Render OpenGL scene at two different locations - c#

I am writing an application that renders an OpenGL scene. This application has two windows:
A large window that shows only the rendered scene
A "control window" that offers several settings and a preview of the rendered scene
This application is written in .NET (for the control window part) and uses a native C++ DLL to create the rendering window and do the actual OpenGL rendering.
This works fine, but one important part is still missing: getting a live preview of the rendered scene into my .NET control window.
So far I could think of two solutions:
Render the scene not only to the screen, but also to memory. Then shove that blob of memory to my .NET WinForm. Finally draw the image to a PictureBox or something. <- This sounds horribly slow!
Make my native OpenGL renderer render the scene twice, once to the native full size window, once to a control (panel?) on my .NET form.
Option 2 sounds faster, but I have no idea if/how that even works.
Can this be done? Are there better alternatives?

Look into the documentation on framebuffers. It is basically the destination of your rendering, by default it's your viewport (or the backbuffer, which switches with the displayed buffer once it's ready).
The first option should generally be faster as you render the scene once and then just basically copy a texture.

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Render CefSharp Offscreen Control in WPF

I currently have the problem to display a OffScreen Control in a WPF context.
I could use the WPF control given by cefsharp, but the problem is that the control only gets initialized when drawable (which is a problem).
Rendering a image is no big deal, but want to display a series of images (no high framerates is needed), also should it not eat the whole performance on the computer while doing this.
Best regards,
Sebastian

XNA Graphics Device WinForm

I'm making a GUI editor for a game engine that only allows DDS image files. I've had no luck finding any WinForm way to load DDS files so I looked at the XNA route. I found a DDSLib that uses XNA to load DDS files to Texture2D types. Then I think I can save those in memory as bitmap and use them in my WinForm. However this requires a Graphics Device object. How can I get this Graphics Device object without having any sort of visual thing. Everything I see shows controls which makes sense if you want to show something, but in my case I just need it behind the scenes to do these conversions.
It may not be an elegant solution but you could just set the XNA frame within the winform to not be visible?
Edit:
Just found this: How to load .dds files into a picturebox?

Avoiding game loop in XNA 4.0

I developing a simple 3D model viewer on XNA 4.0. Is there a way to avoid a infinite game loop with Draw and Update functions? I need render 3D graphics, but without infinite rendering of scene. I mean I need redraw the scene only then it really changed.
I suggest taking a look at how they're doing it in their samples:
App Hub - WinForms Series 1
App Hub - WinForms Series 2
Why exactly do you want this?
If you use a winforms application you have more control on your update and draw loop, but you also could render the scene to a texture first, and then stop rendering at all.
You are going to have to roll your own multi-threaded loop; if you stall either Update or Draw the other will get stalled too. Another consideration is that if your window gets obscured somehow (under non-DWM environments; a window overlapping it for instance) stalling the Draw will leave areas of your window unpainted.
If you want to go ahead with this; what you will do is start a Thread the first time Update gets called and subsequently use a ManualResetEvent to synchronise the two.
A far more robust option is to render your entire scene to a RenderTarget2D when the scene is updated; if the scene has not been altered since the last Update or Draw call simply render the RenderTarget2D instead of the whole scene. This is still an infinite loop, but it tends toward your requirement (even though it does not meet it).
This sort of scenario would be best solved by using WinForms or WPF as the host for your rendering system. I have worked with such systems before and I found using SlimDX with WPF Interop was my preferred solution. Using this approach allows for the addition of nice UI features provided by WPF, overlain on a 3D model rendered to a surface.

How do I create simple animations using a WriteableBitmap?

Greetings, everyone.
I'm trying to learn some Silverlight basics, and have decided to write a simple Mandelbrot-set drawing application for that reason. In Silverlight, of course. ;)
The application is mostly done. I'm using a WriteableBitmap to work on the pixels, and a simple Image placed on an empty form to display this bitmap (using the Source property). I've even managed to get zooming and moving the fractal around under control.
Now I wanted to spice things up a little bit by adding just a slight bit of animations; I know I cannot make the fractal move, as it's a scalar graphics object, but for example, when I zoom in, it would be nice if the initial zoom was a smooth animation, after which the application would recalculate the new, "zoomed in and sharp as a knife" image. Likewise, if I drag the image around (which is used to move the fractal) and the mouse leaves the image area, it would be great if the fractal returned smoothly to it's initial position (as it is now, it just "snaps" back as the initial settings are restored).
My problem is that I have no idea which parameter to control in an animation. I'm using ScaleTransform, for example, for zooming, but that is used to render the WriteableBitmap on the bitmap itself rather than use the transform properties of the image object. I did so because when I started manipulating the image properties, then the whole image started to move around the form, when I'd rather it's boundaries stay in place.
I suspect I may be trying to do something which Silverlight wasn't really meant to do in the first place (or I've started doing this whole thing wrong), but if I COULD add such little animations, that would be great. As such, any tips appreciated.
It sounds like you want to use the Silverlight animation engine to animate your own custom properties, that control your image display, rather than the image elements or containers.
If your properties for controlling the appearance of the image were exposed as double Dependancy Properties, then the animation system can use the basic DoubleAnimation objects to change your settings smoothly over time. You can even author animations in Expression Blend.
The animation engine would certainly give you easing functions etc to smooth out motion. If I had more detail on how your object was structured I could be more specific, but I hope this helps.

Spinning a 3D model in C#

How do I take a 3D model that I created in 3D Studio Max and put it into my Winform C# program and make it spin? I'd prefer not to use DirectX if possible. I don't want anything complex. I simply want my model to rotate along the X axis. Thats it.
Thanks
You should use a 3D rendering engine for C#
Something like
http://axiom3d.net/wiki/index.php/Main_Page
http://www.codeproject.com/KB/GDI-plus/exoengine.aspx
http://irrlicht.sourceforge.net/features.html
http://freegamedev.net/wiki/Free,_cross-platform,_real-time_3D_engines
I have never used any rendering engines but for your requirements (letting the user move the object) i think a 3D engine would do. But perhaps this is over kill
If you want it to be dynamic, then the simplest option would be to render out an animation of the object rotating, but make each frame a separate file. Then you just show the correct image based on how the user is dragging the mouse. If the user drags the mouse to the right, then increment the frame and show the next image. If moving to the left, decrement the frame.
For something non interactive:
Export the animation to an AVI and embed that in your form:
Embedding Video in a WinForms app
It's not really what I'd recommend, but it's an alternative to creating an animated gif.
For something partially interactive (i.e. allowing limited movement):
I've seen QuickTime movies that you can control with the mouse. There's an example on this page. It's not 3D though.
For something fully interactive:
You need a 3D rendering engine of some sort and that does (usually) require DirectX or OpenGL. However, if you're only dealing with simple objects you might (repeat might) get away with a software renderer.

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