I have a problem that all of my LinesVisual3D are not visible, when placed after an object with semi-transparent material (lowered alpha channel). All other 3D objects are visible when placed behind, but the lines are not. What is more, when the lines partially intersect with the object, only the part that is not intersecting is visible.
Is it possible to make these lines visible?
I believe this might be an effect of how WPF 3D handles opacity. I've had similar issues with other Visual3Ds.
Have a look at Transparency in WPF 3D.
Basically you have to add opaque and transparent objects in the correct order. Try adding the opaque objects last. I.e. add the LinesVisual3D you're having issues with, then add the things with lower opacity.
Disclamer: I have not tried your scenario with specifically LinesVisual3D, so it might be that there is a bug in Helix regarding that specific visual.
Related
I am trying to figure out how to add a full shadow around a borderless form, using WinForms. I am looking at adding a shadow around all four sides of the form.
I have tried using the DropShadow class, although it only adds the shadow to the bottom and right side corners.
I have seen this question asked many times before in my searches but nothing I cam upon had an answer for all four sides.
I am using both C# and VB.net languages in my solution so any help regarding either language would be a big help.
You are going to have to manually draw this. I have done something similar before with a splash screen, I think. You need to decide the offset of the shadow from the client area of the form and either create a container (easier layout wise) to host its constituent controls or redefine its client rectangle programmatically if you need dynamic shadow size, and then draw your border. If memory serves, you will get the best results using alpha blending + lineargradientbrush to fade the shadow transparency out to the edges.
I've to draw a graph on a canvas (bound by a scrollviewer). And there are about 200 or so nodes in memory.
To keep the things simple, I have derived the nodes from a usercontrol which can render itself.
But I've not created the lines between the nodes. I know from MSDN that,
On the surface, the Geometry class and the Shape class are quite similar. Both are used in the rendering of 2D graphics and both have similar concrete classes which derive from them, for example, EllipseGeometry and Ellipse. However, there are important differences between these two sets of classes. For one, the Geometry class lacks some of the functionality of the Shape class, such as the ability to draw itself.
Because there can be lot many more nodes, the system may render things slowly. Hence, to increase performance, I feel the best choice would be Geometry (custom rendering).
My questions:
Should I go with Shape or Geometry to draw the lines?
Should I render only the current viewport area of the scrollviewer to speed up the display (in which case I would have to convert the nodes from controls to geometry objects), or should I just iterate over ALL the nodes and draw lines between them?
Should I render the graph in memory on a bitmap and then flip it? It sounds more like game programming that general application programming! :D
Doesn't WPF automatically takes care of rendering what's in view and what not for better performance?
A few points to ponder...
From your topic I get that you dont want the ability of nodes to redraw themselves as that may make them slower. Instead, you want to decide when and which node to draw. Am I correct?
Well that looks ok to me, however Canvas is never virtualized. I recommend going through the codeplex website and download the WPFToolkit source code. Under DataVisualization namespace you have several charting controls (even ScatterredChart which is similar to yours where lines are not drawn between nodes) and their source code. Observe what they have done. How have they increased performance of their graph tools.
I also came across this artical of how to implement a Scrollable Virtualized Canvas. Probably that can help you to achieve fast rendering of nodes over canvas.
Personally...
1] Geometries are lightweight and I like them.
2] Visual HitTesting can help you understand if an item is under rendered region i.e. within the bounds of the scroll view. Otherwise make it hidden so that it doesn draw itself. "Hidden" and not "Collapsed" because hueristic for scrolling would work fine.
3] I remember my colleague using even the virtualizing stackpanel with horizontal orientation so that it renders nodes and the unit view i.e. the region specific to one point on X axis so that such repeating regions would automatially fit together to produce a monolithic graph.
Wonderful that impelemntation was!
All the best and keep us posted of your progress on this.
summarizing I have implemented a chart control as a simple Canvas with a Polyline on it. The next thing I need is to be able to zoom the chart.
I would like to know how would you that (just the idea, no details needed). What I would like to do is to create somehow a bigger Canvas and paint the line bigger and just show a part of the Canvas to the user, and the he drags the Chart it will move the Canvas. Something like in the following picture. Do you think this is possible?
