Develop Reference

How to implement rigid body dynamics previewed by WPF 3D

I'm currently facing a problem with WPF 3D using C#. To put it simple, I need to animate some simple mechanical part by only moving two of them (one at a time or both together). Here is a simple drawing depicting the situation :
So by moving (translating) vertically P1 or/and P2 parts, the whole thing needs to move accordingly.
I guess it may be possible to do by computing a lot of angles and applying numerous transformations but this is not my goal.
Therefore I would imagine something like attaching the parts together by the means of a pivot point.
What is the preferred way to do this to preview it using WPF 3D?

WPF 3D, Ogre, Mogre, OpenTK... are libraries for display. They have nothing to do with mechanical constraints calculations. But they goes well with physics engines.
WPF 3D is a subset of WPF dedicated to 3D drawing. If you need 2D, then WPF is enough.
As your project looks 2D, you might want to have a look to Farseer Physics which is a port of Box 2D. The feature you need is called joints. Both libraries target 2D games development, but they can be used for simple kinematics animations, and Farseer Physics is doing very well with WPF.

It's a simple problem for any 2D kinematics package.
http://books.google.com/books?id=IGtIWmM2GWIC&pg=PR12&lpg=PR12&dq=c%23+kinematics&source=bl&ots=eCJZLq_i6R&sig=wC42cNOdtw4VX9ElTk4IBDAYtzc&hl=en&sa=X&ei=3YkXU4u1EeHu2wXum4GYDA&ved=0CFsQ6AEwBQ#v=onepage&q=c%23%20kinematics&f=false

Web Page - 3d earthquake visualization - Silverlight?

I have never written any silverlight apps but I am looking to write a 3d viewer for earthquakes and have it run from my web site.
I would like to create a simple viewer so the user can change the "camera" ie their perspective. The view could contain up to 10,000 objects in the 3d space.
I want the ability to quickly view this - I have seen this on a Power Basic application and want to do this for the web.
I have a current web site at http://canterburyquakelive.co.nz for earthquakes in Canterbury New Zeaalnd and I want to learn the basics so that it can be more interactive.
I want to say for example (to start) place 2 objects in a "space" that I can define and move the camera in real time.
The system must support up to 10,000 objects in the end of the day.
Each object can be a simple circle - no need for special pixel shaders
I am unsure of the exact functionallity of the system at the moment so if I can find a tutorial that allows me to place someone (a circle) into a 3d world (space) and change the camera that would be good.
Any ideas appreciated - there seems to be so much about 3d and silverlight that I may be getting lost in the "gloss" of new features where I need some basics and I can learn and adapt over time.
** Added comment + image **
Basically I am waiting to create a page that look like this using Silverlight. But I am open to any technology.

I've never done 3D in silverlight so I can't exactly answer your question as asked but in general to display geographic markers in a 'real' 3D terrain is quite involved. At a minimum you're probably looking at:
Obtaining binary height data files (last time I looked, NASA gives this away)
Reading and interpreting said files to get 'bitmap' height data
Choosing and dealing with projections (e.g. UTM)
Deciding how to tesselate your bitmap height data
If you want it textured you'll need to also obtain satellite data for that, again converting or processing it to account for projection.
You could ignore the terrain height, but that may not simplify things depending on how 'bumpy' your terrain is.
For a pre-defined small enough area, you could perhaps pre-author a 3d model of the terrain in some 3D package but displaying your markers will still require a projection from long/lat into your 3D space, and you'll still need to know terrain height (unless you do mesh collision with the static model).
Rendering the markers is pretty straightforward by comparison, choose from:
Use a 3D model e.g. a 'pin head' (simple but not always visible)
Render a regular n-gon with 'viewer facing' polygons (resolution independent but maybe ugly)
Render a quad with a circle texture on it (low poly but what size texture to choose?)
There are probably libraries that do some or all of this for you, so if you are set on rolling your own then some of the things I've mentioned could form the basis for your search.
However, given what you've described of your site and situation I suspect you'd be better off avoiding all that work by using a pre-existing solution. E.g. the Google Earth API.

You could consider 3D web plugins that -granted- take you away from Silverlight but that might speed up your development process. I'm thinking in particular of e.g. the Blender 3D web plugin. I can understand the need to write your own viewer, but think twice before you re-invent the wheel. Good luck!

