topic Re: MASS{2} edges participate in line elimination? in Libraries & objects

MASS{2} edges participate in line elimination?

Pertti Paasky — Sun, 14 Sep 2014 09:52:03 GMT

Hello Graphisoft
Can You please explain what this j9 means?
Thank You.

GDL manual page 102:
MASS{2} top_material, bottom_material, side_material,
n, m, mask, h,
x1, y1, z1, s1,
...
xn, yn, zn, sn,
xn+1, yn+1, zn+1, sn+1,
...
xn+m, yn+m, zn+m, sn+m
Extension of the MASS command with an additional mask bit and the possibility of hiding all top edges of the mass.
mask:
mask = j1 + 4*j3 + 16*j5 + 32*j6 + 64*j7 + 128*j8 + 256*j9 + 512*j10, where each j can be 0 or 1.
j1: base surface is present,
j3: side surfaces are present,
j5: base and side edges are visible,
j6: top edges are visible,
j7: top edges are visible, top surface is not smooth,
j8: all ridges will be sharp, but the surface is smooth.
j9: edges participate in line elimination.
j10: all top edges will be hidden.

Re: MASS{2} edges participate in line elimination?

Laszlo Nagy — Tue, 16 Sep 2014 22:16:45 GMT

As you know in 3D when there are two adjoining elements some face of which are co-planar then the line at their join will be removed. So for example two Walls, their outer face is in the same plane, one is 1 meter high, the other is 3 meters high: that 1 meter high common edge line will be eliminated in 3D from their face if they have the same surface material.
I suppose this option is used for the same purpose: to allow lines of GDL objects to be eliminated or to forbid line elimination for them.
Check page 57 in the GDL Reference Guide, there is an example for the CROOF_{3} command. It shows how certain lines of adjoining prisms having the same surface are eliminated based on such status codes.

Re: MASS{2} edges participate in line elimination?

Anonymous — Wed, 17 Sep 2014 06:15:42 GMT

Thanks Laszlo,
i was searching in the guide and now i know where to search.

Re: MASS{2} edges participate in line elimination?

Pertti Paasky — Thu, 18 Sep 2014 07:06:09 GMT

Ok, thanks. I suppose it is a useful option. Also "all top edges will be hidden" is intresting. In sections it shows only the cut section but not the background lines of the mass.

However it would be nice to show the edges of a curved surface (like in EDGE command status bit 2 page 133in the manual). If I draw contour lines in my mass-object I do not want to show them in the facades and sections. Only outlines and hidden lines are desired.

Re: MASS{2} edges participate in line elimination?

Laszlo Nagy — Thu, 18 Sep 2014 16:33:37 GMT

You can always make a wish if you would like to see a feature in a future version of the program.