Add support for materials in obj files

src/io/obj.jl

@@ -4,59 +4,104 @@
 #
 ##############################
 
-function load(io::Stream{format"OBJ"}; facetype=GLTriangleFace,
+function load(fn::File{format"OBJ"}; facetype=GLTriangleFace,
         pointtype=Point3f, normaltype=Vec3f, uvtype=Any)
 
+    function parse_bool(x)
+        if lowercase(x) == "off" || x == "0"
+            return false
+        elseif lowercase(x) == "on" || x == "1"
+            return true
+        else
+            error("Failed to parse $x as Bool.")
+        end
+    end
+
     points, v_normals, uv, faces = pointtype[], normaltype[], uvtype[], facetype[]
     f_uv_n_faces = (faces, facetype[], facetype[])
 
-    for full_line in eachline(stream(io))
-        # read a line, remove newline and leading/trailing whitespaces
-        line = strip(chomp(full_line))
-        !isascii(line) && error("non valid ascii in obj")
-
-        if !startswith(line, "#") && !isempty(line) && !all(iscntrl, line) #ignore comments
-            lines = split(line)
-            command = popfirst!(lines) #first is the command, rest the data
-
-            if "v" == command # mesh always has vertices
-                push!(points, pointtype(parse.(eltype(pointtype), lines)))
-            elseif "vn" == command
-                push!(v_normals, normaltype(parse.(eltype(normaltype), lines)))
-            elseif "vt" == command
-                if length(lines) == 2
-                    if uvtype == Any
-                        uvtype = Vec2f
-                        uv = uvtype[]
+    # name => (first_face, value)
+    group_meta = Dict{Symbol, Dict{Int, T} where T}()
+    mtllibs = String[]
+
+    open(fn) do io
+        skipmagic(io)
+
+        for full_line in eachline(stream(io))
+            # read a line, remove newline and leading/trailing whitespaces
+            line = strip(chomp(full_line))
+            !isascii(line) && error("non valid ascii in obj")
+
+            if !startswith(line, "#") && !isempty(line) && !all(iscntrl, line) #ignore comments
+                lines = split(line)
+                command = popfirst!(lines) #first is the command, rest the data
+
+                if "v" == command # mesh always has vertices
+                    push!(points, pointtype(parse.(eltype(pointtype), lines)))
+
+                elseif "vn" == command
+                    push!(v_normals, normaltype(parse.(eltype(normaltype), lines)))
+
+                elseif "vt" == command
+                    if length(lines) == 2
+                        if uvtype == Any
+                            uvtype = Vec2f
+                            uv = uvtype[]
+                        end
+                        push!(uv, Vec{2,eltype(uvtype)}(parse.(eltype(uvtype), lines)))
+                    elseif length(lines) == 3
+                        if uvtype == Any
+                            uvtype = Vec3f
+                            uv = uvtype[]
+                        end
+                        push!(uv, Vec{3,eltype(uvtype)}(parse.(eltype(uvtype), lines)))
+                    else
+                        error("Unknown UVW coordinate: $lines")
                     end
-                    push!(uv, Vec{2,eltype(uvtype)}(parse.(eltype(uvtype), lines)))
-                elseif length(lines) == 3
-                    if uvtype == Any
-                        uvtype = Vec3f
-                        uv = uvtype[]
+
+                elseif "f" == command # mesh always has faces
+
+                    if any(x-> occursin("//", x), lines)
+                        fs = process_face_normal(lines)
+                    elseif any(x-> occursin("/", x), lines)
+                        fs = process_face_uv_or_normal(lines)
+                    else
+                        append!(faces, triangulated_faces(facetype, lines))
+                        continue
                     end
-                    push!(uv, Vec{3,eltype(uvtype)}(parse.(eltype(uvtype), lines)))
-                else
-                    error("Unknown UVW coordinate: $lines")
-                end
-            elseif "f" == command # mesh always has faces
-                if any(x-> occursin("//", x), lines)
-                    fs = process_face_normal(lines)
-                elseif any(x-> occursin("/", x), lines)
-                    fs = process_face_uv_or_normal(lines)
+                    for i = 1:length(first(fs))
+                        append!(f_uv_n_faces[i], triangulated_faces(facetype, getindex.(fs, i)))
+                    end
+
+                elseif "s" == command  # Blender sets this just before faces
+                    shadings = get!(() -> Dict{Int, Bool}(), group_meta, :shading)
+                    shadings[length(faces)+1] = parse_bool(lines[1])
+
+                elseif "o" == command  # Blender sets this before vertices
+                    objects = get!(() -> Dict{Int, String}(), group_meta, :object)
+                    objects[length(faces)+1] = join(lines, ' ')
+
+                elseif "g" == command
+                    groups = get!(() -> Dict{Int, String}(), group_meta, :groups)
+                    groups[length(faces)+1] = join(lines, ' ')
+
+                elseif "mtllib" == command
+                    push!(mtllibs, join(lines, ' '))
+
+                elseif "usemtl" == command # Blender sets this just before faces
+                    materials = get!(() -> Dict{Int, String}(), group_meta, :material_names)
+                    materials[length(faces)+1] = join(lines, ' ')
                 else
-                    append!(faces, triangulated_faces(facetype, lines))
-                    continue
+                    # TODO:
+                    # parameter space vertices
+                    # line elements?
                 end
-                for i = 1:length(first(fs))
-                    append!(f_uv_n_faces[i], triangulated_faces(facetype, getindex.(fs, i)))
-                end
-            else
-                #TODO
             end
         end
+
     end
 
