ControlWindow.xaml

<Window x:Class="Lab.ControlWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Lab"
        mc:Ignorable="d"
        Title="ControlWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <Border BorderThickness="5,5,5,5" BorderBrush="LightGray" Grid.Row="0" Grid.Column="0">
            <Grid x:Name="controlPanel">
                <Grid.RowDefinitions>
                    <RowDefinition></RowDefinition>
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                </Grid.ColumnDefinitions>
                <Button x:Name="updateButton" Grid.Column="6" Click="UpdateButtonClickHandler">Test</Button>
            </Grid>
        </Border>
        <Border x:Name="viewportBorder" Background="White" Grid.Row="1" Grid.Column="0">
            <Viewport3D x:Name="viewport" Grid.Row="0" Grid.Column="0" IsHitTestVisible="False"></Viewport3D>
        </Border>
    </Grid>
</Window>