Gap and primitive.

[Bertrand Lequy]

Hi,


I'm using the 3-16ndis.dat primitive in the part I'm working on (35103).


In fact I had to slice a 2-4ndis, so I replaced it by two 3-16ndis and the two quads I get using SlicerPro.


The matter is that, there's a realy small gap between the 3-16ndis primitive and each quad. But this gap disappears when I inline the primitive with LDDP, so I deduced it's a matter of precision using SlicerPro. The problem is that even with a better precision the gap is still here.
I've the same problem with 3-8cyli.dat for the vertical part.


So my question is : should I keep the primitive and the gap, or should I inline the primitive to close the gap ?


Or maybe there's  a third way I didn't thought about...

[Philippe Hurbain]

It's difficult to give good advice without seeing the data - can you share the file - or better another simplified one showing the problem?

[Bertrand Lequy]

It's difficult to give good advice without seeing the data - can you share the file - or better another simplified one showing the problem?

thank you for your answer, here it is : (I colored the primitives in green and the problematic quads in red, the vertical ones are realy thin)

Code:

0 // 140-144
1 16 2.5 144 5.25 2 0 0 0 -1 0 0 0 -2 2-4ndis.dat
1 16 2.5 144 5.25 2 0 0 0 1 0 0 0 -2 2-4edge.dat
0 BFC INVERTNEXT
1 16 2.5 144 5.25 2 0 0 0 -4 0 0 0 2 4-4cyli.dat

0 // 144
3 16 0.5 144 5.25 0.649 144 6 0.5 144 6
3 16 4.351 144 6 4.5 144 5.25 4.5 144 6
2 24 0.649 144 6 0.5 144 6
2 24 0.5 144 5.25  0.649 144 6
0 // 144-148
1 2 2.5 148 5.25 1.848 0 -0.765 0 -4 0 0.765 0 1.848 3-8cyli.dat
4 4 0.649 148 6 0.6522 148 6.0154 0.6522 144 6.0154 0.649 144 6
4 16 0.649 148 6 0.5 148 6 0.5 144 6 0.649 144 6
4 4 4.351 148 6 4.3478 148 6.0154 4.348 144 6.015 4.351 144 6
4 16 4.351 148 6 4.5 148 6 4.5 144 6 4.351 144 6
2 24 0.649 148 6 0.649 144 6
2 24 4.351 148 6 4.351 144 6

0 // 148
0 BFC INVERTNEXT
1 2 2.5 148 5.25 0 0 -2 0 1 0 2 0 0 3-16ndis.dat

0 0.6522 148 6.0154 <----------------------------first problematic vertex

0 BFC INVERTNEXT
1 2 2.5 148 5.25 0 0 2 0 1 0 2 0 0 3-16ndis.dat

0 4.3478 148 6.0154 <----------------------------second problematic vertex

0 BFC INVERTNEXT
1 16 2.5 148 5.25 1.848 0 -0.765 0 1 0 0.765 0 1.848 3-8edge.dat
4 4 0.5 148 6 0.5 148 7.25 0.6522 148 6.0154 0.649 148 6
4 4 4.351 148 6 4.3478 148 6.0154 4.5 148 7.25 4.5 148 6
2 24 0.6490196 148 6 0.6522 148 6.0154
2 24 0.6490196 148 6 0.5 148 6
2 24 4.351 148 6 4.3478 148 6.0154
2 24 4.351 148 6 4.5 148 6
2 24 4.351 144 6 4.5 144 6
2 24 4.351 144 6 4.5 144 5.25

[Gerald Lasser]

Hi

I would replace the

1 2 2.5 148 5.25 1.848 0 -0.765 0 -4 0 0.765 0 1.848 3-8cyli.dat

with

1 2 2.5 148 5.25 0 0 -2 0 -4 0 2 0 0 3-16cyli.dat
1 2 2.5 148 5.25 0 0 2 0 -4 0 2 0 0 3-16cyli.dat

so you avoid a 67.5 deg rotated part (3-8clyi) touching a non-rotated one (ndis)

I cannot see the issue with the inlining, I am using LDPE, though.

I would then move the two quads
4 16 0.649 148 6 0.5 148 6 0.5 144 6 0.649 144 6
4 16 4.351 148 6 4.5 148 6 4.5 144 6 4.351 144 6


to touch the 3-16 ndis
4 16 .6523477 148 6.0157893 .5 148 6.0154 .5 144 6.0154 .6522 144 6.0154
4 16 4.348 148 6.015 4.5 148 6.0154 4.5 144 6.0154 4.348 144 6.015

I  do not know where in the part (WHAT a part...) this sits, but the 0.0154 LDU should be possile to accommodate without any visual imparment, if you need them to be at Z=6 then I would even consider the quads like this

4 16 .6523477 148 6.0157893 .5 148 6 .5 144 6 .6522 144 6.0154
4 16 4.348 148 6.015 4.5 148 6 4.5 144 6 4.348 144 6.015

Touching the 3-8ndis at 6.0154 and the other side at 6

Gerald

[Bertrand Lequy]

Hi

I would replace the

1 2 2.5 148 5.25 1.848 0 -0.765 0 -4 0 0.765 0 1.848 3-8cyli.dat

with

1 2 2.5 148 5.25 0 0 -2 0 -4 0 2 0 0 3-16cyli.dat
1 2 2.5 148 5.25 0 0 2 0 -4 0 2 0 0 3-16cyli.dat

so you avoid a 67.5 deg rotated part (3-8clyi) touching a non-rotated one (ndis)

I cannot see the issue with the inlining, I am using LDPE, though.

I would then move the two quads
4 16 0.649 148 6 0.5 148 6 0.5 144 6 0.649 144 6
4 16 4.351 148 6 4.5 148 6 4.5 144 6 4.351 144 6


to touch the 3-16 ndis
4 16 .6523477 148 6.0157893 .5 148 6.0154 .5 144 6.0154 .6522 144 6.0154
4 16 4.348 148 6.015 4.5 148 6.0154 4.5 144 6.0154 4.348 144 6.015

I  do not know where in the part (WHAT a part...) this sits, but the 0.0154 LDU should be possile to accommodate without any visual imparment, if you need them to be at Z=6 then I would even consider the quads like this

4 16 .6523477 148 6.0157893 .5 148 6 .5 144 6 .6522 144 6.0154
4 16 4.348 148 6.015 4.5 148 6 4.5 144 6 4.348 144 6.015

Touching the 3-8ndis at 6.0154 and the other side at 6

Gerald

Thank you for your help, replacing the 3-8cyli by 2 3-16cyli helped  a lot. I check all the coordinates (some fourth decimal were incorect) and it seems to be ok for now.

[Bertrand Lequy]

I finally finished this one. Thank you again.
https://www.ldraw.org/cgi-bin/ptdetail.c.../35103.dat