Skip to content
Snippets Groups Projects
topologyOptimization.jl 106 KiB
Newer Older
# Amira Abdel-Rahman
# (c) Massachusetts Institute of Technology 2020

# Topology Optimization Implementation in Julia from various sources
# based on https://paulino.ce.gatech.edu/conferences/papers/11pereira_anefficientandcompact.pdf and http://www.topopt.mek.dtu.dk/apps-and-software and https://github.com/blademwang11/Topopt/blob/master/top.jl

#######################################2d##################################################################
function topologyOptimization(nelx,nely,volfrac,rmin,penal)
    anim=Animation()
    
    display("Minimum compliance problem with OC")
    display("ndes: $nelx x $nely")
    display("volfrac: $volfrac rmin: $rmin penal: $penal")
    # Max and min stiffness
    Emin=1e-9
    Emax=1.0
    # dofs:
    ndof = 2*(nelx+1)*(nely+1)
    # Allocate design variables (as array), initialize and allocate sens.
    x=volfrac * ones(Float64,nely,nelx)
    xold=copy(x)
    xPhys=copy(x)
    g=0 # must be initialized to use the NGuyen/Paulino OC approach
    dc=zeros(Float64,(nely,nelx))
    
    # FE: Build the index vectors for the for coo matrix format.
    KE=lk()
    nodenrs = reshape(1:(1+nelx)*(1+nely),1+nely,1+nelx)
    edofVec = reshape(2*nodenrs[1:end-1,1:end-1].+1,nelx*nely,1)
    edofMat = repeat(edofVec,1,8).+repeat([0 1 2*nely.+[2 3 0 1] -2 -1],nelx*nely,1)
    iK = convert(Array{Int},reshape(kron(edofMat,ones(8,1))',64*nelx*nely,1))
    jK = convert(Array{Int},reshape(kron(edofMat,ones(1,8))',64*nelx*nely,1))
    # DEFINE LOADS AND SUPPORTS (HALF MBB-BEAM)
    F = sparse([2],[1],[-1.0],2*(nely+1)*(nelx+1),1)
    U = zeros(2*(nely+1)*(nelx+1),1)
    fixeddofs = union(1:2:2*(nely+1),2*(nelx+1)*(nely+1))
    alldofs = 1:(2*(nely+1)*(nelx+1))
    freedofs = setdiff(alldofs,fixeddofs)
    # Prepare filter
    iH = ones(convert(Int,nelx*nely*(2*(ceil(rmin)-1)+1)^2),1)
    jH = ones(Int,size(iH))
    sH = zeros(size(iH))
    k = 0;
    for i1 = 1:nelx
        for j1 = 1:nely
            e1 = (i1-1)*nely+j1
            for i2 = max(i1-(ceil(rmin)-1),1):min(i1+(ceil(rmin)-1),nelx)
                for j2 = max(j1-(ceil(rmin)-1),1):min(j1+(ceil(rmin)-1),nely)
                    e2 = (i2-1)*nely+j2
                    k = k+1
                    iH[k] = e1
                    jH[k] = e2
                    sH[k] = max(0,rmin-sqrt((i1-i2)^2+(j1-j2)^2))
                end
            end
        end
    end
    H = sparse(vec(iH),vec(jH),vec(sH))
    Hs = sum(H,dims=2)
    ###################################################
    loop = 0
    change = 1
    maxIter=1000
    # Start iteration
    for i =1:maxIter
        if (change > 0.01)
            # Start iteration
            loop += 1
            # FE-ANALYSIS
            sK = reshape(KE[:]*(Emin.+xPhys[:]'.^penal*(Emax-Emin)),64*nelx*nely,1)
            K = sparse(vec(iK),vec(jK),vec(sK)); K = (K+K')/2
            @timed U[freedofs] = K[freedofs,freedofs] \ Array(F[freedofs])
            # Objective function and sensitivity analysis
            ce = reshape(sum((U[edofMat]*KE).*U[edofMat],dims=2),nely,nelx)
            c = sum(sum((Emin.+xPhys.^penal*(Emax-Emin)).*ce))
            
            dc = -penal*(Emax-Emin)*xPhys.^(penal-1).*ce
            dv = ones(nely,nelx)
            dc[:] = H*(dc[:]./Hs)
            dv[:] = H*(dv[:]./Hs)
            # OPTIMALITY CRITERIA UPDATE OF DESIGN VARIABLES AND PHYSICAL DENSITIES
            l1 = 0; l2 = 1e9; move = 0.2; xnew = 0
            while (l2-l1)/(l1+l2) > 1e-3
                lmid = 0.5*(l2+l1)
                xnew = max.(0,max.(x.-move,min.(1,min.(x.+move,x.*sqrt.((0.0.-dc)./dv./lmid)))))
                xPhys[:] = (H*xnew[:])./Hs
                if sum(xPhys[:]) > volfrac*nelx*nely
                    l1 = lmid
                else
                    l2 = lmid
                end
            end
            change = maximum(abs.(xnew[:].-x[:]))
            x = xnew
            m=mean(xPhys[:])
            display(" It:$loop Obj:$c Vol:$m ch:$change ")
            if loop<20||mod(loop,10)==0
                xxx=1 .- clamp.(xPhys,0,1)
                display(heatmap(xxx,xaxis=nothing,yaxis=nothing,legend=nothing,fc=:grays,clims=(0.0, 1.0),aspect_ratio=:equal))
                heatmap(xxx,xaxis=nothing,yaxis=nothing,legend=nothing,fc=:grays,clims=(0.0, 1.0),aspect_ratio=:equal)
                frame(anim)
            end

            xPhys = copy(x)
        end
    end
    return xPhys,anim
end

#########################################################################################################

function CompliantTopologyOptimization(nelx,nely,volfrac,rmin,penal,maxIter,Load,Support,Spring,DOut)
    anim=Animation()
    display("Minimum compliance problem with OC")
    display("ndes: $nelx x $nely")
    display("volfrac: $volfrac rmin: $rmin penal: $penal")
    # Max and min stiffness
    Emin=1e-9
    Emax=1.0
    change = 1
    # dofs:
    ndof = 2*(nelx+1)*(nely+1)
    # Allocate design variables (as array), initialize and allocate sens.
    x=volfrac * ones(Float64,nely,nelx)
    xold=copy(x)
    xPhys=copy(x)
    g=0 # must be initialized to use the NGuyen/Paulino OC approach
    dc=zeros(Float64,(nely,nelx))
    
