I am rendering a 3D contour surface from data. I get new data every few seconds from real time monitoring and need to redraw using the new data. All of the examples I can find only show how render the 3D contour surface from fixed data.
I can't find an example of explanation of how to (clear, delete, erase) the mesh or model and redraw with new data.
Can anyone point me to an example or explain how to redraw the 3D contour surface with the new data.
I have solved this issue with the help of several answered questions.
Removed all children of the Model3DGroup 'main_model_3D_group'.
for (int i = main_model_3D_group.Children.Count-1; i >= 0; i--)
{
if (main_model_3D_group.Children[i] is GeometryModel3D)
main_model_3D_group.Children.RemoveAt(i);
}
rebuild the GeometryModel3D objects
add the GeometryModel3D objects back to the children of the main_model_3D_group.
Second Issue encountered:
I used an ImageBrush to get a gradient colored surface material.
The ImageBrush.ImageSource locks the file so you can't save the same filename with new color data.
Solved this with the following function;
public ImageSource BitmapFromUri(Uri source)
{
bitmap.BeginInit();
bitmap.UriSource = source;
bitmap.CacheOption = BitmapCacheOption.OnLoad;
bitmap.EndInit();
return bitmap;
}
This function leaves Uri source (xxx.PNG file) unlocked, but the 2nd call doesn't reload the file (assume because it is cached). Solved this by using 2 filename (odd/even). So every other call used a different filename.
Related
as you can read from the title i want to be able to draw some images on the screen, move them in some direction and video capture the movement with a good fps rate.
I want to specify that i do not want to record the desktop nor some portion of it but the content of the actual window in which the images are moving(so the window can also be minimized). Also if possible i want to be able to set a custom size for my view where everything will happen.
Where i should start from?
I have already tried with WPF but as the UI is single threaded i am not able to take a screenshot of the view while something is moving on it.
What library you would suggest me?
Are there similar open-source projects i can learn from?
Any suggestion i welcomed!
Here's some code I recently wrote to do this, it cycles through a number of frames and renders a control (in this case, a Canvas) into PNGs:
private void Export(int frame)
{
// force the control to update after any changes you've just made
theCanvas.Dispatcher.Invoke(DispatcherPriority.Render, EmptyDelegate);
// render the control into a bitmap
RenderTargetBitmap bitmap = new RenderTargetBitmap(1920, 1080, 96, 96, PixelFormats.Pbgra32);
bitmap.Render(theCanvas);
// save the bitmap out as a PNG
using (var stream = File.Create($"Animation/Frame_{frame.ToString("D3")}.png"))
{
var encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
encoder.Save(stream);
}
}
You can then use ffmpeg to pack those PNGs into the movie file format of your choice.
I am trying to display image using BitmapImage for some time and it worked.I have changed the image and it stopped working.
For Bitmapimage I was using this code:
`ms.Seek(0, SeekOrigin.Begin); // ms is memory stream
BitmapImage b = new BitmapImage();
b.SetSource(ms);
image.ImageSource = b;`
I have ran into piece of code where it was checking if the length of the bytes[] ==14400
if(bytes.length == 14400)
{
var bmp = new WriteableBitmap(width, height);
Buffer.BlockCopy(buffer, 0, bmp.Pixels, 0, buffer.Length);
}
I want to know when to use WriteableBitmap and BitmapImage .
From iProgrammer:
Bitmaps are generally implemented as immutable objects. What this means is that once you create a bitmap you can't make any changes to it. You can manipulate bitmaps by creating new versions, which then immediately become immutable....
The WriteableBitmap, as its name suggests, isn't immutable and you can get at its individual pixels and manipulate them as much as you want. This is the ideal way to work when you need dynamic bitmaps.
iProgrammer - WriteableBitmap
From MSDN:
"Use the WriteableBitmap class to update and render a bitmap on a per-frame basis..." MSDN - WriteableBitmap Class
The Examples section of the MSDN article also shows how to update a WritableBitmap image when responding to mouse events. The code in the example erases pixels of the image by setting the pixel's ARGB values to 0 when the mouse's right button is down. The code also shows how to update individual pixels in the image where the mouse's left button is down. Essentially the code shows a rudimentary pixel image editor.