How to show text on the screen using OpenGL and C#

Situation: Simple 3D game project - OpenGL + C#
I read that OpenGL functions doesn't support easily print the text on the screen.
Have anyone clue how to do it? I don't need any too much sophisticated solution.
I just need show for example FPS rate in one corner or show the number of picked up objects in anohter corner.
thx.

One good method for text rendering is to use a texture with the font characters and draw one quad for each character with the good texturing coordinates. This usually gives good results and is platform independant. However this is quite heavy to implement.

Use wgl functions of Opengl32.dll on windows to render text. Example here: http://www.pinvoke.net/default.aspx/opengl32.wglusefontoutlines#
The basic process is you have to build a display list of glyphs in advance (rending the Windows font into an OpenGL context), then you can draw characters on the OpenGL display surface using the characters as indices into the pre-rendered display list.
For a prepackaged managed solution, take a look at Mono's Tao library: http://www.mono-project.com/Tao

http://nehe.gamedev.net/tutorial/freetype_fonts_in_opengl/24001/ This should give you all you want. Its in C++ but I am guessing that should not be a problem. It basically elaborates on what neodelphi suggested.
Although you say you don't need to much complexity and require it for just the FPS, having
a nice font rendering system comes in extremely handy.
HTH

3D Graphing Package For C# Winforms?

I'm using ZedGraph for my 2D graphing needs, but for a project, I need something that does 3d graphing. What is the best package I can use for this? I'd like the Graph Panes to be as easy to manipulate as with ZedGraph.
Edit: By 3D, I mean I want to be able to specify an x,y,z to get a surface. Thanks!

Using the source code that can be found in the link posted just below as well as WPF you can create a pretty good 3d graph, it's nothing groundbreaking but it might suit your needs:
3D Bar Chart

In principle you can create a bitmap using MathGL and display it. MathGL is cross-platform GPL (LGPL for core) plotting library which can plot 2- and 3-ranged data. However, I'm not sure what you can use C++ classes from C#. But C-interface should work.

How to make a circle to move in C#?

I want to write a simple game like pacman in C# in order to learn
the new language.
However, I don't know how to make a circle move?
Which part of knowledge in C# is needed?

You should check out XNA Game Studio from Microsoft. It's a version of Visual Studio that's targetted especially for writing games. You use C# but get a lot of things for free - graphics, sound, timing...
Here's a tutorial for making a ball move in XNA.

The simplest way would be to move your circle a small bit with every tick of a timer control.

If you want to learn a new language stay away from all fuss and just look into the most essential parts.
Having knowledge about previous programming languages helps a lot, espesially if one of those are Java.
You don't need to look into XNA for this, all you really do need is to Start Visual Studio, create a new Windows Form, drag over an PictureBox and start playing with the KeyEvents.
Your game does not have to be awesome for you to learn the very basics of C# and .NET. And you certainly don't need to dig down in the deep jungle of XNA!
Once you have your form up and running with a PictureBox or two and you have conqured the Event-system, take a look at the other fundamental parts of .NET that makes your life easier. Properties, Generics, Data Sources and much much more.

Well, for a simple single player game like that, some of the most important things you need to know about are data structures and GDI.
Data structures are important because you need to store information such as what does a map look like? Where are the walls? Can you go from one end to the other? How does the map draw itself?
GDI is used in C# to draw. This uses the Graphics context. You'll find lots of examples online, and I'd suggest checking out BobPowell.Net GDI+ FAQ to avoid some of the common mistakes.

You probably want to look into XNA - http://creators.xna.com/
Simply download the studio, install, then run Visual Studio C# (mine is Express Edition).
So when you run, you create a new Windows Game Project and you've created your first game.
Good to read up some books and articles on XNA.
Book: Microsoft XNA Game Studio 2.0: Learn Programming Now! by Rob Miles.

if you mean how to move an object around in a circular movement, then you just need math knowledge:
int circlePosX = centerX + Math.Cos(degrees) * radius;
int circlePosY = centerY + Math.Sin(degrees) * radius;
radius is here how big you want the circle to be, and degrees is the position ion the circle the object is moving.

Here's an answer to a question about a radar-type game that demonstrates generally how to do this in C#/WinForms using GDI+ (with a sample and source code):
What would be the best way to simulate Radar in C#?