Corner Alignment

How do you master builders out there deal with corners? I'm using the smallest size walls I can (.010) and have a dark texture on one side and a light texture (with an alpha channel) on the other.

After hours of adjustment by the tiniest increments, I still cannot get clean corners that don't have that flickering. The only way seems to be to leave a tiny sliver of open space between my two prims that are meeting up. I've tried everything from putting an alpha texture on the sides of the prims to making them black.

Do I need to make my walls thicker so I can hide the overlap? I had them at .100 but that didn't seem to help.

There has to be a trick to this....

Much thanks

try applying a transparent texture to the inner surfaces that you aren't meant to see.

Lets say you have a 10m square base and you want non-overlapping walls. If you want walls .25m thick, then your walls would be 9.75m wide. You corners are like looking at a joint like this: |_. That joint is rotated around to each corner. The butt of one wall will go against the face of the next.

The Patented Lordfly Method (tm) is to just put a "support beam" at the place where the walls intersect. The building looks sturdier, and you don't have to worry about texture flicker.

Thanks everyone

I have used the patented LF technique on other builds, but this was to be a low prim house so "cover and run" wasn't really an option since it would add upwards of 10 additional prims (which is a nice couch for someone on a 512 parcel.)

I was able to use the Noel's suggestion to reduce most of it but the wall seams are still a little flickery because you can either adjust for the dark texture on the outside or the light texture on the inside. So far, it seems like it has to be a custom solution on a case by case basis - not a global "all unseen edge faces set to transparent."

One option is to use hollow, cut cubes as your corners. Each corner will be one piece instead of 2, so gaps are impossible. Here's how to do it:

Cut a cube from .625 to .875, and it will have square edges. Then hollow it to match the thickness of your walls. Keep in mind, you're cutting away half the prim on each side, so each corner piece will have a maximum width of 5 meters on each side.

If you're making a 20x20 building, you'd end up using 8 prims, the same amount as if you were building the traditional way, but you'll have no seams at the corners. Each of your four corner pieces would be 10x10, which would give you a practical size of 5x5 after the cuts. Then you'd place a 10M wide wall piece inbetween each 2 corner pieces.

By the way, if the corner pieces and up too small for you with that much cut away, you can make them bigger by only cutting from .25 to .75. Just be aware you'll ned up with beveled edges on the inside. This is not generally a problem, as you can usually hide it pretty well, as long as you're careful with your texturing.

Another technique I've been experimenting with... takes some fiddling to make it look natural, though, so your mileage may vary.

Essentially, instead of making a 10x10 room, make it 9x10, or even 8x10. Then have one set of walls cover the other ones with a bit of an extension. It probably would work best on modernist builds, concrete and the like.

I'm still working on the details.

I don't like hollowed cubes for walls because they tend to grab the camera.

you'll see flicker if the prim faces are at the same spot, but you can remove flicker with a difference of only 0.002. You simply have to pick which prim is going to present the texture the viewer sees.

I tend to either use the "|_" technique Noel mentioned or I bring in one of the walls 0.002 (or 0.004 if it needs to tuck in on both sides) (if on only one edge, make sure this doesn't bust your by-the-numbers seam on the other end of of that prim).

If the short edge of a wall is showing, then just set the repeats of the texture appropriately (ie keep your ratios consistent). For example, if you are repeating a texture 1x horizontally on a 10m wide prim, then you'd repeat it 0.05x horizontally on a 0.5m wide prim.

I've noticed that hollowed round prims like cylinders and spheres do cause camera control problems, but I've never had an issue with hollow cubes doing that. I thought all this time it was a bug specific to round prims. Are other people really having the same problem with cubes? I build with hollow cubes constantly (huge prim-saver) and I've never heard anyone say anything. I'd really like to know if anyone else is having an experience similar to Forseti's.

I do use them occassionaly when I am building towers. Other than that, I normally avoid hollow boxes for a couple of reasons. Ten meters is not a lot of room for the camera even if the hollow doesn't "grab" the camera. Plus, its difficult to get a useful cut out of hollow boxes. The .50 is a clean diagnal cut that has to have the edges hidden inside another prim to avoid z-fighting or to hide the gap. Unless you want that look of that specific angle. Plus, how many prims does it normally save: one?

erm, what about making the inside surface of the wall slightly smaller than the outside. rotate a cube such that the top (z) surface is now the inside wall, then reduce the top x size (or top y size if you rotated about the y-axis). I don't know if you'll be able to get a small enough change in top size (especially if your walls are 0.01m thick) but it's an idea.

just my 2pence,

nand

Another thing...

