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How to create a masking effect in unity

how would I create an effect like the one in the link in unity with c#? i would like to control the reveal of a 3d object with a slider. is it possible? some kind of mask i assume?
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If you want to do this specifically with c#, you will need to use the Mesh api to generate a sphere mesh, then modify the verts to remove the ones you don't want to display. A much easier solution would be to use a fragment shader to not draw the pixels that were outside the boundaries you define. This would be much more versatile as well, it would apply to any mesh you provided to it.
Discarding pixels based on world position shows how to get a similar effect.

Detect mouseover of non-square part of an Image

So I am working on a Risk type game in XNA/C#. I have a map, similar this one, and I need to be able to detect mouseovers on each territory (number). If these areas were squares, it would be easy, as they could each be represented by a rectangle. However, they are different size polygons. Is there a polygon shape that behaves similar to a square? If there isn't, how would I go about doing this?

I sugest this:attach color to each number, recreate your picture in these colors: every shape will be in its particular color. Dont draw it onscreen, use it only as reference map. And when the user clicks or moves mouse over your original map, you just simply project mouse coordinates into the color map, check the color of pixel laying under the mouse and because you have each color associated to number of territory...

This is not c# specific (as I've never written anything in the language, so no idea of what apis there are), though there are 2 algorithms that come to mind for detecting if a point is inside a polygon (which can be used to detect if a mouse point is over another polygon/map shape).
One is based on raycasting, where you cast a ray in 1 direction from the (mouse) point to "infinity" (edge of the board in this case) and count the number of times it crosses the polygon's edges. If it is odd, then the point is inside the polygon, if it is even, then the point is outside of the polygon.
A wiki link to it: http://en.wikipedia.org/wiki/Point_in_polygon#Ray_casting_algorithm
The other algorithm that comes to mind works only for triangles I think but it can be more simple to implement I think (taking a quick glance at your shapes, I think they can easily be broken down into triangles and some are already triangles). It is to do with checking if the point is on the same (internal) "side" of all the edges in the triangle. To find out what "side" a point is on vs an edge, you'd take create 2 vectors, the first vector would be the edge itself (made up of 2 points) and the other vector would be the first point of that edge to the input point, then calculate the cross product of those 2 vectors. The result will be negative or positive, which can be used to determine the "direction".
A link to it: http://www.blackpawn.com/texts/pointinpoly/default.html
(On that page is another algorithm that can also work for triangles)

Hit testing on a polygon is not so difficult to do in real time. You could use a KD-Tree for optimisation if the map is huge. Otherwise find a simple Contains method for a polygon and use that. I have one on another computer. Let me know if you'd like it.

Fill clipped area with color

I'd like to achieve an effect in XNA where I move a clipping plane through an object, and the object gradually disappears WHILE the clipped area is filled with a custom color or texture.
This is what I was able to achieve via HLSL:
And this is what I would actually need:
I think the teapot isn't a really great example because the models I would use would always be fully closed at all times.
Are there any good solutions to this?

I think that if you just have calculated if a pixel is front or back, you don´t need to clip it if the pixel is front, you only should set the pixel normal to the plane normal value, and calculate light as usual...

resolution independent grid for animations?

I'm working on a game made in XNA,C# and I want to enable xml based animations.
XML will look like this
<Animation>
<AnimatedObject>
<Filename>Spaceship_Jet_01</Filename>
<Flipped>false</Flipped>
<StartPosition_X>300</StartPosition_X>
<StartPosition_Y>500</StartPosition_Y>
<GOTOPosition_X>650</GOTOPosition_X>
<GOTOPosition_Y>500</GOTOPosition_Y>
<Time>10000</Time>
</AnimatedObject>
</Animation>
This will move an object to the side, like this
http://imm.io/odc7 (sorry the X coordinate is wrong)
I noticed there will be problems, when the players display resolution is different from mine because I enter pixel precise information about where the object comes from and where it has to go.
I thought about a grid so I can tell the programm to move the object from (30,27) to (22,27) e.g.. Is this a good solution? The grid has to be independent from the resolution but the number of tiles has to be constant and I have to draw the object to the screen. That means I have to find the right pixle position of the tile at position (22,27) and then "move" the object to that tile.
Is there a better way to do that? How can I solve this with XNA?

If you use a 2D camera you won't have any problem... because calculating the new view to adapt it to the new resolution is not difficult.... and you have not to change anything of your loads methods nor logic...
You can do, but I don`t like
Work with positions in [0..1] range, is difficult to measure.
Fix the position with the new resolution factor when you load the xml... is ugly...
Pos *= NewResolutionSize/DefaultResolutionSize;

Remove Kinect depth shadow

I've recently started hacking on my Kinect and I want to remove the depth shadow. The shadow is caused by the IR emitter being positioned slightly to the side of the camera, so any close object will get a big shadow and distant object less or no shadow.
The shadow length is related to the distance between the closest and the farthest spot on each side of the shadow.
My goal is to be able to map the color image correctly onto the depth. This doesn't work without processing the shadow as this picture shows:

Does the depth shadow always come out black?
If so you could use a simple method like a temporal median to calculate the background of the image (more info here: http://www.roborealm.com/help/Temporal_Median.php) and then whenever a pixel is black, set it to the background value at that pixel location.

I did some preliminary work on this problem a few weeks ago. My code works directly on a WriteableBitmap rather than the depth data, but if you're only doing image processing, it should work. The algorithm isn't perfect and would benefit with some more tweaking. If you update the code at all, let me know; I'd be very interested to see what you're doing!
The source code is posted on my blog:
http://richardpianka.com/2011/02/trackingni-depth-correction/

I don't know how it is with c# but openni c++ has a function called xnSetViewPoint() the only problem is, you lose the top 20 or so rows of imagedata due to the transformation.
the reason is due to using two different sensors, which are placed close by each other but not exactly at the same position.

Kinect Method - MapDepthFrametoColorFrame
Get the [x,y] positions in the depth frame, and use that method to fill in

I'm sorry to say but that shadow is caused by your body blocking the inferred dots from hitting that spot of the room so it creates a black spot... Nothing you can do but change the base background to a different color other than black so it won't be a noticeable shadow

The color camera and kinect depth camera dont have the same dimensions, and origin of the infra red dots are not from the same cam, its a IR projector a few cm aside from it (as that displacement is used to calculate depth).
However the solution seams easy here, your shadow data is on the left side.
so you need to extend the last known color data before it went black.
And to fit it better move translate the color cam data to the right.