3D in jagstudio

[+CyranoJ]

27 minutes ago, OVERRiDE said:

I actually thought the programming manual states that there is no framebuffer on the Jag, with some B.S. reason that this made developers write more efficient code lol.

 

But in practice, I guess you could just allocate an address in RAM and write all of your rasterized triangles to that as a framebuffer, then display that framebuffer as 1 sprite using the OP?  If that is the case, how is the blitter used?  I imagine for faster writes of your rasterized triangle pixels to RAM?  Or is the blitter necessary to write back to RAM from the GPU?

 

I say this having experience writing 3D API's for other systems, but still trying to figure out how this was intended to work on the Jag.

 

You'd set up a framebuffer as a sprite, as you said, and double/triple buffer it, drawing 'offscreen'.

The blitter was intended to draw lines to fill in triangles generated by your software rasteriser.

Other than some very basic commands on the GPU to accelerate the math there is nothing else in the machine 3D related.

 

Now, I've been on the forums long enough to have participated in many, many pointless arguments (a few of which I have regrettably been involved in and, yes, some I'm damn glad to have said what I said) so I feel qualified to be able to identify yet another one

 

To say it was designed for 3D is incorrect, as it has virtually zero capability to do it. 

To say it wasn't designed for 3D is incorrect, as it can certainly do some nice stuff with gouraud flats.

 

All 3D renderes on the Jaguar are software renderers, using some very specific hardware commands for some of the math, and the blitter for line drawing.  

 

You are both correct, and you are both wrong.

 

 

You are going to have to agree to disagree.

 

As for the 'technical manual' ....

 

[42bs]

2 hours ago, OVERRiDE said:

I actually thought the programming manual states that there is no framebuffer on the Jag, with some B.S. reason that this made developers write more efficient code lol.

 

But in practice, I guess you could just allocate an address in RAM and write all of your rasterized triangles to that as a framebuffer, then display that framebuffer as 1 sprite using the OP?  If that is the case, how is the blitter used?  I imagine for faster writes of your rasterized triangle pixels to RAM?  Or is the blitter necessary to write back to RAM from the GPU?

 

I say this having experience writing 3D API's for other systems, but still trying to figure out how this was intended to work on the Jag.

Just look into the sources of STNICCC2000 or Nostalgia or solidYARC or jagpolygon for examples how to do polygon drawing on the Jaguar.

[saboteur]

You have to remember that a number of the design team started of at Sinclair Research and worked on the LOKI project.

 

Sinclairs design philosophy was always to invovate on the cheap and leave it to the programmers to figure out stuff that pushed the hardware to the limits, just look at the ZX81 and ZX Spectrum.

 

I still find it amazing the stuff that programmers created on a 3.5mhz Z80, cheap custom ULA and a single channel beeper. It certainly was never designed to shift fast wired polygons with hidden lines or fully filled polygons in games, but it did. 

 

It seems to me thats what the Jaguar is the embodiment of and as CJ said it will do what you program it to do nothing more and it's up to the programmer to decide how to do it within the hardware constraints.

 

[agradeneu]

Just for your info, I will quit Jaguar development soon and you can feel comfy again in your bubble  that defies any concept of reality and fact.

 

Just for the sake of my loyality to CJ, I agreed to finish the remaining projects we started. 

 

 

 

 

 

 

Edited December 12, 2023 by agradeneu

[+Stephen]

And this is why we can't have nice things.

[Zerosquare]

11 hours ago, agradeneu said:

Just for your info, I will quit Jaguar development soon and you can feel comfy again in your bubble  that defies any concept of reality and fact.

Just for your info, @42bs is one of the few individuals who pioneered Jaguar homebrew development in the mid-90s, and been involved in the community ever since. Without his and a few other people' development skills, a large part of what we have today wouldn't exist in the first place.

 

So telling him "I know better than you because I can quote the technical manual" is at best awkward, and at worst insulting.

 

The games you've worked on shows that you are talented, and I believe it would be a shame for you to leave the community. However, this attitude isn't welcome.

 

TL;DR: cool down and don't read AA for a few days. Then reconsider your decision.

 

 

[LordKraken]

Not planning to dig up some more dirt, but I didn't get the feeling that Agradeneu was denying anyone's work or contribution. Working with CJ for years, he probably knows more than anyone what it takes to do all the grunt work on a beloved but complicated system. No, his anger finds its root in the consistent push back he got on the "jaguar was not made for 3d", a statement which, from the conceptors perspective, is incorrect.

 

Eric and bastian probably have a point when they say that strictly speaking the jaguar do not have the guts to be a proper and viable 3d system (although there are many games that disprove that) and on the other hands the console propose a few hardware features to ease the load for 3d engines, so I don't know really... But that's not the point! Agra consistently spoke from the conceptors perspective, and in their mind, those extra hardware features were put into the console to get 3d games up and running (and it did deliver to some extent). 

 

At the end of the day, it's quite sad to see the best developers on the system (and by developers, I do not mean programmers only) clash and then quit. What are we all getting from that? Nothing but bitterness.

Edited December 13, 2023 by LordKraken

[42bs]

11 minutes ago, LordKraken said:

Eric and bastian probably have a point when they say that strictly speaking the jaguar do not have the guts to be a proper and viable 3d system

I did not say this. At least did not intend. Only pointing out that the Jaguar's hardware has design limits which show that the designers stopped half way. Likely due to the lack of silicon space, time or money or a combination of the three. So software must fill these gaps.

 

The blitter simply cannot draw triangles. It can draw lines, solid, Gouraud shaded or textured ones. But lines. And that's the point.

As for FPS: I myself do not need 60FPS, I need a good game-play, a decent atmosphere and a quick reaction on my button presses.
 

[LordKraken]

I know Bastian I know, but Agra was only advocating that the intention of the conceptors was to ease 3d for developers, and while from today standard it seems pretty limited, it is still something that previous 16-bits system didn't provide.

 

From there you (well mostly Eric) kept repeating the jaguar can't do 3d... that is debatable, but that was never Agra point anyway.

Edited December 13, 2023 by LordKraken

[Ericde45]

i did not say that, please re-read

i said that jaguar is not designed to do 3D

if you can not 3D texture easily the whole screen, this is not design for 3D

that does not mean you can not do it using software

jaguar is designed to fast 2D for example, object processor has clearly been created for that purpose. no software code running on the Jaguar will ever be as fast to draw sprites as the object processor hardware

 

and saying stupid wrong things on purpose or by lack of practice on the console does not help to have  factual discussions here

( NO ! the blitter does not draw triangles, it can not even fill a plane )

Edited December 13, 2023 by Ericde45

[+CyranoJ]

This thread is done.