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C#, display and navigate structural 3D FEM model (helix-toolkit, SharpDX?)

Hello! I am trying to implement a simple way to display the deformed shape of a beam. I found HelixToolkit that offers perfect tools, but I can't find the way to display different tiles of the same mesh with a different colour, or gradient. I found this: https://github.com/helix-toolkit/helix-toolkit/issues/885 that is the adding of the VertColorMaterial property, but it looks like it is for SharpDX library, but I started with HelixToolkit wpf (don't understand if in HelixToolkit is also available).
I can't even find a way to do it with SharpDX: it looks that there is almost no doc in internet.
Additionaly, SharpDX stopped its developement.
So:
do you know any example?
do you suggest me another library, which is fast/offers the ability of navigate the model, and it is compatible/use the wpf framework?
I also would like the ability to refine and subdivide a mesh.
Any kind of advice would be useful, I am new to the world of computer 3d graphic.
Thanks
EDIT 1:
I followed JonasH hint applying a texture, but it apply the texture for each tile. (See image).
I can only dinstict by out materian and in materia (set in the picture as Hue and the arrow Texture).
I need to apply one color for each polygon to give to the mesh a "FEM" style. Do you know how is it possibile with HelixToolkit?

You might consider using Kitware VTK instead of HelixToolkit. It’s extremely powerful library for scientific data visualization, well documented, perfect for finite element pre and post processing. You can take a look on my app, unfortunately it has not been documented yet, but just as an example:
https://github.com/galuszkm/STAN

I assume you have a color per vertex you want to use. I would recommend using wpf or helixToolkit wpf since they are quite easy to use. But as far as I'm aware they do not support vertex coloring.
A workaround would be to use a texture. I would assume you want to visualize some scalar property as a color. You would first need to create your MeshGeometry and assign the TextureCoordinates, simply assign the value you want to visualize to one of the texture coordinates in the 0-1 range. You would also need to create a gradient texture, either a gradientBrush or create an image. You would then assign the brush like:
var brush = new ImageBrush()
{
ImageSource = new BitmapImage(new Uri("gradient.png", UriKind.Relative))
};
var material = new DiffuseMaterial(brush);
GeometryModel3D model = new GeometryModel3D(mesh, material);

How to make graphics (Shape, animation) in c#

How to make a circle with text inside ?? then move it from one location to another, and then access it later (to delete it).
I want to make something like this

Your question is really very broad and you got a few nice links you should study to learn all about GDI+ drawing.
But if taken literally there is a slightly exotic alternative which puts the burdon of most chores onto the Chart control from DataVisualization.Charting.
You can create EllipseAnnotations and add them to a Chart control.
Disable the Axes and clear the Legends and then use code like this to add a moveable circle wit thext inside:
EllipseAnnotation ea = new EllipseAnnotation();
ea.X = 11; // put at..
ea.Y = 11; // 11% of the chart's area
ea.AllowMoving = true;
ea.BackColor = Color.BlanchedAlmond;
ea.Text = (chart1.Annotations.Count + 1) + "";
chart1.Annotations.Add(ea);
Note that there are quite a few annotation types available. which allow you to add Rectangles, Images, Polygons, Lines and pure Text.
And another pro is that saving or loading the graphics takes only one line each, as you can serialize a Chart out of the box!
:-)

GraphX for .NET is an advanced open-source graph layout and visualization library that supports different layout algorithms and provides many means for visual customizations It is capable of rendering large amount of vertices
https://github.com/panthernet/GraphX

To draw shapes follow here.Also you need a complete tut,you can follow here
Some insight is here:
To draw a simple shape at design time Drag the OvalShape or
RectangleShape control from the Visual Basic PowerPacks tab (to
install, see Visual Basic Power Packs Controls)in the Toolbox to a
form or container control.
Drag the sizing and move handles to size and position the shape. You
can also size and position the shape by changing the Size and Position
properties in the Properties window To create a rectangle with rounded
corners, select the CornerRadius property in the Properties window
and set it to a value that is greater than 0. In the Properties
window, optionally set additional properties to change the appearance
of the shape. To draw a simple shape at run time On the Project
menu, click Add Reference. In the Add Reference dialog box, select
Microsoft.VisualBasic.PowerPacks.VS, and then click OK. In the Code
Editor, add an Imports or using statement at the top of the module:
using Microsoft.VisualBasic.PowerPacks; Add the following code in an Event procedure:
ShapeContainer canvas = new ShapeContainer();
// To draw an oval, substitute
// OvalShape for RectangleShape.
RectangleShape theShape = new RectangleShape();
// Set the form as the parent of the ShapeContainer.
canvas.Parent = this;
// Set the ShapeContainer as the parent of the Shape.
theShape.Parent = canvas;
// Set the size of the shape.
theShape.Size = new System.Drawing.Size(200, 300);
// Set the location of the shape.
theShape.Location = new System.Drawing.Point(100, 100);
// To draw a rounded rectangle, add the following code:
theShape.CornerRadius = 12;
Customizing Shapes When you use the default settings, the OvalShape and RectangleShape controls are
displayed with a solid black border that is one pixel wide and a
transparent background. You can change the width, style, and color of
the border by setting properties. Additional properties enable you to
change the background of a shape to a solid color, a pattern, a
gradient fill, or an image. Before you change the background of a
shape, you should know how several of the properties interact. The
BackColor property setting has no effect unless the BackStyle property
is set to Opaque. If the FillStyle property is set to Solid, the
FillColor overrides the BackColor. If the FillStyle property is set to
a pattern value such as Horizontal or Vertical, the pattern will be
displayed in the FillColor. The background will be displayed in the
BackColor, provided that the BackStyle property is set to Opaque. In
order to display a gradient fill, the FillStyle property must be set
to Solid and the FillGradientStyle property must be set to a value
other than None. Setting the BackgroundImage property to an image
overrides all other background settings.
This SO link I found is also nice here

Transparent GeometryModel3D

I need to create a transparent GeometryModel3D.
Like this:
I tried this code:
var m = new Model3DGroup();
var panelsGeometry = MyMeshGeometry3D;
Brush br = new SolidColorBrush(Colors.Red);
br.Opacity = 0.5;
m.Children.Add(new GeometryModel3D(panelsGeometry, new DiffuseMaterial(br)) { BackMaterial= new DiffuseMaterial(br) });
But as a result I get this:
What am I doing wrong? Thanks.