    # FE: Build the index vectors for the for coo matrix format.
    KE=lk()
    nodenrs = reshape(1:(1+nelx)*(1+nely),1+nely,1+nelx)
    edofVec = reshape(2*nodenrs[1:end-1,1:end-1].+1,nelx*nely,1)
    edofMat = repeat(edofVec,1,8).+repeat([0 1 2*nely.+[2 3 0 1] -2 -1],nelx*nely,1)
    iK = convert(Array{Int},reshape(kron(edofMat,ones(8,1))',64*nelx*nely,1))
    jK = convert(Array{Int},reshape(kron(edofMat,ones(1,8))',64*nelx*nely,1))
    
    
    # DEFINE LOADS AND SUPPORTS 
    F = sparse(2 .*Load[:,1] .-2 .+ Load[:,2],ones(size(Load,1)),Load[:,3],2*(nely+1)*(nelx+1),2)
    DofDOut = 2 * DOut[1] - 2 +DOut[2]; #only one
    F=Array(F)
    F[DofDOut,2]=-1
    fixeddofs = 2 .*Support[:,1] .-2 .+ Support[:,2]
    NSpring = size(Spring,1);
    s = sparse(2 .*Spring[:,1] .-2 .+ Spring[:,2],ones(size(Spring,1)),Spring[:,3],2*(nely+1)*(nelx+1),2)
    m=Array(s)[:,1]
    S= sparse(diagm(m))
    
    U = zeros(2*(nely+1)*(nelx+1),2)

    alldofs = 1:(2*(nely+1)*(nelx+1))
    freedofs = setdiff(alldofs,fixeddofs)
    
    # Prepare filter
    iH = ones(convert(Int,nelx*nely*(2*(ceil(rmin)-1)+1)^2),1)
    jH = ones(Int,size(iH))
    sH = zeros(size(iH))
    k = 0;
    for i1 = 1:nelx
        for j1 = 1:nely
            e1 = (i1-1)*nely+j1
            for i2 = max(i1-(ceil(rmin)-1),1):min(i1+(ceil(rmin)-1),nelx)
                for j2 = max(j1-(ceil(rmin)-1),1):min(j1+(ceil(rmin)-1),nely)
                    e2 = (i2-1)*nely+j2
                    k = k+1
                    iH[k] = e1
                    jH[k] = e2
                    sH[k] = max(0,rmin-sqrt((i1-i2)^2+(j1-j2)^2))
                end
            end
        end
    end
    H = sparse(vec(iH),vec(jH),vec(sH))
    Hs = sum(H,dims=2)
    
    change= 1
    loop = 0
    changeStable=0
    # Start iteration
    for penal in 1.0:0.5:4
        display(" Penalty: $penal")
        loop = 0
        for i =1:maxIter
            if (change < 0.01)
                changeStable+=1
                display(" Change Stable for $changeStable iterations")
            else
                changeStable=0
            end
            if (changeStable<10)
                # Start iteration
                loop += 1
                # FE-ANALYSIS
                sK = reshape(KE[:]*(Emin.+xPhys[:]'.^penal*(Emax-Emin)),64*nelx*nely,1)
                K = sparse(vec(iK),vec(jK),vec(sK))+S;K = (K+K')/2
                @timed U[freedofs,:] = K[freedofs,freedofs] \ Array(F[freedofs,:])
                U1=U[:,1]
                U2=U[:,2]
                # Objective function and sensitivity analysis
                #ce = reshape(sum((U1[edofMat]*KE).*U2[edofMat],dims=2),nely,nelx)

                ce=reshape(-sum((U1[edofMat]*KE).*U2[edofMat],dims=2),nely,nelx)

                #c = sum((Emin.+xPhys[:].^penal*(Emax-Emin)).*ce)

                c=U[DofDOut,1]

                dc = -penal.*(Emax-Emin).*xPhys.^(penal-1).*ce
                dv = ones(nely,nelx)
                dc[:] = H*(dc[:]./Hs)
                dv[:] = H*(dv[:]./Hs)

                # OPTIMALITY CRITERIA UPDATE OF DESIGN VARIABLES AND PHYSICAL DENSITIES
                l1 = 0; l2 = 1e9; move = 0.05; xnew = 0 #move=0.2
                while (l2-l1)/(l2+l1) > 1e-4 && l2>1e-40
                #while (l2-l1)/(l1+l2) > 1e-3
                    lmid = 0.5*(l2+l1)
                    xnew = max.(0,max.(x.-move,min.(1,min.(x.+move,x.*sqrt.(max.(1e-10,-dc./dv./lmid))))))
                    #xnew = max.(0,max.(x.-move,min.(1,min.(x.+move,x.*sqrt.(-dc./dv./lmid)))))
                    xPhys[:] = (H*xnew[:])./Hs
                    if sum(xPhys[:]) > volfrac*nelx*nely
                        l1 = lmid
                    else
                        l2 = lmid
                    end
                end
                change = maximum(abs.(xnew[:].-x[:]))
                x = xnew

                # print result
                m=mean(xPhys[:])
                display(" It:$loop Obj:$c Vol:$m ch:$change ")
                if loop<20||mod(loop,5)==0
                    xxx=vcat(xPhys[end:-1:1,:],xPhys)
                    xxx=1 .- xxx
                    display(heatmap(xxx,xaxis=nothing,yaxis=nothing,legend=nothing,fc=:grays,clims=(0.0, 1.0)))
                    heatmap(xxx,xaxis=nothing,yaxis=nothing,legend=nothing,fc=:grays,clims=(0.0, 1.0))
                    frame(anim)
                end

                xPhys = copy(x)
            end
        end
    end
    # heatmap(xPhys, legend=false, axis=nothing, foreground_color_subplot=colorant"white",fc=:grays,clims=(0.0, 1.0))
    # heatmap(xPhys, legend=false,fc=:grays,clims=(0.0, 1.0))
    return xPhys,anim
end