I'd really not build walls that were only .01 thick. If you do need to do the thicker/thinner wall alignment trick, you can only go up, and that might get clumsy.

Also, .01m thick objects make the physics engine cry, or sometimes not work at all. If someone's flying fast enough they can plow through your wall.

I generally build walls .25m thick at least, with variably thicker walls after that to add texture.

Thanks for responding, but I'm not following you here. We're talking about cubes that have been hollowed and cut to be placed in corners. The 10M size is irrelevant since the walls inbetween the corners can be any width you want. So what exactly do you mean?


As I said earlier, if you cut from .625 to .875, you get square edges, not diagonals. If you do go with diagonals though, they're easy to hid if the texturing is right. Assuming the build is well textured, the only time the diagonals become obvious is when you look at where they meet the floor, and that can be hidden with furniture, or minimized with good floor texturing.


It saves a lot more than than you seem to think. Using the method properly, you can cut your prim counts by as much as 50%. Let me explain.

First and most obviously, it saves one prim per corner, not one prim per build. If you're making a 20x20x10 rectanglular building, you can do it with just 4 prims instead of 8 (assuming you don't mind the little v-cut where the prims meet, which as I said, is easy to hide with texturing). Over the height of a large building, that really ads up. Let's say you extend the same structure to a height of 50M. You just saved 32 prims. For someone on a 512M plot, that's more than a quater of their total allotment. That's huge.

Now think about more complex structures with lots of corners. The savings are enormous.

Second, it saves an incredible amount when you're doing an angled structure. Let's say you want to build a sloped wall. Using hollowed and cut cubes, you only need one for every 10M of height, but using regular cubes, you need one for every 10M of hypotenuse, which drives up the total cost considerably. The following chart shows how many hollowed and cut cubes (HCC) you'd need vs. how many regular cubes (RC) for a 45-degree sloped wall, 10 meters wide.

Height     Hypotenuse     HCC's Needed  vs.  RC's Needed
 10M          14.14M           1                   2
 20M          28.28M           2                   3
 30M          42.43M           3                   5
 40M          56.57M           4                   6
 50M          70.71M           5                   8
 60M          84.85M           6                   9
 70M          98.99M           7                  10
 80M         113.14M           8                  12
 90M         127.28M           9                  13
100M        141.42M           10                  15

As you can see, the savings are quite substantial using hollowed and cut cubes. Keep in mind, the numbers in the chart are just for 10M of width. Apply this to a fairly wide wall or to a build with many such walls, like a pyramid or a postmodern building, and you can see the savings are gigantic.

For a quick example, one of my first builds in SL was an 800,000 cubic meter glass pyramid in Argent. It's long since gone now, but while it lasted it was 100x100x80. The corner pieces were cut in half, and the wall pieces were cut by 3/4. Obviously, this gave this the interior a lot of v-grooves where the pieces met, but that wasn't a bad thing at all. The grooves made nice window frames. Anyway, the important part is had I been using regular cubes instead of ones that were hollowed and cut, I would have had to increase the prim count by about 30%.

The same is true, by the way, for my current home, the Sci Fi Museum in Indigo. If anyone hasn't seen it, it's a full size repica of Starfleet Academy from Star Trek TNG. The building is rather large, roughly 100x40x50, and it has many twists, turns, slopes, and curves. Had I not incorporated hollows and cuts into the design, I'd estimate it would be about 15-20% prim heavier than it is right now, and it's already much heavier than I'd like it to be.

Anyway, since I do use this technique so much, as I said earlier I am very curious to hear if anyone is having camera problems with it.

chosen,
I really noticed this hollowed-box camera problem in the early version of midnight city -- the brownstones were using a single hollowed box prim to create a 10mx10m room (slight cut for a door I think). And man oh man, did that play havoc with the camera when you tried to zoom in on something on the wall.

i'm intrigued now... gonna test this later at various levels of "cut" and camera movements.

(btw, my name is mispelled in your sig LOL)

Thanks for the reply, Forseti. Now that you mention it, I do seem to recall having camera issues with hollowed cubes that are uncut, but never with cuts. I haven't played with uncut ones in a while, mainly because I haven't built any structures as small as 10x10 in a long time. Like you, I'll experiment and see what I find. Perhaps we can compare notes.

And thanks for the heads up on the sig. I'll change it right away.