Having problems with Prim Alignment...

I just the same as most others, can be really picky about how my prims line up when I am building. I never noticed it till recently but during a large build, like aligning 2 10x10 prims for instance. Normally I could use the built in grid and just snap them together and it would be done. Now it doesn't seem to work that way though... I can snap them together but when zooming in onto them really closely I can see they arent lined up by 1 or 2 pixels in a certain direction. To remedy this, I tried to use the numeric position settings and adjust them .001 at a time to align them. This however doesnt work, because it seems that the prims end up 95% of the time off of alignment by .0005 roughly. Problem is the build too doesn't let you adjust by anymore than .000... So I have ended up spending at least 2 hours or more trying to align just a single pair of prims and end up failing... So I ask, does anyone have any tricks they use to force prims to line up perfectly?

I have seen builders tools but being I am working with prims so large I really doubt that the tools will work correctly. Does anyone have any ideas on how to get these to snap together better? I have heard of "snap scripts" but I haven't been able to find them anywhere.

-Miles

If I'm working with different prims and I can't get them to line up I verify a couple of things:

First i make sure they are all at the proper coordinates (if lining up 10x10 blocks I'll take coord y + 10, etc. and manually set them if needed).

Second I look at the thickness of all prims on a plane I am manipulating and make sure they are the same thickness. Just because you align them on the same Z coordinates doesn't mean anything unless the prims are the same thickness. Recently I had to go through one of my buildings and spend an hour plus cleaning up all the chunks because I had some tiles that were like 2.90m thick and some that were 2.93m thick or something like that (who knows how it happened).

I'm finding that as I build more and more objects I'm using the manual alignment method using typed coordinates vs. the grid more and more. Using the grid is great when I'm whipping something movable out but it is a huge pain when I build some structure then find out that the z coordinates are all whacked out for some unknown reason.

One other thing I've found is that some objects will never quite line up correctly, like when you are hooking some circles to squares. You can get it at like 99% but without manipulating numbers and experimenting manually sometimes it never really looks right, and even after you get it as good as you can it still isn't perfect but close enough so that most of the time no one will notice.

I found that the grid "does" work to some extent, my problem is AFTER I move them... So if you line them up, link them, then move them somewhere else... they seem to un align themselves... so i ended up making my project a permanent piece, and locking it it where it was built... i haven't tried moving it yet... took me 2 hours to finish. Thanks for your reply though, I think I got it sorted out for now, but I am going to look into some snap scripts for large objects for future projects.

This is something I noticed too, I can build a house on a spot without any gaps. However, once I link the house, move it around or rotate it (especially after a rotation), gaps start appearing between the seams. This happens even for right angle rotations (90, 180, 270 degree rotations). Even if edit single part, or unlink the entire house and manually correct their positions, these gaps will still remain.

I am beginning to be convinced that the Secondlife programmers lack even a fundamental knowledge of mathematics... I'm beginning to think they may have jsut bought some engine SDK and have been steady fucking it up ever since....

This is a rounding off error mostly affecting maximum sized prims (10x10 cubes). Its commonly referred to as 'prim drift'. Its been reported many times over, but so far, nothing has been done to rectify it.

Its been around since a very long time, and got more serious about half a year ago.

It can sometimes be corrected by rekeying in all the figures in the edit panel, expecially rotation. For example, just because it says there 270 degrees, doesn't mean its 270 degrees.

Some of us got over it by simply just not caring so much about precision.

Try Skidz Partz on Explorers Rangeland (29,16 for snap together prims!

I cant do that man... just cant.. I am involved IRL game development and seeing a nice house with misaligned prims drives me absolutely bonkers. maybe its just me... I cant stand the noobish look of HOM effects or overlapping prims.

If you're still seeing some "flashing" of textures when looking at seams and you know that they are aligned properly (by the numbers)
then try this:

Get a totally clear texture and change all your prims to totally clear.....not just the surfaces that can be seen. (For large builds, it might be easier to do in sections...I tend to only link a few prims at a time while texturing and then go back and tweak them after they are all linked)
Edit the prim or if they're linked already, then edit the linkset and select "edit texture" .....click on each SURFACE that is visible while holding down the shift key.
Once done , you can change all the "viewable" surfaces to the texture that you want while leaving the edges of the seam totally clear.

