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<p>Dear gmsh-users,</p>
<p><br>
</p>
<p>I ran into a problem with second order meshing of a Ruled Surface. If this surface is oriented along the x axis, I get a bad distortion. If I orient the same surface along the y axis, this problem does not occure. First order meshing work fine in both cases.<br>
</p>
<p>Is there a difference in the meshing algorithm for both axes?</p>
<p><br>
</p>
<p>An example with the two surfaces oriented along both axis is attached below.</p>
<p><br>
</p>
<p>I would<span> appreciate some hints to get a nice meshing in both directions.</span><br>
</p>
<p><span>Thanks!</span></p>
<p><br>
</p>
<p><span>Best regards,</span></p>
<p><span>Andreas Düdder</span></p>
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</p>
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<p><br>
</p>
<p>d = 0.025; <br>
lc = 0.0007; <br>
r = 0.001; <br>
l = d/2; <br>
<br>
<br>
<br>
//surface parallel to x<br>
c1center = newp; Point(c1center) = {0, 0, 0, lc};<br>
c1_2 = newp; Point(c1_2) = {0, 0,r, lc};<br>
c1_3 = newp; Point(c1_3) = {0, r,0, lc};<br>
circle1_2 = newl; Circle(circle1_2) = {c1_2,c1center,c1_3};<br>
<br>
point_s_2 = newp; Point(point_s_2) = {l, 0, 3*r+0.0004, lc};<br>
point_s_3 = newp; Point(point_s_3) = {l, r, 2*r+0.0004, lc};<br>
<br>
c2center = newp; Point(c2center) = {d, 0, 0, lc};<br>
c2_2 = newp; Point(c2_2) = {d, 0, r, lc};<br>
c2_3 = newp; Point(c2_3) = {d, r, 0, lc};<br>
circle2_2 = newl; Circle(circle2_2) = {c2_2,c2center,c2_3};<br>
<br>
spline_2 = newl; Spline(spline_2) = {c1_2,point_s_2,c2_2};<br>
spline_3 = newl; Spline(spline_3) = {c1_3,point_s_3,c2_3};<br>
<br>
axial_surface_2_loop = newll; Line Loop(axial_surface_2_loop) = {spline_2,circle2_2,-spline_3,-circle1_2};<br>
axial_surface_2 = news; Ruled Surface(axial_surface_2) = {axial_surface_2_loop};<br>
<br>
<br>
//surface parallel to y;<br>
c1center = newp; Point(c1center) = {0, 0, 2*r, lc};<br>
c1_2 = newp; Point(c1_2) = {0, 0, 3*r, lc};<br>
c1_3 = newp; Point(c1_3) = {r, 0, 2*r, lc};<br>
circle1_2 = newl; Circle(circle1_2) = {c1_2,c1center,c1_3};<br>
<br>
point_s_2 = newp; Point(point_s_2) = {0, l, 5*r+0.0004, lc};<br>
point_s_3 = newp; Point(point_s_3) = {r, l, 4*r+0.0004, lc};<br>
<br>
c2center = newp; Point(c2center) = {0, d, 2*r, lc};<br>
c2_2 = newp; Point(c2_2) = {0, d, 3*r, lc};<br>
c2_3 = newp; Point(c2_3) = {r, d, 2*r, lc}; <br>
circle2_2 = newl; Circle(circle2_2) = {c2_2,c2center,c2_3};<br>
<br>
<br>
spline_2 = newl; Spline(spline_2) = {c1_2,point_s_2,c2_2};<br>
spline_3 = newl; Spline(spline_3) = {c1_3,point_s_3,c2_3};<br>
<br>
axial_surface_2_loop = newll; Line Loop(axial_surface_2_loop) = {spline_2,circle2_2,-spline_3,-circle1_2}; <br>
axial_surface_2 = news; Ruled Surface(axial_surface_2) = {axial_surface_2_loop};<br>
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