Buildings "going transparent" at joins

Hello, Building Gurus

I'm rubbish at building, but have finally decided to learn more about it .... I guess there must be a thread somewhere on this very topic, but I can't find it :/ sorry.

I thought you could stop that annoying business, where hollowed prims look transparent as soon as you get close to them, by making the walls thicker.

However, I've just been making a tower - here, if you're interested: http://slurl.com/secondlife/Maeshil/94/124/63/, and can't find any way to allow avatar access to it ....

It was meant to be simply 2 prims. I thought I'd use hollow cylinders, and nearly killed myself creating the textures for it! As it turned out I couldn't use hollowed prims because, however small the hollow, the place where the 2 cylinders joined did that 'visible plane' thing

So I made it solid, and tried various ideas around a phantom/hollowed/ring-shaped prim in the top, so users could at least stand on top & look over the parapets.
Same thing happened.

I never see this phenomenon in high-end commercial buildings, so there must be some correct way of dealing with it!

Please, please, can you point me towards the solution?!

Thank you
Cherry

You can use a transparent texture on the hidden faces so they don't show up.

You can also line the two cylinders with identical x, y positions and separate the two by exactly 10m, assuming each one is 10 M high.

To enter, you could cut one cylinder enough to allow entry. That could be another cylinder with a z dimension of 3 to 5 M.

Hi Cherry,

I have quite successfully made a round tower using hollowed prims. Made a lighthouse, in fact, two stories tall. It can be done, and I'll be happy to share the "tricks".

1: It sounds like the biggest problem is that you are using a 32-bit alpha masked texture on both the inside and the outside of the tower. That is going to cause sorting glitches. Same goes for using a 32-bit texture on both the inside and outside of a sphere. In a simple case, imagine a lampshade. Just a hollow cylindrical shape. But it will look screwy if it's translucent from both sides.

The solution here is to use 32-bit textures only on one of the inside and outside surfaces. I would suggest saving your 32-bit alpha-mapped version for the inside, so you can look out, and use a 24-bit non-transparent texture on the outside, perhaps with curtains closed on the windows.

2: Edge sorting. Same issue if you apply a 32-bit texture, even a 100% transparent one, to the edges where the two cylanders join. Don't. Apply a solid 24-bit texture or the default "blank" texture, and tint it so it's a close match with the exterior, just in case the seam isn't perfect. This will eliminate sorting glitches on the seam.

3: Getting inside... Use a cut cylander for the bottom level, so you have an opening for a door. Add one more prim across that opening, textured as your door, and either script it as an actual functioning door that swings open, or make it phantom and NOT linked to the tower. (Phantom primscan't be linked to non-phantom prims).

Now for the bad news...

A hollowed prim will cause problems for you, if you try to focus your camera at the inside wall while inside the space. Your camera will end up behind the intended position, same line of sight, but outside the prim.

When I made my nice round lighthouse, in order to make the inside a usable space, I had to line the walls with flat prims. So it was nice and round outside, but on the inside it had flat faces. And that meant a much higher prim count.

IM me in-world, perhaps this Friday evening, and I will be happy to rez that lighthouse for you to examine. It isn't in-world at the moment, as I took it down to fit a larger home on that parcel.

OMG, that's great advice - thanks!!

Just altering the textures, so alpha was only used on the outside, made a massive difference!
I had no idea .... I can see that this is going to involve using extra prims: suddenly I see why builders use window prims!!

Thank you so much

Does anyone know why my Z indices never seem to match up? I mean, positioning a 10-metre prim on top of another one at Z co-ordinate 62 does not result in a poistion of 72. It always seems to be almost half a metre less.

Ceera, I would love to see your lighthouse & will try to catch you in-world

Thanks again,
Cherry.