+    # Generate base mesh
     if !isempty(f_uv_n_faces[2]) && (f_uv_n_faces[2] != faces)
         uv = FaceView(uv, f_uv_n_faces[2])
     end
@@ -65,11 +110,62 @@ function load(io::Stream{format"OBJ"}; facetype=GLTriangleFace,
         v_normals = FaceView(v_normals, f_uv_n_faces[3])
     end
 
-    return GeometryBasics.mesh(
+    mesh = GeometryBasics.mesh(
         points, faces, facetype = facetype; 
         uv = isempty(uv) ? nothing : uv, 
         normal = isempty(v_normals) ? nothing : v_normals
     )
+
+    if !isempty(group_meta)
+
+        # Find all the starting indices used across objects, groups, shadings, materials
+        starts_set = Set{Int}()
+        for meta in values(group_meta)
+            union!(starts_set, keys(meta))
+        end
+        starts_vec = sort!(collect(starts_set))
+
+        # generate views
+        resize!(mesh.views, length(starts_vec))
+        for i in 1:length(starts_vec)-1
+            mesh.views[i] = starts_vec[i] : starts_vec[i+1]-1
+        end
+        mesh.views[end] = starts_vec[end] : length(faces)
+
+        # generate metadata dict matching the views with nothing as the gap filler
+        N = length(starts_vec)
+        metadata = Dict{Symbol, Any}()
+        for (name, dict) in group_meta
+            if length(dict) == N
+                metadata[name] = getindex.(Ref(dict), starts_vec)
+            else
+                metadata[name] = get.(Ref(dict), starts_vec, nothing)
+            end
+        end
+
+        # Load material files
+        materials = Dict{String, Dict{String, Any}}()
+        path = joinpath(splitpath(FileIO.filename(fn))[1:end-1])
+        for filename in mtllibs
+            try
+                _load_mtl!(materials, joinpath(path, filename))
+            catch e
+                @error "While parsing $(joinpath(path, filename)):" exception = e
+            end
+        end
+        metadata[:materials] = materials
+
+        return MetaMesh(mesh, metadata)
+
+    else
+        # TODO: Should we have different output types here?
+        return mesh
+
+        # views = UnitRange{Int}[]
+        # metadata = Dict{Symbol, Any}()
+    end
+
+    return MetaMesh(mesh, metadata)
 end
 
