Question

我正在尝试构建3D对象模型。但是我的代码只是渲染了图像中具有特定颜色的3D模型。

如何为每个表面（如魔方）创建具有6张图像的3D对象？

这是我的代码，使用Aspose 3D lib和C＃：

private void Form1_Load(object sender, EventArgs e)
{
    //Create a FBX file with embedded textures
    Scene scene = new Scene();
    scene.Open("BetterShirt.obj");
    //Create an embedded texture
    Texture tex = new Texture()
    {
        Content = CreateTextureContent(),
        FileName = "face.png",
        WrapModeU = Aspose.ThreeD.Shading.WrapMode.Wrap,
    };

    tex.SetProperty("TexProp", "value");
    //create a material with custom property
    //Aspose.ThreeD.Shading.
    Material mat = scene.RootNode.ChildNodes[0].Material;
    mat.SetTexture(Material.MapDiffuse, tex);
    mat.SetProperty("MyProp", 1.0);

    scene.RootNode.ChildNodes[0].Material = mat;
    //save this to file
    scene.Save("exported.obj", FileFormat.WavefrontOBJ);
}

private static byte[] CreateTextureContent()
{
    using (var bitmap = new Bitmap(256, 256))
    {
        using (var g = Graphics.FromImage(bitmap))
        {
            g.Clear(Color.White);
            LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, 128, 128),
                Color.Moccasin, Color.Blue, 45);
            using (var font = new Font(FontFamily.GenericSerif, 40))
            {
                g.DrawString("Aspose.3D", font, brush, Point.Empty);
            }
        }
        using (var ms = new MemoryStream())
        {
            //bitmap.Save(ms, ImageFormat.Png);
            return ms.ToArray();
        }
    }
}

用6张图像构建3D对象模型

Answer 1

我们根据您的要求设计了以下代码。评论也已添加，供您参考。请尝试在您的环境中使用它，然后与我们分享您的反馈。

    private static void RubikCube()
    {
        Bitmap[] bitmaps = CreateRubikBitmaps();
        Scene scene = new Scene();
        //create a box and convert it to mesh, so we can manually specify the material per face
        var box = (new Box()).ToMesh();

        //create a material mapping, the box mesh generated from Box primitive class contains 6 polygons, then we can reference the material of polygon(specified by MappingMode.Polygon) by index(ReferenceMode.Index)
        var materials = (VertexElementMaterial)box.CreateElement(VertexElementType.Material, MappingMode.Polygon, ReferenceMode.Index);
        //and each polygon uses different materials, the indices of these materials are specified below
        materials.SetIndices(new int[] {0, 1, 2, 3, 4, 5});
        //create the node and materials(referenced above)
        var boxNode = scene.RootNode.CreateChildNode(box);
        for (int i = 0; i < bitmaps.Length; i++)
        {
            //create material with texture
            var material = new LambertMaterial();
            var tex = new Texture();
            using (var ms = new MemoryStream())
            {
                bitmaps[i].Save(ms, ImageFormat.Png);
                var bytes = ms.ToArray();
                //Save it to Texture.Content as embedded texture, thus the scene with textures can be exported into a single FBX file.
                tex.Content = bytes;
                //Give it a name and save it to disk so it can be opened with .obj file 
                tex.FileName = string.Format("cube_{0}.png", i);
                File.WriteAllBytes(tex.FileName, bytes);
                //Dispose the bitmap since we're no longer need it.
                bitmaps[i].Dispose();
            }
            //the texture is used as diffuse
            material.SetTexture(Material.MapDiffuse, tex);
            //attach it to the node where contains the box mesh
            boxNode.Materials.Add(material);
        }
        //save it to file

        //3D viewer of Windows 10 does not support multiple materials, you'll see same textures in each face, but the tools from Autodesk does
        scene.Save("test.fbx", FileFormat.FBX7500ASCII);
        //NOTE: Multiple materials of mesh in Aspose.3D's OBJ Exporter is not supported yet.
        //But we can split the mesh with multiple materials into different meshes by using PolygonModifier.SplitMesh
        PolygonModifier.SplitMesh(scene, SplitMeshPolicy.CloneData);
        //following code will also generate a material library file(test.mtl) which uses the textures exported in above code.
        scene.Save("test.obj", FileFormat.WavefrontOBJ);
    }

    private static Bitmap[] CreateRubikBitmaps()
    {
        Brush[] colors = { Brushes.White, Brushes.Red, Brushes.Blue, Brushes.Yellow, Brushes.Orange, Brushes.Green};
        Bitmap[] bitmaps = new Bitmap[6];
        //initialize the cell colors
        int[] cells = new int[6 * 9];
        for (int i = 0; i < cells.Length; i++)
        {
            cells[i] = i / 9;
        }
        //shuffle the cells
        Random random = new Random();
        Array.Sort(cells, (a, b) => random.Next(-1, 2));
        //paint each face

        // size of each face is 256px
        const int size = 256;
        // size of cell is 80x80 
        const int cellSize = 80;
        // calculate padding size between each cell
        const int paddingSize = (size - cellSize * 3) / 4;
        int cellId = 0;
        for (int i = 0; i < 6; i++)
        {
            bitmaps[i] = new Bitmap(size, size, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
            using (Graphics g = Graphics.FromImage(bitmaps[i]))
            {
                g.Clear(Color.Black);
                for (int j = 0; j < 9; j++)
                {
                    //calculate the cell's position
                    int row = j / 3;
                    int column = j % 3;
                    int y = row * (cellSize + paddingSize) + paddingSize;
                    int x = column * (cellSize + paddingSize) + paddingSize;
                    Brush cellBrush = colors[cells[cellId++]];
                    //paint cell
                    g.FillRectangle(cellBrush, x, y, cellSize, cellSize);
                }
            }
        }
        return bitmaps;
    }

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如何使用Aspose 3D库构建自定义的3D对象建模

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