Mipmapping in wpf

Question

I'm new to 'wpf' and I've come over the following problem: In my project I try to use small resolution .png as texture for a model. When I disable mipmapping in Blender (where I built the cube) the result is just what I want:

no mipmapping

But in the wpf project the blurred effect never turns off:

wpf result

Here is my code:

<Window x:Class="GCS.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="504" Width="525" ShowInTaskbar="True">
<Grid>
        <Viewport3D Name="myViewport"
            xmlns="http://schemas.microsoft.com/netfx/2007/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
            <Viewport3D.Resources>
                <MaterialGroup x:Key="Material">
                    <DiffuseMaterial>
                        <DiffuseMaterial.Brush>
                            <ImageBrush RenderOptions.BitmapScalingMode="NearestNeighbor" ViewportUnits="Absolute" ImageSource="char.png"/>
                        </DiffuseMaterial.Brush>
                    </DiffuseMaterial>
                </MaterialGroup>
            </Viewport3D.Resources>
            <Viewport3D.Camera>
                <PerspectiveCamera Position="7.8,-11,-0.8" NearPlaneDistance="1" FarPlaneDistance="50" LookDirection="-0.4,0.9,-0.3" UpDirection="0,0,1" FieldOfView="15"/>
            </Viewport3D.Camera>
            <Viewport3D.Children>
                <ModelVisual3D>
                    <ModelVisual3D.Content>
                        <Model3DGroup>
                            <GeometryModel3D Material="{StaticResource Material}">
                                <GeometryModel3D.Transform>
                                    <Transform3DGroup>
                                        <TranslateTransform3D OffsetZ="0" OffsetX="0" OffsetY="-7"/>
                                        <ScaleTransform3D ScaleZ="1" ScaleY="1" ScaleX="1"/>
                                        <RotateTransform3D>
                                            <RotateTransform3D.Rotation>
                                                <AxisAngleRotation3D Axis="1,0,0" Angle="92"/>
                                            </RotateTransform3D.Rotation>
                                        </RotateTransform3D>
                                        <TranslateTransform3D OffsetZ="0" OffsetX="0" OffsetY="7"/>
                                        <TranslateTransform3D OffsetZ="-6.622" OffsetX="0" OffsetY="-0.023"/>
                                    </Transform3DGroup>
                                </GeometryModel3D.Transform>
                                <GeometryModel3D.Geometry>
                                    <MeshGeometry3D
                                        Normals="-1,0,0 -1,0,0 -1,0,0 -1,0,0 0,0,-1 0,0,-1 0,0,-1 0,0,-1 1,0,0 1,0,0 1,0,0 1,0,0 0,0,1 0,0,1 0,0,1 0,0,1 0,-1,0 0,-1,0 0,-1,0 0,-1,0 0,1,0 0,1,0 0,1,0 0,1,0"
                                        Positions="-1,6,-1 -1,6,1 -1,8,1 -1,8,-1 -1,8,-1 1,8,-1 1,6,-1 -1,6,-1 1,8,-1 1,8,1 1,6,1 1,6,-1 -1,6,1 1,6,1 1,8,1 -1,8,1 -1,6,1 -1,6,-1 1,6,-1 1,6,1 1,8,1 1,8,-1 -1,8,-1 -1,8,1"
                                        TextureCoordinates="0,0.5 0.125,0.5 0.125,0.25 0,0.25 0.5,0.25 0.375,0.25 0.375,0.5 0.5,0.5 0.375,0.25 0.25,0.25 0.25,0.5 0.375,0.5 0.125,0.5 0.25,0.5 0.25,0.25 0.125,0.25 0.375,0.25 0.375,0 0.25,0 0.25,0.25 0.25,0.25 0.25,0 0.125,0 0.125,0.25"
                                        TriangleIndices="0 1 2 0 2 3 4 5 6 4 6 7 8 9 10 8 10 11 12 13 14 12 14 15 16 17 18 16 18 19 20 21 22 20 22 23"/>
                                </GeometryModel3D.Geometry>
                            </GeometryModel3D>
                        </Model3DGroup>
                    </ModelVisual3D.Content>
                </ModelVisual3D>
                <ModelVisual3D>
                    <ModelVisual3D.Content>
                        <AmbientLight Color="#ffffff"/>
                    </ModelVisual3D.Content>
                </ModelVisual3D>
            </Viewport3D.Children>
        </Viewport3D>
</Grid>

I've done a lot of search on the Internet and tried many approaches: enforced software rendering, used DrawingBrush instead of ImageBrush but the result is the same. Is there any way to overcome such rendering?

Dykes

You are setting RenderOptions.BitmapScalingMode on the ImgaeBrush. I don't know whether this is the solution (hence a comment rather than an answer), but you can also set it on the GeometryModel3D, ModelVisual3D and ViewPort3D, as well as the Window and the Grid. Have you tried any / all of these options to see if it makes a difference? It seems possible to me that the ImageBrush itself doesn't actually do the scaling in a 3D scenario and therefore setting RenderOptions on the brush object won't have the desired effect. – Noble

Thanks for a response. In fact I tried all of these variants by one and even together. The result is the same ((( – Dykes

Ah - out of ideas then! My guess is that the rendering is being done by the 3D hardware in your graphics card, over which WPF apparently has less control than we might like. That really is a guess, though and I've no idea how or even whether it's possible to override it if that is the case. Long shot, but are your video card drivers up to date? – Noble

Did you try this: <ImageBrush RenderOptions.BitmapScalingMode="HighQuality" ... – Cytherea

Provide the image to make the code above executable so we can play with it. – Streptomycin

Answer 1

Try the following approach using VisualBrush - it produces clear, aliased texturing:

        <DiffuseMaterial x:Key="Material">
            <DiffuseMaterial.Brush>
                <VisualBrush RenderOptions.CachingHint="Cache">
                    <VisualBrush.Visual>
                        <Image Source="char.png" RenderOptions.BitmapScalingMode="NearestNeighbor" />
                    </VisualBrush.Visual>
                </VisualBrush>
            </DiffuseMaterial.Brush>
        </DiffuseMaterial>
    </Grid.Resources>


    <Viewport3D Name="myViewport">
        <Viewport3D.Camera>
            <PerspectiveCamera Position="0 0.5 1.5" LookDirection="0 0 -1"
                           UpDirection="0 1 0" FieldOfView="120" />
        </Viewport3D.Camera>
        <Viewport3D.Children>
            <ModelVisual3D>
                <ModelVisual3D.Content>
                    <GeometryModel3D Material="{StaticResource Material}">

                        <GeometryModel3D.Geometry>
                            <MeshGeometry3D
                         Positions="0 0 0, 0 1 0, 1 0 0, 1 1 0"
                         TriangleIndices="0 2 3, 0 3 1"
                         TextureCoordinates="0 1, 0 0, 1 1, 1 0" />
                        </GeometryModel3D.Geometry>

                    </GeometryModel3D>
                </ModelVisual3D.Content>
            </ModelVisual3D>

            <ModelVisual3D>
                <ModelVisual3D.Content>
                    <AmbientLight Color="#ffffff"/>
                </ModelVisual3D.Content>
            </ModelVisual3D>
        </Viewport3D.Children>
    </Viewport3D>
</Grid>

Eada