Bethesda collision vs exported collision

[Deathless Aphrodite]

I've noticed Bethesda collision is integrated in a nif file with this structure:



while when I create a totally new collision mesh with 3dsmax 7 and export it with nifprops I get this structure:



The exported collision, although working, is always causing a huge hit to fps. This is not justified by the complexity of the collision mesh, because I've tried with simpler meshes but the hit is there too. So I guess it may be this difference, Bethesda's bhkpackednitristripsshape versus the plain bhknitristripsshape the exporter creates.

Is there no way to export collision with the structure used in Bethesda's collision objects? Or convert collision from one format to the other?

[shewter]

As of nifskope ver .9.7 you can pack the strips,right click on the
bhkNiTriStripsShape choose Havok---->Pack strips

[SACarrow]

Does packing the Havok strips improve performance? If so, that would be a big step forward.

Steve

[Deathless Aphrodite]

I will try that, my version is .9.5 so I didn't have this option. Thanks a lot for the info! I'll let you know how it goes performance-wise.

Ok, downloaded version .9.8, which is excellent, done the Pack Strips spell but the performance doesn't get better.

If I delete the collision mesh from the incriminated nif file, fps go from an average 15 to an average 30, not joking. 15 fps lost for a collision mesh...

[Razorwing]

I didn't know there was a new Nifskope out I'll go get it immediately, and experiment with the packing feature.

It's pretty fast to set up collision in Nifskope once you get used to it though. It's cumbersome at first but in most cases it's the best way to go, since the performance hit is so low. Still, it isn't immune to performance hits, which I noticed recently when I used fifty spere shapes in one of my interiors. You can get a lot of box shapes for the 'cost' of a sphere shape. The thing I like the most about creating collision in Nifskope is that it's futuresafe. Even if Bethesda releases an official exporter I won't need to remake or re-export that collision, because it's as optimized as it ever can be.

How many faces does your collision mesh have, Deathless Aphrodite? You really shouldn't use more than a hundred faces to steer clear of FPS problems.

[Deathless Aphrodite]

It has much more than 100, but I'm onto the process of optimizing.

When you talk about setting up collision in Nifskope so it is perfectly optimized, what do you mean?

Do you maybe know how to work MOPP shapes? That's what's missing in the exporter.

[Razorwing]

Originally posted by Deathless Aphrodite
When you talk about setting up collision in Nifskope so it is perfectly optimized, what do you mean?

I tried to get the hang of how to do it for a long time. It wasn't until I read the brilliant tutorial dding Collision Model - Step by Step Guide that I finally understood how it worked. The method I mentioned differ from the method in the tutorial, as the latter explains how to add a collision mesh created in a modelling program, but it's great at explaining how to manipulate the blocks. The http://cs.elderscrolls.com/constwiki/index.php/Finessing_Physics tutorial is great for reference too.

Originally posted by Deathless Aphrodite
Do you maybe know how to work MOPP shapes? That's what's missing in the exporter.

I've never investigated them and I don't know of any way to work with them, sorry.

[Deathless Aphrodite]

Thanks everybody. I've managed to optimize the nif and now there is no fps hit. Thanks for all your suggestions, the tutorials and such.

[Deathless Aphrodite]

While modding I noticed there are some Bethesda meshes where the default collision is not done well. For instance if you walk all over the deck of the pirate ship in the IC waterfront, you'll notice your character (in 3rd person) just seems to float at times because the collision mesh is misplaced.

I had to correct this too because my mod has a ship with crew.

[SACarrow]

Deathless Aphrodite: If I can ask, what was the ols collision face count versus the new?

Thanks,
Steve