You could use a transparent image with an ImageBrush, one pixel would be enough but you will need to set TextureCoordinates on the mesh object.

You need to use TextureCoordinates and you wil have to order the sides to be drawn from back to front so they blend correctly. WPF doesn´t do this.
See this article

Make sure your box mesh geometry contains 24 points. If your box contains the minimum number of points (8), then the behind faces won't be rendered.
For example, see here.
You can download the Normals3D.zip and change the brush opacity of the full mesh boxes to get the desired effect.

Changing stroke color dynamically

I am using stylus input to draw lines in a canvas. I want to change the color of the stroke with the pen pressure. so I used:
DrawingAttributes dattribute = new DrawingAttributes();
inkcan.EditingMode = InkCanvasEditingMode.Ink;
if (stylusInput.pressureFactor < 0.5)
dattribute.Color = Colors.Red;
else
dattribute.Color = Colors.Blue;
inkcan.DefaultDrawingAttributes = dattribute;
but I have found that the color changes only when I lift off and retouch the pen to tablet surface. I am not sure how to fix that problem.
Any help would be greatly appreciated.

Look at this question: InkCanvas Eraser
In the MSDN it states:
If you change the EraserShape, the cursor rendered on the InkCanvas is
not updated until the next EditingMode change.
The effect you are experiencing might be caused by the EditingMode being changed when you pull the pen off the canvas and put it back down.
If so, you could toggle the EditingMode property as I suggested in the linked answer.
EDIT
Have a look at this a 3rd down it says:
Off course, life is never as simple as that, so there is one more
little issue to handle. Apparently, the InkCanvas uses different
renderers for the final result compared to while the strokes are being
drawn. To show a transparency based on the pressure while the
drawing action is still in progress, we need to use the protected
property called DyamicRenderer which gets/sets the object used to
render the strokes on a drawing context while the stroke is being
drawn. This rendering object must be a descendent of DynamicRenderer.
All you need to do here is override the OnDraw method and change the
brush that is used. When you assign a new value to this property, the
InkCanvas actually changes an internal 'PlugIn list' which is called
whenever data is entered using the stylus.
This might be it.

The if condition is evaluated only once, so there is no reason for the colour to change while you are drawing. Unfortunately, there seems to be no "onpressurechanged" event, so you would probably have to set up a loop that checks the pressure every x milliseconds and adjusts the colour accordingly.
Since you don't want to freeze the UI, you would either need to run it in another thread and delegate the colour change back to the UI thread, or you can queue the pressure checks onto the window dispatcher with "applicationIdle" priority. This would look something like:
void checkPressure(InkCanvas inkcan)
{
//return if touch is lifted code here
DrawingAttributes dattribute = new DrawingAttributes();
if (stylusInput.pressureFactor < 0.5)
dattribute.Color = Colors.Red;
else
dattribute.Color = Colors.Blue;
inkcan.DefaultDrawingAttributes = dattribute;
this.Dispatcher.BeginInvoke(new MyPressureDelegate(checkPressure), DispatcherPriority.ApplicationIdle, inkcan);
}
assuming your stylusInput shares scope with the function, of course. Otherwise you'd need to pass it in along with the canvas in an object array.

Default 3D chart transparency with ASP.NET Chart Control?

like two guys before me there and second one there I have difficulty with 3D chart.
How to force them to be transparent like this picture:
taken from 3D Area chart example shipped with ASP.NET Chart controls. This chart has ChartColorPalette.BrightPastel pallete, but is transparent.
I have also 3D chart with ChartColorPalette.BrightPastel palette, but is not transparent and I still cannot found way how to make it transparent like example chart. (After examining example markup and codebehind):
The only way I've found is to set the color of series with alpha channel for transparency, or use color palette with transparent colors (for example ChartColorPalette.SemiTransparent) but there must be some other default way which I'm missing.
Reason I really need this to know is that I'm creating graphs without any code behind just using markup, so I'm finding it a little bit redundant to create code snippets only because of this.
Thank you very much for any answers.
Edit: I'm using .NET 3.5 version of ASP.NET charts.

I'd same problem here. Solved using this:
// After all series manipulation, add this
chart.ApplyPaletteColors();
foreach (var serie in chart.Series)
serie.Color = Color.FromArgb(220, serie.Color);

I see you're on this thread too. Unfortunately, you do need to use colors with an alpha channel in order to set transparency AFAIK
Here's a good overview of the palettes available and some basics on manipulating them
My guess is that you could create a new palette by iterating over the colors in the bright pastel palette and adding an alpha channel - if you do this in a global static, perhaps as part of your webapp init logic, you should be able to reference it pretty easily - if you don't want to have any codebehind, you ?may? be able to databind your custom palette to the CustomPalette property, but I can't say with certainty.

If you do use palette, and not one color per series, you have to set color for every point:
myChart.ApplyPaletteColors();
foreach (var series in myChart.Series)
{
foreach (var point in series.Points)
{
point.Color = Color.FromArgb(220, point.Color);
}
}