... you wouldn't have anything to do with a "Half Life" demo..?

Yes, I do

Where did you find that..?

Timendus wrote:I'll try "Ben style" screen sliding instead
We should refer to this as the Acornsoft Maze style, really, as that's where I got the inspiration.

I'll take a look at that, see if I can get some inspiration there too

Post by **benryves** » Mon 06 Mar, 2006 1:42 pm

Timendus wrote:Yes, I do Where did you find that..?

Somebody asked me to "port" it to the TI-83 Plus a long time ago; seeing this suddenly reminded me of it. I still have the source in my old Z80 Workshop folder.

Timendus wrote:I'll take a look at that, see if I can get some inspiration there too

If you find a disk image and emulator (hint: look here), load the disk into the emulator then press Shift+Break (Break will probably be mapped to F12?) at the prompt. Failing that, type *!BOOT, but seeing as most emulators use the BBC layout the * key could be anywhere on your keyboard (@ on a modern UK layout, I suppose that would be " on a US keyboard - no idea where on yours!).
I think most modern emulators have a "run disk" button that lets you point at a disk image and it'll boot it for you, though, making things easier

EDIT: Happy 1000 posts

Timendus · Post by **Timendus** » Mon 06 Mar, 2006 2:31 pm

benryves wrote:Somebody asked me to "port" it to the TI-83 Plus a long time ago; seeing this suddenly reminded me of it. I still have the source in my old Z80 Workshop folder.

That's pretty funny

That code's a total mess, and certainly not worth any port

The thingy I'm working on now was based on the same principle at first, but I extended on that to make it much smaller and give a more detailed view. And it's source is a lot better structured too than that old crap

If you find a disk image and emulator (hint: look here), load the disk into the emulator then press Shift+Break (Break will probably be mapped to F12?) at the prompt. Failing that, type *!BOOT, but seeing as most emulators use the BBC layout the * key could be anywhere on your keyboard (@ on a modern UK layout, I suppose that would be " on a US keyboard - no idea where on yours!).
I think most modern emulators have a "run disk" button that lets you point at a disk image and it'll boot it for you, though, making things easier

OMG, tape data storage, that's pretty old

I'll see if I can get it to work when I have some more time.

EDIT: Happy 1000 posts

I hadn't noticed yet

Thanks

CompWiz · Post by **CompWiz** » Tue 07 Mar, 2006 7:53 pm

Liazon wrote:wow!!!!!! Tim, that's incredible. too bad it's SE only. but 84s also have hyper mode too right?

Hey, there's sites that give you instructions for overclocking your 83/+ calc up even faster than that.

thecheat · Post by **thecheat** » Tue 07 Mar, 2006 9:02 pm

Wow, I'm liking this a LOT, heh now, we've gotten it stated that coded right, it CAN be done, now just to do it....

Timendus, I liked your demo, unfortunatly I have this feeling it's only 90 degree turns...

so the question is, where could I learn about this raycasting?

PS: who did that raycasting demo, was it someone on this forum?

Timendus · Post by **Timendus** » Tue 07 Mar, 2006 10:48 pm

I found this tutorial, it's quite clear about the process, though implementing that in z80 is still a big step

http://www.permadi.com/tutorial/raycast/index.html

That greyscale raycasting demo (SE only, mind you!) was done by Jim e a.k.a. James Montelongo.

And yes, my demo is 90 degrees turns only, and quite impossible to expand on without rewriting the engine "core". That's why I was looking for raycasting tutorials, and found that one

I don't expect to be working on this very much though, other projects are reclaiming my time again.

thecheat · Post by **thecheat** » Tue 07 Mar, 2006 11:17 pm

ah so it WAS Jim E, I have a question for him, you think you could share the code with me? I'd like to see how one of these is built, No, I won't spread the code, it stops at me, but, I'd like to try looking at it!

Also, I just happen to have a SE (84) so, all this is possible for me... I hope... now if only I could pull the ROM off it... and use it...

Fr0stbyte124 · Post by **Fr0stbyte124** » Tue 07 Mar, 2006 11:51 pm

You can do that with just a soldering iron, but I'd suggest buying a new one.

thecheat · Post by **thecheat** » Wed 08 Mar, 2006 12:36 am

ROM IMAGE ROM IMAGE!!!

CompWiz · Post by **CompWiz** » Wed 08 Mar, 2006 12:39 pm

thecheat wrote:Also, I just happen to have a SE (84) so, all this is possible for me... I hope... now if only I could pull the ROM off it... and use it...

Yeah, when will PindurTI support SE ROMs? It doesn't seem that it would be that hard to adapt it. Just speed it up a little, and make it have more available archive space.

Jim e · Post by **Jim e** » Wed 08 Mar, 2006 1:00 pm

It's a bit more complicated than that. It's been my goal to rewrite the SE port info that michael started.