Gap between prims.

I have two prims up against each other, but I can not get rid of a tiny gap. The relative positions of the two prims are 100% spot on by numbers, I've confirmed that neither prim is rotated, twisted, tapered, or sheared, and it's now driving me bats!

Any ideas?

This has been asked about a lot recently. Search the forums, I believe Chosen Few (It may have been someone else) gave a complete answer as to why it happens, based on antialiasing.

Also, try making sure the faces that touch have the same texture as the visible faces, and aren't brighter, diff colour, etc.

(EDIT) DOH--so you say they ARE lined up perfectly, but you're getting a shimmering line...hmmm. Bummer.

Try setting the facing textures to a 100% clear alpha texture.
I do know the issue you are describing and it is very 'unsettling".


~Maddy

Both prims have the same texture on every face, all faces have the same number of repeats m^-1, and both prims have the same mapping, shininess and bumpiness. I'll do a search on antialasing; thanks Okipha.

I tried that already, but no luck - it's definitely a physical gap, and not a texture effect. Thanks anyway!

Well it must have been some kind of bug! I just deleted one of the prims a replaced it with one with identical dimensions and coordinates, and problem solved!

Thanks for the replies.

Every once in a while a prim will decide to change its size so very small that you cant notice it, or move slightly, for various reasons... maybe thats what happened... also, I'd recomend checking it at every light type.. for the non Windlight try all of the daytime settings you can, for the Windlight, keep focused on the gap and scroll through all day times. Lighting can make a difference in problems like this, as if they aren't full bright they will be different shades based on the light. This has caused problems for me personally before, I always fixed by darkening the offending faces.

I did reenter all the prim sizes and coordinates on the off chance the parameters maybe out to a dp not displayed in the UI, but still no luck. I also tried changing the sun position in both viewers, but the gap still remained! I can only assume I had a buggy prim, as once I created a new one with equivalent parameters, the gap vanished!

Thanks for your replies Okiphia.

My pleasure, glad to know its fixed and working right now ^^

SL can be evil =P

I've dealt with this kind of thing many times. The problem is usually that the position may look perfect looking at the edit window numbers (to 3 decimal places), but if you get the position by script, it may be out. The position a script returns is to 5 decimal places.

I have scripts that I use to snap the positions of objects to exactly what they should be, and to snap the rotations of objects to exactly what they should be. This almost always fixes the gap.

Moving or rotating prims can mess up the accuracy again, although I think if you link the objects immediately after getting the positions and rotations perfect, then rotating or moving the linkset as a whole should not introduce new gaps.

Oddly enough I have never had the scales of prims be off from what I type in.

also beware of small changes in size, position and rotation, as they may update in world but not always on the viewer (there are some threshold limits, as well as limits in how small a change can be)...

I've also noticed a weirdness when aligning textures, that joined prims with aligned textures will show a line after editing them into place (or sometimes different lighting), but it I leave and come back they are seamless

sometimes when this happens and all numbers are correct, no minute accidental rotation, etc, i'll re-login. if that doesnt work then ill just re-create. its a last resort but often works. often theres some server/client hiccups that cause this and stay stuck in the objects.

Say Seifert, could you point me to those scripts you mentioned?

This script will snap your rotations to right angles relative to the world axes. What you want from a script that snaps to positions depends on what it is you're doing. Sometimes you want to snap to meter scale, sometimes to 0.25, or to 0.1 etc. This script doesn't do position snapping, you kindof need a different one for each project.

//Round rotations to line up with axes
//by Seifert Surface
float d = 0.1;
float round_quat(float x)
{
if(llFabs(x) < d)
return 0.0;
else if(llFabs(x - 1.0) < d)
return 1.0;
else if(llFabs(x +1.0) < d)
return -1.0;
else if(llFabs(x - 0.5) < d)
return 0.5;
else if(llFabs(x + 0.5) < d)
return -0.5;
else if(llFabs(x - 0.7071067 < d)
return 0.70710678;
else if(llFabs(x + 0.7071067 < d)
return -0.70710678;
else
return x;
}
round_rot()
{
rotation rot_new = llGetRot();
rot_new.x = round_quat(rot_new.x);
rot_new.y = round_quat(rot_new.y);
rot_new.z = round_quat(rot_new.z);
rot_new.s = round_quat(rot_new.s);
llSetRot(rot_new);
}
default
{
state_entry()
{
round_rot();
llRemoveInventory(llGetScriptName());
}
}

Dang nab it! Now I have to go help noobs get the boxes off their heads to get my brownie points for today!

Heh, glad you got it worked out in the end though.

Happy building,
~Maddy

Repositioning is what I'm really interested in, but I think I got the general idea from your script, at least on how to find/set the positions to eight decimal places. SL's got some pretty funky rounding practices it seems...

Thanks a bunch!

It only actually does it to 5 decimal places, but what the hell...

This is the function I would use to round a float x to a half meter, may well help:

float round2(float x)
{
return 0.5 * llRound(2.0 * x);
}