The point, however, is that you can't change image data when using regular bitmap - you have to use WritableBitmap instead. You can, however, render both if you wish.
I am writing a map control that can display a bench of geometries. For better performance, I draw all my geometries using DrawingVisuals which I then write into a RenderTargetBitmap as shown in the code below:
public class Map{
public ImageSource MapDrawingImage{get;set;}
private void RenderMap(){
MapDrawingImage= new RenderTargetBitmap(w, h, 96, 96, PixelFormats.Pbgra32);
foreach (Layer layer in map.Layers) {
System.Windows.Media.DrawingVisual layerDrawing = Render(layer, map);
MapDrawingImage.Render(layerDrawing);
}
}
}
In order to display the map, the main window has an Image control which Source is set to Map.MapDrawingImage image source. To automatically update the image, I use the following data binding:
RenderOptions.SetBitmapScalingMode(mapImage, BitmapScalingMode.LowQuality);
// Map image binding
Binding mapBinding = new Binding();
mapBinding.Source = map;
mapBinding.Path = new PropertyPath("MapDrawingImage");
mapImage.SetBinding(System.Windows.Controls.Image.SourceProperty, mapBinding);
This works very well when the map is static. However, in a dynamic mode where the map is updated at a rate of 5 to 10 times a second, the data binding seems to fall a bit short behind and the application slows down. I have searched for long days and I found out that:
RenderTargetBitmap does not use hardware acceleration thus causing some delays when rendering the map.
Data binding might also cause some delays refreshing the map image
Is there any better way to improve the map performance (RenderTargetBitmap replacement, data binding improvement) ?
Thanks in advance,
Databinding is updated in a seperate thread. So this will always be with a delay. Also it works with a queue, so when the databinding can't keep up the queue will grow bigger and bigger. The solution would be that you use an image which is static and change the image itself instead of replacing it with another image.
I am new to Silverlight. Just created my first application that shows deepzoom images.
Looking for some pointers how to display vector graphics in Silverligth. The graphics are all in 2D and is a series of lines (x1y1, x2y2), points (xy), basic shapes. The data is available in ASCII text files.
What is the way(s) to read the data from files and draw in SL? Do I need to convert / translate the vector objects into images (XAML) first? Where to start?
The ideal case is that all vector obects should be selectable either programmatically or by user actions.
Thanks,
Val
There is no direct drawing API to my knoweldge, but you can add the values seperately by adding various shapes to the visual tree.
The code you are looking for will likely involve the Path class and, in turn, PathFigure and PolyLineSegment (or possibly LineSegment).
Below is some code that draws a square:
PolyLineSegment segment = new PolyLineSegment();
segment.Points.Add(new Point(0, 50));
segment.Points.Add(new Point(50, 50));
segment.Points.Add(new Point(50, 0));
segment.Points.Add(new Point(0, 0));
PathFigure figure = new PathFigure()
{
StartPoint = new Point(0, 0)
};
figure.Segments.Add(segment);
PathGeometry geometry = new PathGeometry()
{
Figures.Add(pathFigure)
};
Path path = new Path()
{
Stroke = new SolidColorBrush(Colors.Black),
StrokeThickness = 2,
Data = pathGeometry
};
// To render, the Path needs to be added to the visual tree
LayoutRoot.Children.Add(path);
Edit If the data in the ASCII text files cannot change at runtime, it might be worth investigating writing a script that transforms the files into XAML so it can be compiled.
First of you have the issue of actually getting access to the files.
Getting the file content
If you have these files held somewhere serverside then you would use WebClient to fetch the file using DownloadStringAsync.
On the other hand if the user is to open a file locally then you need use the OpenFileDialog class to ask them to open the file and then use OpenText on the FileInfo object that OpenFileDialog provides to read the string data.