#########################################3d################################################################
function topologyOptimization3d(nelx,nely,nelz,volfrac,rmin,penal)
    anim=Animation()
    
    display("Minimum compliance problem with OC")
    display("ndes: $nelx x $nely")
    display("volfrac: $volfrac rmin: $rmin penal: $penal")
    # Max and min stiffness
    Emin=1e-9
    Emax=1.0
    nu=0.3
    # dofs:
    ndof = 3*(nelx+1)*(nely+1)*(nelz+1)
    # Allocate design variables (as array), initialize and allocate sens.
    x=volfrac * ones(Float64,nely,nelx,nelz)
    xold=copy(x)
    xPhys=copy(x)
    g=0 # must be initialized to use the NGuyen/Paulino OC approach
    dc=zeros(Float64,(nely,nelx,nelz))
    
    # FE: Build the index vectors for the for coo matrix format.
    KE=lk_H8(nu)
    nele = nelx*nely*nelz
    
    nodenrs = reshape(1:(1+nelx)*(1+nely)*(1+nelz),1+nely,1+nelx,1+nelz)
    edofVec = reshape(3*nodenrs[1:end-1,1:end-1,1:end-1].+1,nelx*nely*nelz,1)
    edofMat = repeat(edofVec,1,24).+repeat([0 1 2 3*nely.+[3 4 5 0 1 2] -3 -2 -1 3*(nely+1)*(nelx+1).+[0 1 2 3*nely.+[3 4 5 0 1 2] -3 -2 -1]],nelx*nely*nelz,1)
        
    iK = convert(Array{Int},reshape(kron(edofMat,ones(24,1))',24*24*nele,1))
    jK = convert(Array{Int},reshape(kron(edofMat,ones(1,24))',24*24*nele,1))
    
    
    
    
    # USER-DEFINED LOAD DOFs
    m= Matlab.meshgrid(nelx:nelx, 0:0, 0:nelz)
    il=m[1]
    jl=m[2]
    kl=m[3]
    loadnid = kl.*(nelx+1).*(nely+1).+il.*(nely+1).+(nely+1 .-jl)
    loaddof = 3 .*loadnid[:] .- 1; 
    # USER-DEFINED SUPPORT FIXED DOFs
    m= Matlab.meshgrid(0:0,0:nely,0:nelz)# Coordinates
    iif=m[1]
    jf=m[2]
    kf=m[3]
    fixednid = kf.*(nelx+1).*(nely+1) .+iif .*(nely .+1) .+(nely .+1 .-jf) # Node IDs
    fixeddof = [3 .*fixednid[:]; 3 .*fixednid[:].-1; 3 .*fixednid[:].-2] # DOFs
    
    
    # DEFINE LOADS AND SUPPORTS (HALF MBB-BEAM)
    F= sparse(loaddof,fill(1,length(loaddof)),fill(-1,length(loaddof)),ndof,1);
    U = zeros(ndof,1)
    alldofs = 1:ndof
    freedofs = setdiff(1:ndof,fixeddof)
    
    
    
    # Prepare filter
    #iH = ones(convert(Int,nele*(2*(ceil(rmin)-1)+1)^2),1)
    #jH = ones(Int,size(iH))
    #sH = zeros(size(iH))
    iH=[]
    jH=[]
    sH=[]
    k = 0

    for k1 = 1:nelz
        for i1 = 1:nelx
            for j1 = 1:nely
                e1 = (k1-1)*nelx*nely + (i1-1)*nely+j1
                for k2 = max(k1-(ceil(rmin)-1),1):min(k1+(ceil(rmin)-1),nelz)
                    for i2 = max(i1-(ceil(rmin)-1),1):min(i1+(ceil(rmin)-1),nelx)
                        for j2 = max(j1-(ceil(rmin)-1),1):min(j1+(ceil(rmin)-1),nely)
                            e2 = (k2-1)*nelx*nely + (i2-1)*nely+j2;
                            k = k+1;
                            append!(iH, e1  )
                            append!(jH, e2  )
                            append!(sH, max(0.0,rmin-sqrt((i1-i2)^2+(j1-j2)^2+(k1-k2)^2) ))
                            
                        end
                    end
                end
            end
        end
    end
    iH=reshape(iH,length(iH),1)
    jH=reshape(jH,length(jH),1)
    sH=reshape(convert(Array{Float64}, sH),length(sH),1)
    H = sparse(vec(iH),vec(jH),vec(sH))
    Hs = sum(H,dims=2)
    ###################################################
    loop = 0
    change = 1
    maxIter=1000
    # Start iteration
    for i =1:maxIter
        if (change > 0.01)
            # Start iteration
            loop += 1
            # FE-ANALYSIS
            sK = reshape(KE[:]*(Emin.+xPhys[:]'.^penal*(Emax-Emin)),24*24*nelx*nely*nelz,1)
            K = sparse(vec(iK),vec(jK),vec(sK)); K = (K+K')/2
            @timed U[freedofs] = K[freedofs,freedofs] \ Array(F[freedofs])
            # Objective function and sensitivity analysis
            ce = reshape(sum((U[edofMat]*KE).*U[edofMat],dims=2),nely,nelx,nelz)
            c = sum(sum(sum((Emin.+xPhys.^penal*(Emax-Emin)).*ce)))
            
