COMSOL Multiphysics™

geomcsg
TABLE 1-57: GEOMETRY MODEL OR DRAW STRUCTURE
FIELD 1D 2D 3D DESCRIPTION
f.name ♦ Cell array of names (ignored by
geomcsg)
c.objs ♦ ♦ Cell array of curve objects.
c.name ♦ ♦ Cell array of names (ignored by
geomcsg)
p.objs ♦ ♦ ♦ Cell array of point objects.
p.name ♦ ♦ ♦ Cell array of names (ignored by
geomcsg)
Examples
3D Geometries
Perform a solid operation on two intersecting cylinders:
s1=cylinder3(2,2,[0.5 0.5 -1],[0 0 1]);
s2=cylinder3(1,1,[0.5 0.5 -0.5],[0 0 1]);
[g,st,stx]=geomcsg({s1,s2},'out',{'g','st','stx'},...
'ns',{'Cyl1','Cyl2'},'sf','Cyl1-Cyl2');
To easily create solid objects, use the overloaded operators +, *, and -, instead of
calling geomcsg:
s=s1-s2;
geomplot(s,'facemode','off')
s and g are equivalent, except that g is a geom3 object while s is a solid3 object.
2D Geometries
Create a unit circle solid object and a unit square solid object:
c1 = circ2;
sq1 = square2;
g = geomcsg({c1 sq1},{},'ns',{'a' 'b'},'sf','a-b');
Using object arithmetic for solid objects, the same result can be obtained by typing.
g = c1-sq1;
You can plot the geometry object by
geomplot(g,'sublabel','on','edgelabel','on')
or just
geomplot(g)
You can obtain the number of subdomains and edge segment by just typing g or by
explicitly getting the object properties.
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