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wip try rfunctions with dual contours #43

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wip try rfunctions with dual contours #43

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3 changes: 2 additions & 1 deletion examples/fea.jl
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
using Descartes
using Meshing

# params
beam_size = [50,10,10]
Expand All @@ -17,4 +18,4 @@ for i = 1:hole_ct
global c = diff(c, h)
end

save("fea.ply",HomogenousMesh(c))
save("fea.ply",HomogenousMesh(c, samples=(50,50,50), algorithm=DualContours()))
22 changes: 14 additions & 8 deletions src/frep.jl
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Original file line number Diff line number Diff line change
@@ -1,8 +1,14 @@
# http://en.wikipedia.org/wiki/Function_representation

# rvechev functions for smooth max and min
rmax(x,y) = (x+y+sqrt((x-y)^2))/2
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should be x+y under sqrt. also not sure about the division by 2

rmax(x, y, z...) = rmax(x, rmax(y,z...))
rmin(x,y) = (x+y-sqrt((x-y)^2))/2
rmin(x, y, z...) = rmin(x, rmin(y,z...))

function _radius(a,b,r)
if abs(a-b) >= r
return min(a,b)
return rmin(a,b)
else
return b+r*sin(pi/4+asin((a-b)/(r*sqrt(2))))-r
end
Expand All @@ -21,7 +27,7 @@ function FRep(p::Cylinder, v)
x = v[1]*it[1,1]+v[2]*it[1,2]+v[3]*it[1,3]+it[1,4]
y = v[1]*it[2,1]+v[2]*it[2,2]+v[3]*it[2,3]+it[2,4]
z = v[1]*it[3,1]+v[2]*it[3,2]+v[3]*it[3,3]+it[3,4]
max(-z+p.bottom, z-p.height-p.bottom, sqrt(x*x + y*y) - p.radius)
rmax(-z+p.bottom, z-p.height-p.bottom, sqrt(x*x + y*y) - p.radius)
end

function FRep(p::Cuboid, v)
Expand All @@ -31,26 +37,26 @@ function FRep(p::Cuboid, v)
z = v[1]*it[3,1]+v[2]*it[3,2]+v[3]*it[3,3]+it[3,4]
dx, dy, dz = p.dimensions
lbx, lby,lbz = p.lowercorner
max(-x+lbx, x-dx-lbx,
rmax(-x+lbx, x-dx-lbx,
-y+lby, y-dy-lby,
-z+lbz, z-dz-lbz)
end

function FRep(u::CSGUnion, v)
min(FRep(u.left, v),FRep(u.right, v))
rmin(FRep(u.left, v),FRep(u.right, v))
end

function FRep(u::CSGDiff, v)
max(FRep(u.left, v), -FRep(u.right, v))
rmax(FRep(u.left, v), -FRep(u.right, v))
end

function FRep(u::CSGIntersect, v)
max(FRep(u.left, v), FRep(u.right, v))
rmax(FRep(u.left, v), FRep(u.right, v))
end

function FRep(s::Shell, v)
r = FRep(s.primitive, v)
max(r, -r-s.distance)
rmax(r, -r-s.distance)
end

function FRep(u::RadiusedCSGUnion, v)
Expand Down Expand Up @@ -85,5 +91,5 @@ end

function FRep(p::LinearExtrude, v)
r = FRep(s.primitive, v)
max(max(-z,z-p.height), r)
rmax(rmax(-z,z-p.height), r)
end