This will get rid of the flashing of seams.

Further on Markubis's idea - and I can confirm this works.. It was recommended to me to try setting the adjoining surfaces transparent.. this diminished the problem but did not eliminate it. So again, once you KNOW the numbers are correct, and I am in the habit of doing the math and plugging in the numbers, I tend to paint the adjoining surfaces a flat black with the default plywood texture, no transparency, and as long as the textures you apply to the visible surfaces are relatively low in luminance, you should not see any seams from any angle. I generally accomplish this by painting the entire object black, then going back and retexturing/coloring the visible surfaces. The Skidz Primz product is indeed an ingenious tool, and very useful for serious builders, however I think what we are looking at here is either a flaw in some basic geometry on the server side, or a rendering flaw in the viewer.. and math is math after all, whether it's a script doing it or the windows calculator..

Horrible, just horrible. I bought a little house, rezzed it, changed colours, rotated, took a copy, rezzed it again, rotated some more, and now I have faced some real bad drifting. Maybe the house was not even exact in the first place, but hand crafted. I guess I have some granite rock wall here through which I have to walk in order to get my house look ok. And the house just has not become drifted, but it drifts _in real time_, if I rotate my viewing point.

Like I have a corner pole of the house corner and a horizontal plank attached to it. If I look the pole directly from top of it and rotate viewing, the plank seems to be attached inside in middle of the pole. But if I give some angle to the viewing and then rotate the viewing point, it looks like the plank is drifting from the middle of the pole to left and back to right in real time when I move the viewing point.

Also many parts of the house flap behind or front of other parts when walking around. Like I have a pole which goes behind a box. But if I walk around, the end of the pole pops up into front, where it should not be. This is so bad, that if I put a plant near the corner of my house, it looks like the plant gets suddenly crunshed between and inside the tiles of the house when I walk by.

So many places of the house seems to pop up or flicker when I walk around. Quite a robust house with no seams where sun shines in, but I really must do something about the flickering and plant eating.

Kratax

The flickering and plant eating are probably caused by the opengl display ordering bug where alpha channel textures interfere with each other.

You would have this problem if your windows are drawn as part of the wall. Different wall sections will interfere with each other. Putting plants in front of separate windows will also cause this. This effect can displace some surfaces by up to a couple of meters.

Every texture that does not require transparency should be made from 24 bit tga files. Only use 32 bit files where you really need the transparency effect.

Ed

ed44,

Thank you for the info. If this advice is not in the tutorials, it would be a good idea to put it up there. I hope OpenGL will be fixed.

I really have a house that has corner poles and planks framing huge windows. So it would be better to have windows as separate objects and not part of the house. But you say that won't help with the plants. I guess I'm doomed. I will have to do some serious rebuilding to my house where I adjust everything from textures to positions. Luckily its not too big a house, though it uses lots of transparency.

I have a water fountain with water texture and a block of granite. The block is totally above the water, but in some viewing angles the water flickers above the block. I noticed that the block was made as a combination of two odd shaped blocks and I replaced them with two better shaped blocks. Now the water does not flicker above the block. Wierd, but saves a little bit of my day.

I just wish, but it would be great if graphics behaved realistically in SL. Like if I have two blocks of black tiles which have their sides colored white, then in real life that white would not show up as bright dots from the seam between the blocks. In real life there might be some dark shadow surrounding dark grey color that could not be noticed - not bright white dots. The same goes the other way around. If I have two white blocks of tile and their sides are black, then in the real life the black would not show up as deep pitch black dotted line from the seam but as some unnoticeable dark grey edge.

I second this recommendation. I am totally hooked on Skidz Primz for aligning my prims. Now I wish there was a similar tool for aligning sims that aren't meant to touch...say two or more prims that are on the same plane. I can always use math, of course, but having a tool would be awesome.

selma