Script32_MeshCompare.lua

-- Lua example for Autodesk Netfabb 2021.0

-- Compares two selected meshes, displays the mesh distances in a histogram, and generates part copies
-- to visuzalize with colors the distances of one mesh vs the other, respectively, based on the selected distance bin. 

local insertMeshesIntoTable
insertMeshesIntoTable = function(meshgroup, Outtable)
    for mesh_index = 0, meshgroup.meshcount - 1 do
        local traymesh = meshgroup:getmesh(mesh_index)
        table.insert(Outtable, traymesh)
    end
    for group_index = 0, meshgroup.groupcount - 1 do
        subgroup = meshgroup:getsubgroup(group_index)
        insertMeshesIntoTable(subgroup, Outtable)
    end
end

dialog = nil
histogram = nil
image = nil
edit_select1 = nil
edit_select2 = nil
distances1 = system:createarray()
distances2 = system:createarray()
copy1 = nil
copy2 = nil

function SelectDistance()
    -- select bar in graph and update image
    histogram:selectatpixel(image.width, image.height, image.mousex, image.mousey)
    local histogram_image = histogram:drawhistogram(image.width, image.height)
    image:setimage(histogram_image)

    edit_select1.text = string.format("%.2f mm", histogram.selectionstart)
    edit_select2.text = string.format("%.2f mm", histogram.selectionend)
end

function DoCancel()
    if dialog ~= nil then
        dialog:close(false)
    end
end

function ColorMesh(mesh, distances)
    local nodeindices = system:createarray()
    local theshold = histogram.selectionstart
    mesh:gettrianglenodeindices(nodeindices)
    mesh:colortriangles(128, 128, 128, 128)
    for i = 0, mesh.facecount - 1 do
        for j = 0, 2 do
            index = nodeindices:get(i * 3 + j)
            dist = distances:get(index)
            if dist > theshold then
                mesh:colortriangle(i, 0, 0, 255, 254)
            end
            if dist < -theshold then
                mesh:colortriangle(i, 255, 0, 0, 254)
            end
        end
    end
end

function PaintMesh()
    ColorMesh(copy1, distances1)
    ColorMesh(copy2, distances2)

    local root = tray.root
    newtraymesh = root:addmesh(copy1)
    newtraymesh.name = "meshcompare 1"
    newtraymesh = root:addmesh(copy2)
    newtraymesh.name = "meshcompare 2"
    DoCancel()
end

function CompareShowDistances(mesh1, mesh2)
    -- Get meshes with applied matrix
    luamesh1 = mesh1.mesh
    luamesh2 = mesh2.mesh
    copy1 = luamesh1:dupe()
    copy2 = luamesh2:dupe()
    copy1:applymatrix(mesh1.matrix)
    copy2:applymatrix(mesh2.matrix)

    -- Do comparison, get distances
    copy1:comparegetdistances(copy2, distances1, distances2)

    -- Create histogram by distances
    histogram = system:createhistogram()
    histogram.caption_x = "Distance"
    histogram.caption_y = "Occurence"
    histogram.bar_count = 25
    histogram.unit = " mm"
    hausdorff = 0
    for i = 0, distances1.length - 1 do
        local dist = math.abs(distances1:get(i))
        hausdorff = math.max(hausdorff, dist)
        histogram:addvalue(dist)
    end
    for i = 0, distances2.length - 1 do
        local dist = math.abs(distances2:get(i))
        hausdorff = math.max(hausdorff, dist)
        histogram:addvalue(dist)
    end

    dialog = application:createdialog()
    dialog.caption = "Mesh comparison"
    dialog.width = 500
    dialog.translatecaption = false
    local groupbox = dialog:addgroupbox()
    groupbox.caption = ""
    groupbox.translate = false

    local edit = groupbox:addedit()
    edit.caption = "Mesh 1"
    edit.captionwidth = 150
    edit.text = mesh1.name
    edit.translate = false
    edit.enabled = false

    local edit = groupbox:addedit()
    edit.caption = "Mesh 2"
    edit.captionwidth = 150
    edit.text = mesh2.name
    edit.translate = false
    edit.enabled = false

    local edit = groupbox:addedit()
    edit.caption = "Hausdorff distance"
    edit.captionwidth = 150
    edit.text = string.format("%.2f mm", hausdorff)
    edit.translate = false
    edit.enabled = false

    edit_select1 = groupbox:addedit()
    edit_select1.caption = "Selection start"
    edit_select1.captionwidth = 150
    edit_select1.text = "---"
    edit_select1.translate = false
    edit_select1.enabled = false

    edit_select2 = groupbox:addedit()
    edit_select2.caption = "Selection end"
    edit_select2.captionwidth = 150
    edit_select2.text = "---"
    edit_select2.translate = false
    edit_select2.enabled = false

    image = groupbox:addimage()
    image.width = dialog.width - 15
    image.height = 300
    local histogram_image = histogram:drawhistogram(image.width, image.height)
    image:setimage(histogram_image)
    image.onclick = "SelectDistance"

    local splitter = groupbox:addsplitter()
    splitter:settoleft()
    local button = splitter:addbutton()
    button.caption = "Paint mesh"
    button.translate = false
    button.onclick = "PaintMesh"

    splitter:settoright()
    button = splitter:addbutton()
    button.caption = "Cancel"
    button.translate = false
    button.onclick = "DoCancel"

    dialog:show()
end

system:setloggingtooglwindow(true)
root = tray.root
-- Collect meshes in the tray
local meshes = {}
insertMeshesIntoTable(root, meshes)
mesh1 = nil
mesh2 = nil
-- Iterate meshes in group
for i, traymesh in pairs(meshes) do
    local luamesh = traymesh.mesh
    if traymesh.selected then
        if mesh1 == nil then
            mesh1 = traymesh
        elseif mesh2 == nil then
            mesh2 = traymesh
        end
    end
end
if (mesh1 == nil) or (mesh2 == nil) then
    system:log("Please select two meshes!")
else
    CompareShowDistances(mesh1, mesh2)
end