Parsing
Well its your format so you'll have to code that yourself.
__Generating UI elements_
You will not have to convert it to Xaml. Since you want these vector items to be individually selectable elements then you probably want to use the set of Shape types found in the System.Windows.Shapes namely, Elipse, Line, Path, Polygon, Polyline and Rectangle.
No doubt the format in question has someway to define the position of these elements relative to a fixed 0,0 point. Hence the best panel to use to display these is a Canvas.
You would read through each Vectored item, select create an instance of one of the appropriate shapes set its properties based on the data in the item. You would need to determine its correct location within a Canvas and use the Canvas.Left and Canvas.Top attached properties. The add the shape to the Children collection of the Canvas.
This is my first day with Silverlight. I’m trying to prototype an application which (among other functions) should be able to resize user supplied images. It should be able to handle and display several resized images at once. The most obviously approaches I've tried seem to "leak" memory in the sense that the original bitmaps are still being referenced in some way which causes Silverlight to allocate hundreds of megabytes of memory after a while. I just want to be able to load the images one by one, resize them and keep the small versions.
To be precise, I've tried the following:
Creating a list of System.Windows.Controls.Image's (and scaling them). I'm not surprised that this has not worked.
Creating a list of rectangles filled by image brushes. I'm not surprised either.
Rendering the bitmaps into System.Windows.Media.Imaging.WriteableBitmap. I expected this to perform well; I assumed that the bitmaps are really just drawn directly and not referenced in any way. However, the memory consumption indicated otherwise.
Here is a snippet of the relevant piece of code:
// create image source
Stream stream = file.OpenRead();
BitmapImage bmpImg = new BitmapImage();
bmpImg.SetSource(stream);
stream.Close();
// create temporary image from it
Image tmpImg = new Image();
tmpImg.Source = bmpImg;
// this is required by WriteableBitmap
tmpImg.Measure(new Size(100, 100));
tmpImg.Arrange(new Rect(0, 0, 100, 100));
// prepare scaling to 100x100
ScaleTransform scaleTrans = new ScaleTransform();
double scale = (double)100 / (double)Math.Max(bmpImg.PixelHeight, bmpImg.PixelWidth);
scaleTrans.CenterX = 0;
scaleTrans.CenterY = 0;
scaleTrans.ScaleX = scale;
scaleTrans.ScaleY = scale;
// render
WriteableBitmap writeableBitmap = new WriteableBitmap(100, 100);
writeableBitmap.Render(tmpImg, scaleTrans);
writeableBitmap.Invalidate();
// final image
Image img = new Image();
img.Source = writeableBitmap;
I hope I'm not missing anything silly, but it looks to OK to me and does the right thing (except the memory problem). Please also bear in mind that code quality is not supposed to be a production quality; it’s just a quick and dirty prototype.
I noticed that I’m not alone; I found questions related to image manipulation in Silverlight. I’m also aware of the fact that I could use some third party library, do processing on the server or write something even myself, but I’m surprised that Silverlight does not offer any basic image manipulation functions. It does not seem to be an uncommon requirement given where Silverlight positions itself.
Have you looked at the WriteableBitmapEx project? It's an open source project with a tonne of extension methods for the WriteableBitmap class. Here's how you resize:
BitmapImage image = new BitmapImage();
image.SetSource(dialog.File.OpenRead());
WriteableBitmap bitmap = new WriteableBitmap(image);
WriteableBitmap resizedBitmap = bitmap.Resize(500, 500, WriteableBitmapExtensions.Interpolation.Bilinear);
// For uploading
byte[] data = resizedBitmap.ToByteArray();
I don't know about the specifics here, but if you're leaking resources - you might look at which of your objects implements the IDisposable interface. I would guess that the Stream and Image classes implement this interface. And if they do - calling Dispose() on them (or wrapping their usage in a "Using" statement) will cause them to free their resources immediately rather than waiting for the garbage collector to kick in eventually.