Reflections

I was walking around and saw a reflection...

I was walking around and saw a reflection...

This gave me pause for a moment. Because I have water reflections turned off, and because the water level in this sim is far, far below the ground. So I started moving my camera around, trying to figure out how this was done…

And this is what I found...

And this is what I found...

The entire scene was mirrored and duplicated on the other side of the floor prim. 🙂 Horribly inefficient, but striking all the same.

Take a look.

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One prim clock, revisited

I have more or less dropped my attempts at making a single-prim analog clock, until I have abruptly bumped into a solution, used expressly for this purpose in the Japanese lands. All credit for this trick goes to kit Pizzicato, who sells them under the label *chronokit* — whether the original inventor of the trick is the maker of the clock, I don’t know, but, I’ve figured out how they did it and am going to tell anyone who cares, now. 🙂

To the left is the original, my replica of the prim is to the right.

To the left is the original, my replica of the prim is to the right.

The mystery shape is a Ring type prim, with around 75.0 hollow, Triangle hollow shape, and a 0.25-0.75 profile cut. Chopping a ring up like that results in a round object with at least three individually texturable faces visible from one direction, depending on other parameters — the limit you can twist it into would be five. By default, the texture on these faces is distorted in a non-linear fashion. However, if you switch the texture mapping to planar, on at least three of the faces the distortion will become linear, and you can use a rotated flat texture to create a clock face and a minutes and seconds hand with no unusual scripting required.

No, really THE tallest standing structure

After I wrote that post about the tallest towers in Second Life, I thought I wouldn’t need to return to the subject, until I bumped into what has to be the tallest tower currently standing in Second Life — literally bumped, I was trying to fly a plane. Surprisingly, it’s built on mainland, which would otherwise make constructing such a structure impossible, if it were not for supergiant megaprims up to 256 meters in one direction, that have recently become available. The sky platform at the top is 4000 meters up, which is pretty close to the current build limit of 4096. But they weren’t satisfied with that and put up a particle beam shining all the way into the void above, no idea how far that goes.

I must mention that a thing like Salt HUD, as well as related HUD tools, makes searching for the right megaprim size and orientation a breeze, and allowed me to get rid of all those open boxes in my inventory, knocking the total at least 1300 items down, which can’t be bad for the poor asset server. 🙂

KB Labs Tower

Not very detailed, but you've got to admire the effort

There is also one more replica supertall landmark built in Second Life that I missed in that list, namely, the ghostly World Trade Center towers memorial. They are rather finely detailed for ghostly boxes, and are built exactly to scale, but commercial development right across the street kind of makes the whole idea dubious.

Please ignore the open shops behind my back.

Please ignore the open shops behind my back.

Prim torture

I’ve been trying to make a single-prim analog clock.

There are numerous ways an analog clock can be made in Second Life. So far, the ones I have seen included two different approaches..

The first approach is the obvious one — you create a primitive for each clock hand, and rotate them over the clock face. This looks good, but results in three prims at the very least, and often, quite a bit more for added detail, or at least for the seconds hand.

The second approach layers three minimal thickness boxes upon each other, using the front face of each to display a rotating texture.

While it is obviously impossible to create a single prim clock using the first approach, I’ve been thinking of ways to get more than one texture visible overlaid on the same side of an object. After many unsuccessful experiments with spheres, I have been able to get two textures on one side of a cube, actually:

Pretty trivial once you think of it.

Pretty trivial once you think of it.

While the inside of the hollow cube is counted as a single prim “face”, and is therefore distorted by stretching the texture across four faces that we see, it is distorted in a linear fashion, easy to compensate for by texture repeat settings while still drawing a texture as if it was perfectly flat and not distorted. If the face you see from the side of that hollow cube is transparent, you see the part of the inside face that is furthest away from you, or, to be technical, you see the part of it that has the polygon normals pointing towards the camera and don’t see the part that has the normals pointing away from camera. Squish the cube flat in that direction, and you’ve got an almost flat sheet with two overlaid textures which can be manipulated separately.

There are multiple things this could be used for beside a clock face, for example, for crossfading two arbitrary textures, or assembling fabric patterns from separately tinted textures.

Unfortunately this will only bring the minimal clock primitive count down by one, since you still need another texture for the clock face. I keep hoping there’s some way to do it similar to the technique to get a prim with five separate “faces” side by side, as used commonly for billboards of various ilk, however, it does not seem to be possible without some high wizardry I do not yet know.

Low prim home improvement

I’ve been messing around with my skybox for the past few days, trying to make it presentable on a very low prim budget. Since it was so low, the standard 117 primitives of a 512 square meters plot that comes with a normal paid account, it involved not only picking extremely low prim furniture, but also, wracking my head trying to find clever tricks to save a few more primitives. Here’s some of the tips I managed to accumulate along the way:

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