            dc = -penal*(Emax-Emin)*xPhys.^(penal-1).*ce
            dv = ones(nely,nelx,nelz)
            dc[:] = H*(dc[:]./Hs)
            dv[:] = H*(dv[:]./Hs)
            # OPTIMALITY CRITERIA UPDATE OF DESIGN VARIABLES AND PHYSICAL DENSITIES
            l1 = 0; l2 = 1e9; move = 0.2; xnew = 0
            while (l2-l1)/(l1+l2) > 1e-3
                lmid = 0.5*(l2+l1)
                xnew = max.(0,max.(x.-move,min.(1,min.(x.+move,x.*sqrt.((0.0.-dc)./dv./lmid)))))
                xPhys[:] = (H*xnew[:])./Hs
                if sum(xPhys[:]) > volfrac*nelx*nely
                    l1 = lmid
                else
                    l2 = lmid
                end
            end
            change = maximum(abs.(xnew[:].-x[:]))
            x = xnew
            m=mean(xPhys[:])
            display(" It:$loop Obj:$c Vol:$m ch:$change ")
            if mod(loop,2)==0
                display(topplot3d(xPhys))
                topplot3d(xPhys)
                frame(anim)
            end

            xPhys = copy(x)
        end
    end
    return xPhys,anim
end

#########################################3d KE################################################################
function topologyOptimization3dKE(nelx,nely,nelz,volfrac,rmin,penal,CE)
    anim=Animation()
    
    display("Minimum compliance problem with OC")
    display("ndes: $nelx x $nely")
    display("volfrac: $volfrac rmin: $rmin penal: $penal")
    # Max and min stiffness
    Emin=1e-9
    Emax=1.0
    nu=0.3
    # dofs:
    ndof = 3*(nelx+1)*(nely+1)*(nelz+1)
    # Allocate design variables (as array), initialize and allocate sens.
    x=volfrac * ones(Float64,nely,nelx,nelz)
    xold=copy(x)
    xPhys=copy(x)
    g=0 # must be initialized to use the NGuyen/Paulino OC approach
    dc=zeros(Float64,(nely,nelx,nelz))
    
    # FE: Build the index vectors for the for coo matrix format.
    # KE=lk_H8(nu)

    KE = elementMatVec3D(0.5, 0.5, 0.5, CE);

    nele = nelx*nely*nelz
    
    nodenrs = reshape(1:(1+nelx)*(1+nely)*(1+nelz),1+nely,1+nelx,1+nelz)
    edofVec = reshape(3*nodenrs[1:end-1,1:end-1,1:end-1].+1,nelx*nely*nelz,1)
    edofMat = repeat(edofVec,1,24).+repeat([0 1 2 3*nely.+[3 4 5 0 1 2] -3 -2 -1 3*(nely+1)*(nelx+1).+[0 1 2 3*nely.+[3 4 5 0 1 2] -3 -2 -1]],nelx*nely*nelz,1)
        
    iK = convert(Array{Int},reshape(kron(edofMat,ones(24,1))',24*24*nele,1))
    jK = convert(Array{Int},reshape(kron(edofMat,ones(1,24))',24*24*nele,1))
    
    
    # USER-DEFINED LOAD DOFs
    m= Matlab.meshgrid(nelx:nelx, 0:0, 0:nelz)
    il=m[1]
    jl=m[2]
    kl=m[3]
    loadnid = kl.*(nelx+1).*(nely+1).+il.*(nely+1).+(nely+1 .-jl)
    loaddof = 3 .*loadnid[:] .- 1; 
    # USER-DEFINED SUPPORT FIXED DOFs
    m= Matlab.meshgrid(0:0,0:nely,0:nelz)# Coordinates
    iif=m[1]
    jf=m[2]
    kf=m[3]
    fixednid = kf.*(nelx+1).*(nely+1) .+iif .*(nely .+1) .+(nely .+1 .-jf) # Node IDs
    fixeddof = [3 .*fixednid[:]; 3 .*fixednid[:].-1; 3 .*fixednid[:].-2] # DOFs
    
    
    # DEFINE LOADS AND SUPPORTS (HALF MBB-BEAM)
    F= sparse(loaddof,fill(1,length(loaddof)),fill(-1,length(loaddof)),ndof,1);
    U = zeros(ndof,1)
    alldofs = 1:ndof
    freedofs = setdiff(1:ndof,fixeddof)
    
    
    
    # Prepare filter
    #iH = ones(convert(Int,nele*(2*(ceil(rmin)-1)+1)^2),1)
    #jH = ones(Int,size(iH))
    #sH = zeros(size(iH))
    iH=[]
    jH=[]
    sH=[]
    k = 0

    for k1 = 1:nelz
        for i1 = 1:nelx
            for j1 = 1:nely
                e1 = (k1-1)*nelx*nely + (i1-1)*nely+j1
                for k2 = max(k1-(ceil(rmin)-1),1):min(k1+(ceil(rmin)-1),nelz)
                    for i2 = max(i1-(ceil(rmin)-1),1):min(i1+(ceil(rmin)-1),nelx)
                        for j2 = max(j1-(ceil(rmin)-1),1):min(j1+(ceil(rmin)-1),nely)
                            e2 = (k2-1)*nelx*nely + (i2-1)*nely+j2;
                            k = k+1;
                            append!(iH, e1  )
                            append!(jH, e2  )
                            append!(sH, max(0.0,rmin-sqrt((i1-i2)^2+(j1-j2)^2+(k1-k2)^2) ))
                            
                        end
                    end
                end
            end
        end
    end
    iH=reshape(iH,length(iH),1)
    jH=reshape(jH,length(jH),1)
    sH=reshape(convert(Array{Float64}, sH),length(sH),1)
    H = sparse(vec(iH),vec(jH),vec(sH))
    Hs = sum(H,dims=2)
    ###################################################
    loop = 0
    change = 1
    maxIter=1000
    # Start iteration
    for i =1:maxIter
        if (change > 0.01)
            # Start iteration
            loop += 1
            # FE-ANALYSIS
            sK = reshape(KE[:]*(Emin.+xPhys[:]'.^penal*(Emax-Emin)),24*24*nelx*nely*nelz,1)
            K = sparse(vec(iK),vec(jK),vec(sK)); K = (K+K')/2
            @timed U[freedofs] = K[freedofs,freedofs] \ Array(F[freedofs])
            # Objective function and sensitivity analysis
            ce = reshape(sum((U[edofMat]*KE).*U[edofMat],dims=2),nely,nelx,nelz)
            c = sum(sum(sum((Emin.+xPhys.^penal*(Emax-Emin)).*ce)))
            
            dc = -penal*(Emax-Emin)*xPhys.^(penal-1).*ce
            dv = ones(nely,nelx,nelz)
            dc[:] = H*(dc[:]./Hs)
            dv[:] = H*(dv[:]./Hs)
            # OPTIMALITY CRITERIA UPDATE OF DESIGN VARIABLES AND PHYSICAL DENSITIES
            l1 = 0; l2 = 1e9; move = 0.2; xnew = 0
            while (l2-l1)/(l1+l2) > 1e-3
                lmid = 0.5*(l2+l1)
                xnew = max.(0,max.(x.-move,min.(1,min.(x.+move,x.*sqrt.((0.0.-dc)./dv./lmid)))))
                xPhys[:] = (H*xnew[:])./Hs
                if sum(xPhys[:]) > volfrac*nelx*nely
                    l1 = lmid
                else
                    l2 = lmid
                end
            end
            change = maximum(abs.(xnew[:].-x[:]))
            x = xnew
            m=mean(xPhys[:])
            display(" It:$loop Obj:$c Vol:$m ch:$change ")
            if mod(loop,5)==0
                display(topplot3d(xPhys))
                topplot3d(xPhys)
                frame(anim)
            end

            xPhys = copy(x)
        end
    end
    return xPhys,anim
end

#########################################################################################################

function compliantOptimization3d(nelx,nely,nelz,volfrac,rmin,penal,maxIter=500,getProblem=inverter)
    anim=Animation()

    display("Compliance sythesyz problem with OC")
    display("ndes: $nelx x $nely x $nelz")
    display("volfrac: $volfrac rmin: $rmin penal: $penal")
    # Max and min stiffness
    Emin=1e-9
    Emax=1.0
    nu=0.3
    # dofs:
    ndof = 3*(nelx+1)*(nely+1)*(nelz+1)
    # Allocate design variables (as array), initialize and allocate sens.
    x=volfrac * ones(Float64,nely,nelx,nelz)
    xold=copy(x)
    xPhys=copy(x)
    g=0 # must be initialized to use the NGuyen/Paulino OC approach
    dc=zeros(Float64,(nely,nelx,nelz))
    
    # FE: Build the index vectors for the for coo matrix format.
    KE=lk_H8(nu)
    nele = nelx*nely*nelz
    
    nodenrs = reshape(1:(1+nelx)*(1+nely)*(1+nelz),1+nely,1+nelx,1+nelz)
    edofVec = reshape(3*nodenrs[1:end-1,1:end-1,1:end-1].+1,nelx*nely*nelz,1)
    edofMat = repeat(edofVec,1,24).+repeat([0 1 2 3*nely.+[3 4 5 0 1 2] -3 -2 -1 3*(nely+1)*(nelx+1).+[0 1 2 3*nely.+[3 4 5 0 1 2] -3 -2 -1]],nelx*nely*nelz,1)
        
    iK = convert(Array{Int},reshape(kron(edofMat,ones(24,1))',24*24*nele,1))
    jK = convert(Array{Int},reshape(kron(edofMat,ones(1,24))',24*24*nele,1))
    
    
    
    
    # # USER-DEFINED LOAD DOFs
    # m= Matlab.meshgrid(nelx:nelx, 0:0, 0:nelz)
    # il=m[1]
    # jl=m[2]
    # kl=m[3]
    # loadnid = kl.*(nelx+1).*(nely+1).+il.*(nely+1).+(nely+1 .-jl)
    # loaddof = 3 .*loadnid[:] .- 1; 
    # # USER-DEFINED SUPPORT FIXED DOFs
    # m= Matlab.meshgrid(0:0,0:nely,0:nelz)# Coordinates
    # iif=m[1]
    # jf=m[2]
    # kf=m[3]
    # fixednid = kf.*(nelx+1).*(nely+1) .+iif .*(nely .+1) .+(nely .+1 .-jf) # Node IDs
    # fixeddof = [3 .*fixednid[:]; 3 .*fixednid[:].-1; 3 .*fixednid[:].-2] # DOFs
    
    
    # # DEFINE LOADS AND SUPPORTS (HALF MBB-BEAM)
    # F= sparse(loaddof,fill(1,length(loaddof)),fill(-1,length(loaddof)),ndof,1);
    # U = zeros(ndof,1)
    # alldofs = 1:ndof
    # freedofs = setdiff(1:ndof,fixeddof)
    # USER-DEFINED LOAD DOFs
    # il = [0 nelx]; jl = [nely nely]; kl = [0 0];
    # loadnid = kl .*(nelx+1) .*(nely+1) .+il .*(nely .+1) .+(nely+1 .-jl);
    # loaddof = 3 .*loadnid[:] .- 2;
    # din = loaddof[1]; dout = loaddof[2];
    # F = sparse(loaddof,[1;2],[1;-1],ndof,2);
    # # USER-DEFINED SUPPORT FIXED DOFs
    # # Top face
    # m = Matlab.meshgrid(0:nelx,0:nelz)
    # iif=m[1]
    # kf=m[2]
    # fixednid = kf .*(nelx+1) .*(nely+1) .+iif .*(nely+1) .+1;
    # fixeddof_t = 3 .*fixednid[:] .-1;
    # # Side face
    # m = Matlab.meshgrid(0:nelx,0:nely)
    # iif=m[1]
    # jf=m[2]
    # fixednid = iif .*(nely+1) .+(nely+1 .-jf);
    # fixeddof_s = 3*fixednid[:];
    # # Two pins
    # iif = [0;0]; jf = [0;1]; kf = [nelz;nelz];
    # fixednid = kf .*(nelx+1) .*(nely .+1) .+iif .*(nely .+1) .+(nely+1 .-jf)
    # fixeddof_p = [3 .*fixednid[:]; 3 .*fixednid[:].-1; 3 .*fixednid[:].-2] # DOFs
    # # Fixed DOFs
    # fixeddof = union(fixeddof_t,fixeddof_s);
    # fixeddof = union(fixeddof, fixeddof_p);
    # fixeddof = sort(fixeddof);
    
    # # Displacement vector
    # U = zeros(ndof,2);
    # freedofs = setdiff(1:ndof,fixeddof)

    U,F,freedofs,din,dout=getProblem(nelx,nely,nelz)

    
    
    # Prepare filter
    #iH = ones(convert(Int,nele*(2*(ceil(rmin)-1)+1)^2),1)
    #jH = ones(Int,size(iH))
    #sH = zeros(size(iH))
    iH=[]
    jH=[]
    sH=[]
    k = 0

    for k1 = 1:nelz
        for i1 = 1:nelx
            for j1 = 1:nely
                e1 = (k1-1)*nelx*nely + (i1-1)*nely+j1
                for k2 = max(k1-(ceil(rmin)-1),1):min(k1+(ceil(rmin)-1),nelz)
                    for i2 = max(i1-(ceil(rmin)-1),1):min(i1+(ceil(rmin)-1),nelx)
                        for j2 = max(j1-(ceil(rmin)-1),1):min(j1+(ceil(rmin)-1),nely)
                            e2 = (k2-1)*nelx*nely + (i2-1)*nely+j2;
                            k = k+1;
                            append!(iH, e1  )
                            append!(jH, e2  )
                            append!(sH, max(0.0,rmin-sqrt((i1-i2)^2+(j1-j2)^2+(k1-k2)^2) ))
                            
                        end
                    end
                end
            end
        end
    end

    iH=reshape(iH,length(iH),1)
    jH=reshape(jH,length(jH),1)
    sH=reshape(convert(Array{Float64}, sH),length(sH),1)
    H = sparse(vec(iH),vec(jH),vec(sH))
    Hs = sum(H,dims=2)
    ###################################################
    loop = 0
    change = 1
    # Start iteration
    for i =1:maxIter
        if (change > 0.01)
            # Start iteration
            loop += 1
            # FE-ANALYSIS
            sK = reshape(KE[:]*(Emin.+xPhys[:]'.^penal*(Emax-Emin)),24*24*nelx*nely*nelz,1)
            K = sparse(vec(iK),vec(jK),vec(sK)) 
            K[din,din] = K[din,din] + 0.1
            K[dout,dout] = K[dout,dout] + 0.1
            K = (K+K')/2
            
            
            # @timed U[freedofs] = K[freedofs,freedofs] \ Array(F[freedofs])
            @timed U[freedofs,:] = K[freedofs,freedofs] \ Array(F[freedofs,:])
            U1 = U[:,1]
            U2 = U[:,2]
            
            # Objective function and sensitivity analysis
            
            #ce = reshape(sum((U[edofMat]*KE).*U[edofMat],dims=2),nely,nelx,nelz)
            ce = reshape(sum((U1[edofMat]*KE).*U2[edofMat],dims=2),nely,nelx,nelz);
            
            #c = sum(sum(sum((Emin.+xPhys.^penal*(Emax-Emin)).*ce)))
            c  = U[dout,1]
            
            dc = penal*(Emax-Emin)*xPhys.^(penal-1).*ce
            dv = ones(nely,nelx,nelz)
            dc[:] = H*(dc[:]./Hs)
            dv[:] = H*(dv[:]./Hs)
            # OPTIMALITY CRITERIA UPDATE OF DESIGN VARIABLES AND PHYSICAL DENSITIES
            #l1 = 0; l2 = 1e9; move = 0.2; xnew = 0
            l1 = 0; l2 = 1e9; move = 0.1;xnew = 0
            #while (l2-l1)/(l1+l2) > 1e-3
            while (l2-l1)/(l1+l2) > 1e-4 && l2 > 1e-40
                lmid = 0.5*(l2+l1)
                #xnew = max.(0,max.(x.-move,min.(1,min.(x.+move,x.*sqrt.((0.0.-dc)./dv./lmid)))))
                xnew = max.(0,max.(x.-move,min.(1,min.(x.+move,x.*(max.(1e-10,-dc./dv./lmid)).^0.3))));

                xPhys[:] = (H*xnew[:])./Hs
                if sum(xPhys[:]) > volfrac*nelx*nely
                    l1 = lmid
                else
                    l2 = lmid
                end
            end
            change = maximum(abs.(xnew[:].-x[:]))
            x = xnew
            m=mean(xPhys[:])
            display(" It:$loop Obj:$c Vol:$m ch:$change ")
            if mod(loop,5)==0
                display(topplot3d(xPhys))
                topplot3d(xPhys)
                frame(anim)
            end

            xPhys = copy(x)
        end
    end
    return xPhys,anim
end

#############################################multimaterial############################################################

#Based on: https://link.springer.com/article/10.1007/s00158-013-0999-1
function multitop(nx,ny,tol_out,tol_f,iter_max_in,iter_max_out,p,q,e,v,rf)
    anim=Animation()
    alpha = zeros(Float64,nx*ny,p)
    for i = 1:p
        alpha[:,i] .= v[i]
    end
    
    # MAKE FILTER
    H,Hs = make_filter(nx,ny,rf)
    obj=0
    change_out = 2*tol_out; iter_out = 0;
    while (iter_out < iter_max_out) && (change_out > tol_out)
        alpha_old = copy(alpha)
        for a = 1:p
            for b = a+1:p
                obj,alpha = bi_top(a,b,nx,ny,p,v,e,q,alpha,H,Hs,iter_max_in);
            end
        end
        iter_out = iter_out + 1;
        change_out = norm(alpha[:].-alpha_old[:],Inf);
        display("Iter:$iter_out Obj.:$obj change:$change_out");
        #  UPDATE FILTER
        if (change_out < tol_f) && (rf>3)
            tol_f = 0.99*tol_f; rf = 0.99*rf; 
            H,Hs = make_filter(nx,ny,rf);
        end
        #  SCREEN OUT TEMPORAL TOPOLOGY EVERY 5 ITERATIONS
        if mod(iter_out,5)==0
            I = make_bitmap(p,nx,ny,alpha);
            display(RGB.(I[:,:,1],I[:,:,2],I[:,:,3]))
            I = permutedims(I, [3, 1, 2])
            img = colorview(RGB, I)
            heatmap(img,xaxis=nothing,yaxis=nothing,aspect_ratio=:equal)
            frame(anim)
        end
    end
    return anim,alpha
end

function bi_top(a,b,nx,ny,p,v,e,q,alpha_old,H,Hs,maxIter)
    alpha = copy(alpha_old)
    nu = 0.3;
    
    # PREPARE FINITE ELEMENT ANALYSIS
    A11 = [12 3 -6 -3; 3 12 3 0; -6 3 12 -3; -3 0 -3 12];
    A12 = [-6 -3 0 3; -3 -6 -3 -6; 0 -3 -6 3; 3 -6 3 -6];
    B11 = [-4 3 -2 9; 3 -4 -9 4; -2 -9 -4 -3; 9 4 -3 -4];
    B12 = [ 2 -3 4 -9; -3 2 9 -2; 4 9 2 3; -9 -2 3 2];
    KE = 1/(1-nu^2)/24*([A11 A12;A12' A11]+nu*[B11 B12;B12' B11]);
    
    nelx=nx
    nely=ny
    
    nodenrs = reshape(1:(1+nelx)*(1+nely),1+nely,1+nelx)
    edofVec = reshape(2*nodenrs[1:end-1,1:end-1].+1,nelx*nely,1)
    edofMat = repeat(edofVec,1,8).+repeat([0 1 2*nely.+[2 3 0 1] -2 -1],nelx*nely,1)
    iK = convert(Array{Int},reshape(kron(edofMat,ones(8,1))',64*nelx*nely,1))
    jK = convert(Array{Int},reshape(kron(edofMat,ones(1,8))',64*nelx*nely,1))
    
    # DEFINE LOADS AND SUPPORTS (HALF MBB-BEAM)
    F = sparse([2],[1],[-1.0],2*(nely+1)*(nelx+1),1)
    U = zeros(2*(nely+1)*(nelx+1),1)
    fixeddofs = union(1:2:2*(nely+1),2*(nelx+1)*(nely+1))
    alldofs = 1:(2*(nely+1)*(nelx+1))
    freedofs = setdiff(alldofs,fixeddofs)
    
    o=0;alpha_a=0
    # inner iteration
    for i =0: (maxIter-1)
        # FE-ANALYSIS
        E = e[1]*alpha[:,1].^q
        for phase = 2:p
            E = E + e[phase]*alpha[:,phase].^q;
        end

        sK = reshape(KE[:]*E[:]',64*nelx*nely,1)
        K = sparse(vec(iK),vec(jK),vec(sK)); K = (K+K')/2
        @timed U[freedofs] = K[freedofs,freedofs] \ Array(F[freedofs])
    

        # Objective function and sensitivity analysis
        ce = sum((U[edofMat]*KE).*U[edofMat],dims=2)
        o = sum(sum(E.*ce))
        
        # FILTERING OF SENSITIVITIES 
        dc = 0.0 .-(q .*(e[a].-e[b]).*alpha[:,a].^(q-1)).*ce;
        dc = H*(alpha[:,a].*dc)./Hs./max.(1e-3,alpha[:,a])
        dc = min.(dc,0.0)

        # UPDATE LOWER AND UPPER BOUNDS OF DESIGN VARIABLES
        move = 0.2;
        r = ones(nx*ny,1)
  
        for k = 1:p
            #if (k ~= a) && (k ~= b)
            if (k != a) && (k != b)
                # display("k $k a $a b $b")
                r = r .- alpha[:,k]
            end
        end
        l = max.(0,alpha[:,a] .-move)
        u = min.(r,alpha[:,a] .+move)
        # OPTIMALITY CRITERIA UPDATE OF DESIGN VARIABLES
        l1 = 0; l2 = 1e9
        while (l2-l1)/(l1+l2) > 1e-3
            lmid = 0.5*(l2+l1)
            alpha_a = max.(l,min.(u,alpha[:,a].*sqrt.(-dc./lmid)));
            if sum(alpha_a) > nx*ny*v[a]
                l1 = lmid
            else
                l2 = lmid 
            end
        end
        alpha[:,a] = alpha_a
        alpha[:,b] = r .-alpha_a

    end
    return o,alpha
end

function multitop_compliant(nx,ny,tol_out,tol_f,iter_max_in,iter_max_out,p,q,e,v,rf,Load,Support,Spring,DOut)
    anim=Animation()
    alpha = zeros(Float64,nx*ny,p)
    for i = 1:p
        alpha[:,i] .= v[i]
    end
    
    # MAKE FILTER
    H,Hs = make_filter(nx,ny,rf)
    obj=0
    change_out = 2*tol_out; iter_out = 0;
    while (iter_out < iter_max_out) && (change_out > tol_out)
        alpha_old = copy(alpha)
        for a = 1:p
            for b = a+1:p
                obj,alpha = bi_top_compliant(a,b,nx,ny,p,v,e,q,alpha,H,Hs,iter_max_in);
            end
        end
        iter_out = iter_out + 1;
        change_out = norm(alpha[:].-alpha_old[:],Inf);
        display("Iter:$iter_out Obj.:$obj change:$change_out");
        #  UPDATE FILTER
        if (change_out < tol_f) && (rf>3)
            tol_f = 0.99*tol_f; rf = 0.99*rf; 
            H,Hs = make_filter(nx,ny,rf);
        end
        #  SCREEN OUT TEMPORAL TOPOLOGY EVERY 5 ITERATIONS
        if mod(iter_out,5)==0
            I = make_bitmap_compliant(p,nx,ny,alpha);
            display(RGB.(I[:,:,1],I[:,:,2],I[:,:,3]))
            I = permutedims(I, [3, 1, 2])
            img = colorview(RGB, I)
            heatmap(img,xaxis=nothing,yaxis=nothing,aspect_ratio=:equal)
            frame(anim)
        end
    end
    return anim,alpha
end

function bi_top_compliant(a,b,nx,ny,p,v,e,q,alpha_old,H,Hs,maxIter,Load,Support,Spring,DOut)
    alpha = copy(alpha_old)
    nu = 0.3;
    
    # PREPARE FINITE ELEMENT ANALYSIS
    A11 = [12 3 -6 -3; 3 12 3 0; -6 3 12 -3; -3 0 -3 12];
    A12 = [-6 -3 0 3; -3 -6 -3 -6; 0 -3 -6 3; 3 -6 3 -6];
    B11 = [-4 3 -2 9; 3 -4 -9 4; -2 -9 -4 -3; 9 4 -3 -4];
    B12 = [ 2 -3 4 -9; -3 2 9 -2; 4 9 2 3; -9 -2 3 2];
    KE = 1/(1-nu^2)/24*([A11 A12;A12' A11]+nu*[B11 B12;B12' B11]);
    
    nelx=nx
    nely=ny
    
    nodenrs = reshape(1:(1+nelx)*(1+nely),1+nely,1+nelx)
    edofVec = reshape(2*nodenrs[1:end-1,1:end-1].+1,nelx*nely,1)
    edofMat = repeat(edofVec,1,8).+repeat([0 1 2*nely.+[2 3 0 1] -2 -1],nelx*nely,1)
    iK = convert(Array{Int},reshape(kron(edofMat,ones(8,1))',64*nelx*nely,1))
    jK = convert(Array{Int},reshape(kron(edofMat,ones(1,8))',64*nelx*nely,1))

    

    # # DEFINE LOADS AND SUPPORTS (HALF MBB-BEAM)
    # F = sparse([2],[1],[-1.0],2*(nely+1)*(nelx+1),1)
    # U = zeros(2*(nely+1)*(nelx+1),1)
    # fixeddofs = union(1:2:2*(nely+1),2*(nelx+1)*(nely+1))
    # alldofs = 1:(2*(nely+1)*(nelx+1))
    # freedofs = setdiff(alldofs,fixeddofs)

    # DEFINE LOADS AND SUPPORTS 
    F = sparse(2 .*Load[:,1] .-2 .+ Load[:,2],ones(size(Load,1)),Load[:,3],2*(nely+1)*(nelx+1),2)
    DofDOut = 2 * DOut[1] - 2 +DOut[2]; #only one
    F=Array(F)
    F[DofDOut,2]=-1
    fixeddofs = 2 .*Support[:,1] .-2 .+ Support[:,2]
    NSpring = size(Spring,1);
    s = sparse(2 .*Spring[:,1] .-2 .+ Spring[:,2],ones(size(Spring,1)),Spring[:,3],2*(nely+1)*(nelx+1),2)
    m=Array(s)[:,1]
    S= sparse(diagm(m))
    
    U = zeros(2*(nely+1)*(nelx+1),2)

    alldofs = 1:(2*(nely+1)*(nelx+1))
    freedofs = setdiff(alldofs,fixeddofs)
    
    o=0;alpha_a=0
    # inner iteration
    for i =0: (maxIter-1)
        # FE-ANALYSIS
        E = e[1]*alpha[:,1].^q
        for phase = 2:p
            E = E + e[phase]*alpha[:,phase].^q;
        end

        sK = reshape(KE[:]*E[:]',64*nelx*nely,1)


        K = sparse(vec(iK),vec(jK),vec(sK));
        K[din,din] = K[din,din] + 0.1;
        K[dout,dout] = K[dout,dout] + 0.1;
        K = (K+K')/2
        # @timed U[freedofs] = K[freedofs,freedofs] \ Array(F[freedofs])
        @timed U[freedofs,:] = K[freedofs,freedofs] \ Array(F[freedofs,:])
        U1=U[:,1]
        U2=U[:,2]


        # Objective function and sensitivity analysis
        # ce = sum((U[edofMat]*KE).*U[edofMat],dims=2)
        ce =-sum((U1[edofMat]*KE).*U2[edofMat],dims=2)
        # o = sum(sum(E.*ce))

        o=U[DofDOut,1]
        
        # FILTERING OF SENSITIVITIES 
        dc = 0.0 .-(q .*(e[a].-e[b]).*alpha[:,a].^(q-1)).*ce;
        dc = H*(alpha[:,a].*dc)./Hs./max.(1e-3,alpha[:,a])
        dc = min.(dc,0.0)

        # UPDATE LOWER AND UPPER BOUNDS OF DESIGN VARIABLES
        move=0.1;
        r = ones(nx*ny,1)
  
        for k = 1:p
            #if (k ~= a) && (k ~= b)
            if (k != a) && (k != b)
                # display("k $k a $a b $b")
                r = r .- alpha[:,k]
            end
        end
        l = max.(0,alpha[:,a] .-move)
        u = min.(r,alpha[:,a] .+move)
        # OPTIMALITY CRITERIA UPDATE OF DESIGN VARIABLES
        l1 = 0; l2 = 1e9
        while (l2-l1)/(l2+l1) > 1e-4 && l2>1e-40
        # while (l2-l1)/(l1+l2) > 1e-3
            lmid = 0.5*(l2+l1)
            alpha_a = max.(l,min.(u,alpha[:,a].*((max.(1e-10,-dc./lmid)).^0.3 )));

            if sum(alpha_a) > nx*ny*v[a]
                l1 = lmid
            else
                l2 = lmid 
            end
        end
        alpha[:,a] = alpha_a
        alpha[:,b] = r .-alpha_a

    end
    return o,alpha
end