Question About Pixel Shaders

[No Limit]

Hi,
I am thinking of making some maps once Valve releases an editor but I have a few questions about shaders as I don't understand them fully.

In the tech video released they were able to convert a 200,000 poly wall into just 1 poly. What is the decrease in performance when you do something like that in comparison to converting a 1,000 poly wall into 1 poly using shaders? Also, is there a limit in the number of shaders allowed in a scene?

Thanks,
Paul

 

[The Dark Elf]

Check my normal map thread in this section, thats what they use to do that wall texture, they built an object then baked the normal info onto a flat image to map onto a poly. They used XSI's realtime shaders to show how it looks directly in XSI.

As for shaders, the fancy DX9 ones the hardware does, so they work nice n fast cause the software and cpu doesn't take the hit using them

no idea yet if there's a limit.

 

[No Limit]

Originally posted by Fenric1138
Check my normal map thread in this section, thats what they use to do that wall texture, they built an object then baked the normal info onto a flat image to map onto a poly. They used XSI's realtime shaders to show how it looks directly in XSI.

As for shaders, the fancy DX9 ones the hardware does, so they work nice n fast cause the software and cpu doesn't take the hit using them

no idea yet if there's a limit.

That's a very informative thread, thanks. However, I need to know of the performance hit when using this method on more complex objects and the articles posted in that thread don't go over it.
Paul

 

[The Dark Elf]

Well being hardware based. It'll depend on the card you use as to how well the DX9 shaders perform. Normal maps and spec maps wont have a too big a hit on performance. If you have tons of lens shaders all interacting with each other there might be some hit. But for the most part it should be ok. Those cables in the E3 vids are shader based apparantly and they don't appear to slow things down. eyes and water are other DX9 shaders, they don't seem to have made too big a hit. Again, its the video card that'll make the biggest difference on performance when using DX9 shaders.. older ones like DX8 stuff and earlier wont make any real difference these days I reckon

to be honest nobody really knows for absolute sure. But I'm gonna go with the better DX9 card, better performance with the fancy shaders

 

[No Limit]

Thanks for the info. Do you know of any game that supports these so I can play around with it?
Paul

 

[The Dark Elf]

DoomIII (when its done). Max payne 2 atleast uses normal and spec maps. COD I'm pretty sure the demo makes use of them if you have the hardware to handle it

There's also a few demos on the net that show off different things in DX9 like HDR lighting, blooms, flares etc.

and of course XSI can to an extent, but can't do all of them unless you program the shaders to use with it if their not already available, meaning the realtime ones, any of them can be faked in pre-render stuff though

 

[Stitch]

Call of Duty? The QUAKE III Engine? Say it isn't so.

*digs into his code bank and takes a slice of code to make a big breasted female*

 

[Incitatus]

Originally posted by Fenric1138
DoomIII (when its done). Max payne 2 atleast uses normal and spec maps. COD I'm pretty sure the demo makes use of them if you have the hardware to handle it

There's also a few demos on the net that show off different things in DX9 like HDR lighting, blooms, flares etc.

and of course XSI can to an extent, but can't do all of them unless you program the shaders to use with it if their not already available, meaning the realtime ones, any of them can be faked in pre-render stuff though

I didn't see any normal maps in CoD. Nor in MP 2 tbh, while some of the models would have greatly benefited.

 

[The Dark Elf]

Originally posted by Incitatus
I didn't see any normal maps in CoD. Nor in MP 2 tbh, while some of the models would have greatly benefited.

I'm pretty sure someone said it had them. I wont get them though, no DX9 card.. looks pretty cool without though so I'm not too fussed, really gotta get my arse in gear and get into town and buy it, the demo is too short

 

[Brian Damage]

Speaking of pixel shaders, does anyone know how you could implement iridescence?

 

[Incitatus]

Originally posted by Brian Damage
Speaking of pixel shaders, does anyone know how you could implement iridescence?

hmm tricky, it's difficult enough in a package like max. Of the top of my head, you could try an animated spec map, if that's possible in HL2. Of course this isn't true iridescence because colors would change independent of your movement.

The difficulty is in tieing the colors to the players movements.

That would be a vertex shader solution obviously, I know pretty much shite about pixel shaders.

:afro:

 

[Brian Damage]

Well, they could do it in Halo on a piece of crap like the X-Box...

 

[Incitatus]

Oh I'm sure it's very possible and wouldn't be very cpu intensive. But I can't think of how especially using vertex shaders. I'm sure you could code it, but I know as much about coding as I do about pixel shaders

:afro: