implement coarsen and JacobiDet functions

HoBeZwe · Jun 18, 2024 · d279136 · d279136
1 parent 75d2315
commit d279136
Show file tree

Hide file tree

Showing 6 changed files with 47 additions and 3 deletions.
diff --git a/ext/plotting.jl b/ext/plotting.jl
@@ -174,7 +174,7 @@ function NURBS.plotPatches(Patches; plotControlPoints=true, enforceRatio=true, r
  traces = PlotlyJS.GenericTrace[]
  maxvec = Float64[]
 
- col = 1:size(Patches, 1)
+ col = 1 .+ rand(length(Patches))#1:size(Patches, 1)
 
  for (ind, patch) in enumerate(Patches)
 

diff --git a/src/NURBS.jl b/src/NURBS.jl
@@ -19,7 +19,7 @@ export evalNaive, evalNaiveDerivative
 export Jacobian, JacobiDet
 
 export insertKnot!, insertKnot
-export refine # NOTE: split is an extension of Base.split, i.e., it is publicly available without export
+export coarsen, refine # NOTE: split is an extension of Base.split, i.e., it is publicly available without export
 export removeKnot!, removeKnot, removeKnotU, removeKnotV
 
 export readMultipatch, readStep

diff --git a/src/fundamentalOperations/knotRemoval.jl b/src/fundamentalOperations/knotRemoval.jl
@@ -110,6 +110,30 @@ function removeKnotV(S::Surface, pointToRemove::Real, multiplicity::Int)
 end
 
 
+"""
+ coarsen(knotVec, controlPoints, degree::Int, pointsToRemove::Vector, weights=[])
+
+Coarsen a curve by removing parametric points from a curve's knot vector.
+
+NOTE: There are more efficient ways to do this.
+"""
+function coarsen(knotVec, controlPoints, degree::Int, pointsToRemove::Vector, weights=[])
+
+ # --- make copies
+ knotVecMod = deepcopy(knotVec)
+ controlPointsMod = deepcopy(controlPoints)
+ weightsMod = deepcopy(weights)
+
+ # --- modify copies
+ for (i, remPoint) in enumerate(pointsToRemove)
+ checkRange(remPoint)
+ removeKnot!(knotVecMod, controlPointsMod, degree, remPoint, 1, weightsMod)
+ end
+
+ return knotVecMod, controlPointsMod, weightsMod
+end
+
+
 """
  removeKnot(knotVec, controlPoints, degree::Int, pointToRemove::Real, multiplicity::Int, weights)
 
@@ -249,7 +273,6 @@ function trimControlPoints!(cPts, kVecOri, degree::Int, pos::Int, pointToRemove:
 
  # --- can knot be removed? Two different cases to be covered
  if j - i < t
-
  temp[ii] ≈ temp[jj + 2] && (removable = true)
  wemp[ii] ≈ wemp[jj + 2] && (removableW = true)
  else

diff --git a/src/utils.jl b/src/utils.jl
@@ -168,6 +168,19 @@ function JacobiDet(Ju, Jv)
  return dJ
 end
 
+function JacobiDet(Ju::SVector{3,T}, Jv::SVector{3,T}) where {T}
+
+ xu = Ju[1]
+ yu = Ju[2]
+ zu = Ju[3]
+
+ xv = Jv[1]
+ yv = Jv[2]
+ zv = Jv[3]
+
+ return sqrt((yu * zv - zu * yv)^2 + (zu * xv - xu * zv)^2 + (xu * yv - yu * xv)^2)
+end
+
 
 """
  spanRanges(Bspl::Bspline, points)

diff --git a/test/fundamentalOperations/knotRemoval.jl b/test/fundamentalOperations/knotRemoval.jl
@@ -26,6 +26,10 @@
  BC = BsplineCurve(Bspline(p, kVec), cP)
 
  RC = removeKnot(BC, 0.5, 3)
+ kVecMod, cPmod, wMod = coarsen(kVec, cP, p, [0.5, 0.5, 0.5])
+
+ @test RC.basis.knotVec == kVecMod
+ @test RC.controlPoints == cPmod
 
  cPR = RC.controlPoints
 

diff --git a/test/surfaces_nurbs.jl b/test/surfaces_nurbs.jl
@@ -116,6 +116,10 @@
  @test S[2, 1][1, 1] ≈ SVector(4.4444444444, 0.0, 0.0)
  @test S[2, 2][1, 1] ≈ SVector(-3.950617283, 0.0, 0.0)
 
+ a = SVector(2.1, 0.0, 1.0)
+ b = SVector(0.0, 0.0, 3.4)
+ @test JacobiDet(a, b) == norm(a × b) # area of parallelogram spanned by a and b
+
  @test_nowarn Jacobian(Patch, uEvalpoints, vEvalpoints)