360 XNA game poly count limits

[Haloman21]

I am working on a project atm and well its going to be an rpg and they have some I would define crazy poly count limitation. Im not sure if the game being an xna project means that it cant use the 360 to the full potential or what but im wondering what would be a good poly limit for something like weapons for example a sword. They told me to make weapons at 200 polys or less I thought my eyes were going to explode

[Craig Lewis]

There's no real polycount limits to XNA itself, only the Xbox hardware. It all depends on how well you program your engine in XNA I would assume.

[Haloman21]

Hmm so im guessing that the programmer is just being safe with low poly limits. Would even the poorest engine have trouble with multiple 1000 poly objects do you think? I modeled a sword I know two things that we will take out the main part down the center of the sword and the rings at the crossguard. Check it out and the rest of the work I will be doing for the project here
EternalS pictures by Haloman21_2011 - Photobucket

[Tiros]

Well, it's not like it's impossible to get a good-looking sword with 200 tris, and if they refered to polygons, being 400 tris, then even better

If it's for a 3rd person xbox rpg, I think it's quite a fair spec tbh. Then again, I never worked with xbox speccs, so I might be wrong.

Have look here: http://www.game-artist.net/forums/co...bmissions.html

[Haloman21]

The sword has lots of curves and things That I would like to keep smooth O well guess i could use this model to bake a normal possibly? *shrug*

[Talon]

XNA's pretty powerful. The polycounts it can handle... I reckon you could easily look at HL2 as a reference point (i.e. 500-600 tri mark for a 3rd person weapon - although maybe aim at 300ish for most melee weapons as they're quite simple things).

Ultimately, though, you'd need to just mess around and see at what point it breaks. Throw a few really high poly objects at it, lots of really low poly ones, some animated characters... and just see where the framerate starts to falter. That'll give you a rough indication of how many polys it can handle on-screen at once.

For an RPG, though, the character is often quite small on the screen and the visual representations of the weapons is sort of secondary to the gameplay, writing, character development and questing, etc... so they do tend to be quite low poly as that means they can kick out loads of variations and can have a lot of things on-screen at once.

[cnflkt]

Check this out here.
more here too.
An insider view on poly counts of various object on various systems, makes for some interesting reading!

Looking at the figures, the Xenos pushes around 500m Triangles/sec, i dunno the math on this but on paper this should translate to 8m Tris per frame (@60fps?), however naturally in the real world I doubt Tris counts half this (see link)

Poly counts largely depend on Engine implementation and scene graph management, LOD systems, Portal culling (the general norm these days), etc.

Glad you brought this up TBH, I was looking for clarification current gen LOD

Also regard XNA, theoretically you should be able to harness the pretty much the full power of the 360, although I don't know what profiling tools that is may or may not have, so might not be able to achieve the performance the retail games have... who knows? Like I said its about managing resources and LOD these days.

[JMYoung]

If you're targeting an xbla community game, you'd have a size restriction I believe. Maybe that's being figured into the specs?

You can definitely handle normal 360 detail, though. There's no inherent limitation in XNA that makes it unable to pump out retail level quality.

[Talon]

Originally Posted by cnflkt

Looking at the figures, the Xenos pushes around 500m Triangles/sec, i dunno the math on this but on paper this should translate to 8m Tris per frame (@60fps?), however naturally in the real world I doubt Tris counts half this (see link)

A lot of those are theoretical limits.

I think something like UE3 is optimised to disply about 500,000 tris per scene and the xbox can choke on that sometimes, from what I've seen. I very much doubt XNA's built to handle anywhere near that amount of polys efficiently.

There's a very big difference between pushing raw triangles and pushing deforming triangles, with shaders, physics, particles, audio, AI and all the other stuff that goes on in the background of the game.

[Emperors Teeth]

On a different but relevant note...

We are using XNA in our pipeline and, as an animator discovered to my horror that XNA has a 59 bone limit more or less hardcoded into it. We got around this with a added community written content processor but we're experiencing bugs up the wazoo. We do get up to 79 bones now (enough for a full character with bone-driven-face).

Something to keep in mind when making characters for XNA.