Double Sided Triangles

[DKealt]

Hey all,

I've been hunting around for answers in regards to the mentioned "Double Sided Triangles" in the Nif _vox Debug files.

As far as I'm aware they tend to cause lag and corrupt damaging ingame.

Does anyone know what they are and how to solve the issue to at least some extent.

[X_TheUnknown_X]

I've had a few 'dealings' with double-sided triangles in my short time here modding for BC.

The first thing I can suggest is to check your ship model for duplicate faces and 'unwelded verts', if possible. That, I believe, can sometimes be the cause.
The other problem I found when making a space station, is how the damage resolution is set up in the ship hardpoint and/or the ship script file. For the station, the value was too high, or too low in the ship script; I don't remember which.

Ususally, a few double-sided tris here and there have no negative effects but too many does cause issues.

[DKealt]

I think I've sorted the unwelded vertices issue. I'm using Max and I hoghlight all the vertices and weld all of them within 0.1mm of each other.

I didn't know about the HP issue though. Just out of curiosity how much is too high or low? 10 ... 1 ... 0.1? Also how does the damage resolution work should an Intrepid have half the value of a Galaxy because of the scale?

I have found the odd poly overlapping but I think I've got rid of most of them.

ATM there's around 200 DST's but considering the model is 70,000 polys it could be worse.

[limey BSc.]

Apply an STL Check on the model, then check "Check" down the bottom. That will check for for a wide array of mesh errors and highlight them on the model and you'll see a count down the bottom. Just keep eliminating errors till they're gone. You can narrow the check to certain kinds of errors with the other check boxes.

[DKealt]

Wow what a great tool didn't know about that one. OK result are in, there was one case of a multiple edge, so not that many.

The other thing it highlighted was "Open Edges". This one I'm npt sure about because essentially I did them on purpose.

Ie. I have a series of lets say Box shaped details running along the hull. I deleted the polys that where flush with each other, as in the bottom face of the detail so they didn't double up.

I had this idea that different elements shouldn't intersect as that might cause an error, am I right?

All the other models such as CG Sov are seperated at the saucer seems so in theory they would have hundreds of double edges

[limey BSc.]

The other thing it highlighted was "Open Edges". This one I'm npt sure about because essentially I did them on purpose.

Ie. I have a series of lets say Box shaped details running along the hull. I deleted the polys that where flush with each other, as in the bottom face of the detail so they didn't double up.

If you are going to have an ununified mesh, then yes, you will have lots of open edges. Doing that is a trade-off of polys (with one, admittedly extreme, test I did, I saved almost 20% of the polys by not unifying the mesh) for potential problems with damaging.

I had this idea that different elements shouldn't intersect as that might cause an error, am I right?

To be honest, I'm not entirely sure if that would help at all. As far as my knowledge of what causes the problem goes, that shouldn't actually solve it. Not sure though.

All the other models such as CG Sov are seperated at the saucer seems so in theory they would have hundreds of double edges

That's caused by the exporter. When material ID's are used on a fully unified mesh (to assign different materials to the same object on a mesh), the exporter has to seperate them into distinct groups, since BC can't handle multi-materials.

[DKealt]

Right okay, I'm attaching a few images to properly explain, but the advice is still very helpfull

This first Image is the complete model

"See Complete Model"

This second image is the main elements of the model the Body, Wings and Hull Plate. All of those are modelled as single meshes.

"See Main Model"

Thirdly there are the Details. All very minute and pretty much impossible to model to a single mesh and in the next image it shows how the elements have no rear poly to cap them off.

"See Complete Details"

"See Complete No Sides"

So in essence is it necessary to cap them off?

And from what you can see are there any more modelling tips on how to make it as stable as possible.

P.s. Thanks for the swift and helpful replies, this is my first Model so I'm being a bit of a n00b