Flickering holes in my dungeon tile textures

[syscrusher]

I've built a new Ayleid ruin tile that I needed for my mod; it's a spiral staircase that is much smaller and steeper than the vanilla tile, and which mates with the vanilla "narrow hall" tiles.

After a lot of tribulations, including learning to vertex paint in Blender (which I had not tried before), I have a working mesh with valid collision. In Blender and in NIFskope, it looks fine, but in the CS and in the game it has holes in the textures that shift and flicker as you move. The effect is very much like the aliasing effect when two pieces of geometry exactly overlay one another, except here there is only one object.

I have checked carefully in Blender and can rule out doubled geometry; in any case, the symptom is that you can see through, not that you see something else beneath.

I have a theory that I may have done something subtly wrong with my collision object, causing it to attempt to render as a visible but fully transparent surface, but I can't prove that yet. I am going to temporarily remove the collision to test this theory, though. UPDATE: I used NIFskope to completely delete the collision mesh, and the problem continues, although of course my test character now falls through the floor.

I have posted screen shots of the problem in my personal gallery on TESA.

Any guidance would be much appreciated. Thanks!

Edited November 3, 2011 by syscrusher

[Hanaisse]

Ok, at first it looked like dup meshes.

Have you made sure to delete all the material properties on the collision?

[WindmillTilter]

The pics sure look like overlapping faces. If you're positive you've ruled that out I'd suggest posting the mesh so we can have a look.

WT

[syscrusher]

Ok, at first it looked like dup meshes.

Have you made sure to delete all the material properties on the collision?

I agree...that's exactly what it looked like to me, a normal mesh duplicating a transparent mesh.

I not only deleted the material props on the collision, but in fact tested by temporarily deleting the bhkCollisionObject entirely, using NIFskope. (This way, I could be sure that my newbie status in Blender wasn't causing me to *think* I deleted the collision mesh.)

I wonder if I have an extra "draw type" on the base visual object, though...that is something I had not yet checked, and will do so.

[syscrusher]

I wonder if I have an extra "draw type" on the base visual object, though...that is something I had not yet checked, and will do so.

Nope. I also deleted a test object that I had in the Blender file, but which I wasn't exporting, to see if that was the problem. No change.

By the way, I apologize for posting this in the Study Hall thread. That was a link-clicking mistake on my part from the forum menus; I meant to put this in the general TES IV modding help forum.

I'll be glad to upload the mesh; what's the "right" way to do that on this board? It would be just the mesh, no textures, because the object uses only vanilla textures.

Thanks to those posting.

[WindmillTilter]

I'll be glad to upload the mesh; what's the "right" way to do that on this board? It would be just the mesh, no textures, because the object uses only vanilla textures.Thanks to those posting.

Click on the Use Full Editor button when you reply, then click on the Click To Attach Files button at the lower left.

WT

[syscrusher]

Click on the Use Full Editor button when you reply, then click on the Click To Attach Files button at the lower left.

WT

I don't have such a button, as far as I can tell, just a lot of options for formatting. The lower buttons for me are Add Reply and Preview Post only. I suspect this may be a security privilege that my account lacks. I'll send you a PM with the file, and you're welcome to attach it here if your account allows.

[syscrusher]

Definitely no upload button for me in forums, but the button was in my PM full editor. PM sent.

[syscrusher]

Windmill Tilter helped me solve the problem, in a PM exchange. I'm asking permission to repost the helpful comments here to assist others in the future.

[syscrusher]

Following is the transcript from a PM between myself and Windmill Tilter, in which the problem is found. WT had almost the right diagnosis, and that suggestion sent me in the right direction. Reposted by permission of Windmill Tilter, in case others run into the same problem.

Looks like it was overlapping geometry. You have two copies of what looks like your collision mesh exported in the NIF. Blocks 8 and 10 are the culprits and removing them seems to solve the problem. Unfortunately I don't have Blender installed so I can't look at the scene your exporting from. I'm fairly positive it's your collision geometry though as they are both a single NiTriStrips that cover your entire geometry (as opposed to the 3 pieces of physical geometry required by the 3 different textures), and they have no material or texture properties.

Correct on the blocks, and that was in fact the problem. It wasn't the collision, though. What happened is that I had two copies of my *visible* geometry from when I was making the collision mesh, but they were set to render as if they were collision. You sent me in the right direction!

Even knowing the nature of the problem, I still couldn't get that geometry to select for deletion in Blender without also zapping good geometry. What I *think* may have happened is that I may have parented a Blender node to itself. Oops.

I finally ended up deleting the extraneous parts in NIFskope and then re-importing the result (after testing it in-game) back into Blender to rebuild my .blend file from a known good source.

I haven't tried the updated mesh ingame, but I dropped it in the CS and it looks good. On a side note your collision geometry is pretty high poly. If your not using too many instances of the staircase I wouldn't bother redoing it, but in future you could save on performance ingame if you use a lower poly mesh as the base for your collision. It's time consuming to have to model a low poly version, so if your not seeing any performance issues it may not be worth worrying about, but it's something I do personally.

I had intended to optimize after getting the thing working at a basic level. The collision mesh you received was literally just a copy of the full visible mesh, at full poly count, set to render as a bounds object. Once I got it reimported, I went back and did some poly reduction.

What I'm observing in-game is that I can reliably get about 75 FPS running in a *virtual machine*, an environment in which an empty test cell only gives me about 80 FPS. The 75 FPS was achieved with the object in my actual dungeon cell, with other geometry (but not much clutter) around. As you point out, there probably won't be many instances of a spiral staircase in one cell, so I'm not going to worry about it excessively.

Thanks very much for your assistance! I had tried nuking the collision mesh, thinking that might be the problem, and had looked for double geometry. What I didn't anticipate, until your comments led me there, was that I had an invisible copy of my visible geometry. Ugh!

If you don't mind, I'd like permission to post this message (including your quotes above) onto the end of the public thread, in case others run into the same problem.

Syscrusher