 # of form "faces v1 v2 v3 ....""
@@ -116,3 +212,188 @@ function save(f::Stream{format"OBJ"}, mesh::AbstractMesh)
         println(io, "f ", join(convert.(Int, f), " "))
     end
 end
+
+
+function _load_mtl!(materials::Dict{String, Dict{String, Any}}, filename::String)
+    endswith(filename, ".mtl") || error("Material Template Library $filename must be a .mtl file.")
+
+
+    name_lookup = Dict(
+        "Ka" => "ambient", "Kd" => "diffuse", "Ks" => "specular",
+        "Ns" => "shininess", "d" => "alpha", "Tr" => "transmission", # 1 - alpha
+        "Ni" => "refractive index", "illum" => "illumination model",
+        # PBR
+        "Pr" => "roughness", "Pm" => "metallic", "Ps" => "sheen", 
+        "Pc" => "clearcoat thickness", "Pcr" => "clearcoat roughness", 
+        "Ke" => "emissive", "aniso" => "anisotropy", 
+        "anisor" => "anisotropy rotation", 
+        "Tf" => "transmission filter",
+        # texture maps
+        "map_Ka" => "ambient map",  "map_Kd" => "diffuse map", 
+        "map_Ks" => "specular map", "map_Ns" => "shininess map", 
+        "map_d" => "alpha map", "map_Tr" => "transmission map",
+        "map_bump" => "bump map", "bump" => "bump map",
+        "disp" => "displacement map", "decal" => "decal map",
+        "refl" => "reflection map", "norm" => "normal map",
+        "map_Pr" => "roughness map", "map_Pm" => "metallic map", 
+        "map_Ps" => "sheen map", "map_Ke" => "emissive map",
+        "map_RMA" => "roughness metalness occlusion map",
+        "map_ORM" => "occlusion roughness metalness map",
+    )
+
+    path = joinpath(splitpath(filename)[1:end-1])
+    open(filename, "r") do file
+
+        # Just so the variable is defined
+        material = Dict{String, Any}()
+
+        for full_line in eachline(file)
+            # read a line, remove newline and leading/trailing whitespaces
+            line = strip(chomp(full_line))
+            !isascii(line) && error("non valid ascii in obj")
+
+            if !startswith(line, "#") && !isempty(line) && !all(iscntrl, line) #ignore comments
+                lines = split(line)
+                command = popfirst!(lines) #first is the command, rest the data
+
+                if command == "newmtl"
+                    name = join(lines, ' ')
+                    materials[name] = material = Dict{String, Any}()
+
+                elseif command == "Ka" || command == "Kd" || command == "Ks"
+                    material[name_lookup[command]] = Vec3f(parse.(Float32, lines)...)
+
+                elseif command == "Ns" || command == "Ni" || command == "Pr" ||
+                        command == "Pm" || command == "Ps" || command == "Pc" ||
+                        command == "Pcr" || command == "Ke" || command == "aniso" ||
+                        command == "anisor" || command == "Tf"
+
+                    material[name_lookup[command]] = parse.(Float32, lines[1])
+
+                elseif command == "d"
+                    alpha = parse.(Float32, lines[1])
+                    if haskey(material, "alpha") && !(material["alpha"] ≈ alpha)
+                        @error("Material alpha doubly defined. Overwriting $(material["alpha"]) with $alpha.")
+                    end
+                    material[name_lookup[command]] = alpha
+
+                elseif command == "Tr"
+                    alpha = 1f0 - parse.(Float32, lines[1])
+                    if haskey(material, "alpha") && !(material["alpha"] ≈ alpha)
+                        @error("Material alpha doubly defined. Overwriting $(material["alpha"]) with $alpha")
+                    end
+                    material[name_lookup["d"]] = alpha
+
+                # elseif Tf # transmission filter
+
+                elseif command == "illum"
+                    # See https://en.wikipedia.org/wiki/Wavefront_.obj_file#Basic_materials
+                    material[name_lookup[command]] = parse.(Int, lines[1])
+
+                elseif startswith(command, "map") || command == "bump" || command == "norm" ||
+                        command == "refl" || command == "disp" || command == "decal"
+
+                    # TODO: treat all the texture options
+                    material[get(name_lookup, command, command)] = parse_texture_info(path, lines)
+
+                else
+                    material[command] = lines
+                end
+            end
+        end
+
+    end
+
+    return materials
+end
+
+# TODO: Consider generating a ShaderAbstractions Sampler?
+function parse_texture_info(parent_path::String, lines::Vector{SubString{String}})
+    idx = 1
+    output = Dict{String, Any}()
+    name_lookup = Dict(
+        "o" => "offset", "s" => "scale", "t" => "turbulence",
+        "blendu" => "blend horizontal", "blendv" => "blend vertical",
+        "boost" => "mipmap sharpness", "bm" => "bump multiplier"
+    )
+
+    function parse_bool(x, default)
+        if lowercase(x) == "off" || x == "0"
+            return false
+        elseif lowercase(x) == "on" || x == "1"
+            return true
+        else
+            error("Failed to parse $x as Bool.")
+        end
+    end
+
+    while idx < length(lines) + 1
+        if startswith(lines[idx], '-')
+            command = lines[idx][2:end]
+
+            if command == "blendu" || command == "blendv"
+                name = name_lookup[command]
+                output[name] = parse_bool(lines[idx+1], true)
+                idx += 2
+
+            elseif command == "boost" || command == "bm"
+                output[name_lookup[command]] = parse(Float32, lines[idx+1])
+                idx += 2
+
+            elseif command == "mm"
+                output["brightness"] = parse(Float32, lines[idx+1])
+                output["contrast"]   = parse(Float32, lines[idx+2])
+                idx += 3
+
+            elseif command == "o" || command == "s" || command == "t"
+                default = command == "s" ? 1f0 : 0f0
+                x = parse(Float32, lines[idx+1])
+                y = length(lines) >= idx+2 ? tryparse(Float32, lines[idx+2]) : nothing
+                z = length(lines) >= idx+3 ? tryparse(Float32, lines[idx+3]) : nothing
+                output[name_lookup[command]] = Vec3f(
+                    x, something(y, default), something(z, default)
+                )
+                idx += 2 + (y !== nothing) + (z !== nothing)
+
+            elseif command == "texres" # is this only one value?
+                output["resolution"] = parse(Float32, lines[idx+1])
+                idx += 2
+
+            elseif command == "clamp"
+                output["clamp"] = parse_bool(lines[idx+1])
+                idx += 2
+
+            elseif command == "imfchan"
+                output["channel"] = lines[idx+1]
+                idx += 2
+
+            elseif command == "type"
+                output[command] = lines[idx+1]
+                idx += 2
+
+            # TODO: PBR tags
+
+            else
+                @warn "Failed to parse -$command"
+                idx += 1
+            end
+        else
+            filepath = joinpath(parent_path, lines[idx])
+            i = idx+1
+            while i <= length(lines) && !startswith(lines[i], '-')
+                filepath = filepath * ' ' * lines[i]
+                i += 1
+            end
+            filepath = replace(filepath, "\\\\" => "/")
+            filepath = replace(filepath, "\\" => "/")
+            if isfile(filepath) || endswith(lowercase(filepath), r"\.(png|jpg|jpeg|tiff|bmp)")
+                output["filename"] = filepath
+                idx = i
+            else
+                idx += 1
+            end
+        end
+    end
+
+    return output
+end