Kael Rowan from Microsoft Research built a ZoomableCanvas class that may do exactly what you want. You can also see all the posts he wrote about it. You can even try a running XBAP example if your browser supports it.
We use the RenderTransform for this, create your zoom and pan matrix( or transform ) and apply that to your canvas. The nice thing is, that you can still have elements that can display behind or on top of the canvas with the identity transform or with another. For example for a grid or screen space elements like a minimap, which should always be visible. You might also want to look into this old question, which is somehow related.
my current free-time project, in order to dive into WPF MVVM, is a "digital" copy of an old puzzle I used to play a lot in my childhood. It basically is a simple puzzle where one has to fill a given space with different kind of pieces so the whole space is filled. But with the extra twist of being in hexagonal space.
Just to illustrate, this is what it currently looks like in WPF:
http://img190.imageshack.us/img190/2553/atomgridmolecule.png
So basically there is a number of predefined pieces(like the orange one above) which can be "plugged" into the given grid(the gray stuff above).
So the result might look something like this:
http://img30.imageshack.us/img30/2553/atomgridmolecule.png
I want the user(probably only me^^) to be able to drag and drop the pieces into the grid. I want the dragging to look natural meaning having the correct offset while dragging depending on where the user clicked the piece.
Both grid and molecule are the same control, a custom hexagonal panel control derived from the WPF Panel class.
The problem is on how to do the "plugging in" and especially the "unplugging".
I have two ideas on how I might tackle this:
Just color the cells in the grid and hiding the original piece
Pro:
Zero cost perfect alignment of the cells
Cons:
Recreating the piece at the right spot with the correct mouse offset if dragging out, seems impossibly? hard to do
Snapping the piece to the grid and show it on top
Pro:
Dragging out is a simple dragging operation, just as dragging in
Disadvantage:
Somehow have to align the piece with the underlying grid, some kind of snapping
So which approach should I take? Even more important how can I even implement this in WPF? Especially using a clean MVVM way.
Thanks so much for your help! Any input is highly appreciated!
EDIT:
Thanks Aran, I thought so too.
But how do I actually implement this now?
How can I actually get the coordinates?
All the orange circles are linked, so how can I "move" or better "plug" them in as one piece?
Im inclined to go with the second idea. a simple snapping would just be to test if the centre point of the circle you are dragging is within some tolerance factor of a circle on the grid and if so snap them.
I can draw a 3D border using ControlPaint.DrawBorder3D, but I get the 'Windows Classic' 3D border. I want to draw the current theme's 3D border - in the default XP theme, this is a 1px blue or gray border. How do I draw that, and how do I get its widths?
Sounds like you might need to look at System.Windows.Forms.VisualStyles.VisualStyleRenderer:
The System.Windows.Forms.VisualStyles
namespace exposes VisualStyleElement
objects that represent all of the
controls and user interface (UI)
elements that are supported by visual
styles. To draw or get information
about a particular element, you must
set a VisualStyleRenderer to the
element you are interested in.
To draw an element, use the
DrawBackground method. The
VisualStyleRenderer class also
includes methods, such as GetColor and
GetEnumValue, that provide information
about how an element is defined by the
current visual style.
There's a code sample on that page as well.
You will have to draw the border yourself, but you can get the color from VisualStyleElement.Window.Caption.Active and the size should be the size of the window frame (I believe), which is VisualStyleElement.Window.FrameBottom.Active. If you explore the VisualStyleElement.Window, you should be able to determine which window element has the information you need to draw your border.
Pre .NET Framework 2.0 Answer
I'm assuming that you are drawing your own, special control and you want to use elements of the currently active theme to draw it so it better fits with standard XP controls. You're NOT trying to, for example, enable theming on a standard Button control. Correct?
It's actually somewhat complicated. Your main focus should be UxTheme.dll. This houses everything you need for drawing themed controls. Here is a nice C# wrapper around this dll to make your life easier. There are others so if this isn't exactly what you wanted, I hope I've pointed you in the right direction.