10 replies to this topic

[Daz]

I've read a rumour that C&C3's version of SAGE can handle pretty much anything aslong as you minimise meshes and textures. I think this was someone misquoting the fact that poly counts aren't the biggest concern, they certainly still matter though.
I just thought I'd mention some things relating to the poly counts in C&C3 which I've found.
I've summarised at the bottom.

First some EA model poly counts:
The GDI Predator Tank (a basic, very spammable unit) is 1954 polies.
Somewhat surprisingly the GDI Mammoth Tank (a larger, more expensive, less spammable unit) is in the region of 1100 polies.
The Scrin Tripod is 2588 polies.
A GDI Rifleman is 492 polies.

I would suggest it is sensible to assume these limits have been debated and decided on as being best for good performance on the widest range of machines.
So to assure your mod works well for the greatest number of people 2000 seems a good limit for tanks and other common units. Higher tech units (like the Tripod) are probably safest up to 3000.

However, if you're quite happy to limit your audience to the top end of the spectrum the engine can manage more than these comfortably.

I tested (ie spammed like crazy) a Challenger Tank model weighing in at 4086 polies with zero noticeable slowdown.
I then added some extra geometry to bring the count to 6014 polies, again with no noticeable slowdown.

At that stage I decided to really go to town and downloaded a model from the net.
This was a 400000 poly Battlestar Galactica model, which unfortunately crashed the exporter (using too much memory).
I tried cutting this down repeatedly and got down to 42010 polies before I gave up on exporting the model. At this count the exporter didn't give me the out of memory message, but it seemed to hang and not do anything for 5 minutes so I stopped it.

So I made a box and ramped up its segments to leave me with a 10812 poly cuboid, this exported perfectly fine. The box was one single mesh with one single shader applied.
I got the model ingame and set about building alot of them. Initially it seemed to be fine, but when I got around 25 of the units there was a bit of noticeable slowdown as I scrolled past the units.

These tests weren't exactly scientific (I've no need to be making around 10000 poly models so I didn't want to test further) but the basic answer seems to be that somewhere between 6000 and 10000 polies the game starts to suffer from slowdown on my system. Somewhere between 10000 and 40000 polies the exporter starts to struggle on my system.

I'm running an Athlon 2.3ghz dual core, Radeon x1950 Pro and 2GB RAM.

My poly counts are in triangles, not polygons, and counted using 3dsmax. I have excluded bones and upgrades and only counted one set of treads (which are cloned for animation purposes and only shown ingame one at a time) where applicable.

[killakanz]

It's the chunks theory.

The sage engine renders geometry by giving each object it's own "chunk" or draw call. So it takes about the same processing power to render an object weighing 100 polys as an object weighing 1000.
It's the number of draw calls that have an effect on performance, so it's best to have fewer more detailed meshes than more low detail meshes. Just watch out for the vertex count, try not to let that go higher than it really has to for the object. Some Generals objects ended up with loads of separate meshes and massive overall vertex counts, what you should aim for is something like 10 meshes or less. The predator is made of 9 meshes, each object being it's own bone. The Mammoth on the other hand is set up differently. Using the same method as the predator, it would have too many chunks, so they've made the body all one object and used the WWskin to allow bones to control turret and barrel movement.
FACT: The mammoth has just 7 chunks. That's 2 fewer than the Predator.

All will be explained in more detail in a coming tutorial

Edited by killakanz, 04 October 2007 - 04:00 PM.

[Boomerang Python]

give it to us! gives its now!

[spyVspy]

I've been curious what counts as a chunk. If I have 2 bodies with vertices welded together, and I attach them in Max without welding any vertices, is that one chunk now? or still two?

[Mastermind]

Running W3X Viewer should give a number of draw calls, which you can use to see how many chunks it is using.

[killakanz]

I've been curious what counts as a chunk. If I have 2 bodies with vertices welded together, and I attach them in Max without welding any vertices, is that one chunk now? or still two?

Yes.
When you attach two objects together, it becomes one object. An object is simply a group of vertecies, some of which may be linked with a face, so yea attaching without a weld should still result in one chunk...

[Henford]

I have definately noticed this too, as I have been importing models with up around the 2000 poly count, and spamming them with no real hit on performance. This is great news, as it allows us all to be much more creative with our models, as long as we keep them all in chunks.

I would really like to learn how to use the WWSkin object for my meshes, as it seems the way to go for maximum performance.

[killakanz]

again, it will be explained in my tutorial. I'm writing it as fast as I can.

[Boomerang Python]

Are your fingers bleeding? No? Then it's not fast enough!

[killakanz]

There's still a few things I need to lay out. Doing this all alone again, it takes time.

[Mighty BOB!]

We have confidence in you.