Building by the numbers but there are still seams

Hello. I'm building some furniture. I use numbers and a good deal of math, everything is supposed to be aligned perfectly, but there are still seams showing when the camera is at particular angles or from a particular distance.



Is this something that cannot be avoided? Are there any ways to compensate for this (e.g., with the use of particular textures)? When I zoom in close to these problem areas, it looks like the prim edges are off by less than 0.001 m (the SL minimum). I know this because, when I try to change the position of a problem prim by 0.001, it either overlaps the prim next to it or leaves a gap between them. I can never manage to position it exactly next to it. It's as if some prims, upon creation, acquire coordinates with more than 3 decimal places (e.g., z=700.2565) and this can never be changed afterwards.

Seams are pretty much impossible to get rid of entirely, and shiny makes it more obvious that they're there. Do they only show up at certain distances? If so it could be different LOD (level of detail) models for the different prims messing it up.

Does it look like that immediately, or after some time? There's this thing called prim drift, sometimes over time the position floats "drift".

Another possibility - the precision for positions and scales is more like 5 decimal places rather than 3. You can't get at that precision in the edit box, but you can get it via scripting.

Also check your rotations are really accurate. A tiny error in the rotations can look like an error in positions when it turns up in seams.

Thanks for answering. I believe it's the third possibility you mentioned. These seams appear up close too. It's more about the angle of the camera and how these gaps are lighted by the sun. So I don't think it's LOD. Also they appear immediately (not prim drift) and the rotations are all precise too (there are no 89.95s, etc.). I would like to learn more about that scripting method if anyone knows more about it and if it's not too difficult to figure out (no programming experience here).

Here's a little script that you can use to make very precise movements:

default
{
    touch_start(integer total_number)
    {
        llSetPos((vector)llGetObjectDesc());
    }
}

Put this in a prim, and edit the object description to look like:

<166.764, 204.196, 25.887>

(or whatever the actual object position is). You can edit the numbers to 5 decimal places. When you touch the prim, it moves it to the position written in the description.

Wow. Thanks. I'm glad I asked for help. This looks simple. I suppose that, after I use this script, I can just delete it and the position will remain unchanged, correct?

Emily --

Even when the prims are aligned exactly to the numbers, it will be very difficult to get rid of these seams.

What you are seeing is a glimpse of the hidden (abutting) edge of each prim. Since the hidden edge is perpendicular, it is lit differently (darker or lighter). One first step can be to make the hidden edges alpha-transparent.

Now, unfortunately, you will see occasional glimpses of whatever is behind the seam. To fix this, I have occasionally put a parallel prim (like a piece of tape) just behind the seam. The surface must be parallel to the surfaces you are trying to blend, so that it is always lit in the same way.

For me, this is the most annoying consequence of the ten-meter prim limit. It's fine to say use two prims, but everybody can see where the seam is! Oh, and hardware lighting will actually light the exposed surfaces of the prims in such a way that you can often see where the triangles start and end at night.

I made a twenty-meter hemispherical dome out of trapezoids using this technique. It turns out that top-sizing doesn't have comparable resolution to the sizing and positioning controls, so that the seams were invariably wider at the top or bottom and some kind of tape was necessary.

Can someone explain to me again why it's a good thing that I just can't rez a twenty-meter sphere?

--Allie

Almarea, thanks. I will try this too. If this script still leaves tiny seams, I will use an alpha texture for the hidden edges and a prim that is parallel to the visible edges and runs right under them and across the seam (if I understood correctly). Sounds like this combination of methods should do the trick.

It's actually more than five in the low-value end of the sim (e.g. the west side for the X coordinate) and a bit less than five in the high-value end (and you may find your five-decimal number rounded up or down by one).

Floating point numbers.

So, prefer north-easterly property for the best building conditions!

By the way, even positioning them to five decimal places isn't going to get rid of the sparkles.

--Allie

Good luck. Let us see the results!

Thanks

Yes. Just be careful not to typo - a wrong number and it'll move it somewhere else. The maximum that llSetPos moves a prim in one call is 10m though, so it won't zoom halfway across the sim if you make a mistake.

Ok, I will. Thanks again