Best way to create clickable real world map?

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Hi, Is there a sample or best practice in creating a clickable real world map? Where you can scroll and select countries or even different parts of the countries.

Here is a screenshot of "HOI III" game from Paradox.

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Answer 1

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Answer by Dragonlance · Aug 13, 2012 at 05:35 PM

Yes!

Use a rectangle with(!!) UV mapping on it. (This will be your map)
Use it normal with your diffuse shader or whatever you like to represent it.
Give it a mesh collider!
Have an aspect ratio fitting texture with color encoded shapes (so i.e. 0x00FB0022 would be Berlin area color) - This texture will not be applied anywhere, it is just for looking up the color (and with it the area).
Do a raycast from screen like http://docs.unity3d.com/Documentation/ScriptReference/RaycastHit-textureCoord.html
Use the UV coordinate to look up the color on your reference texture (the one that was not aplied anywhere).
Look up the found color in your Color<->Area Map
...
Profit?

You know what area the player clicked.

This method can be used with basically any other shape. You only need to have a color encoded lookup texture fitting to the uv coordinates on the object. You could use this for decals, target zone testing etc. But it has to be a mesh collider, what could be a performance problem for very complex objects. But in this case you will be fine.

The bigger problem is to mark the areas as selected. For this you need to have a transparent (for nicer look) detail overlay texture for your map. Use your reference color texture and copy just that colors shape (defined by its color values) out of it, do 0 alpha on the other pixels, give the non alpha pics the color of your desire and copy it additive on the into the detail overlay texture.

Have fun!

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Muuskii · Aug 13, 2012 at 06:21 PM 0

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As the guy in Peggle said: "Cleverly done!"

dzed · Aug 13, 2012 at 07:32 PM 0

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Just to make sure that I have understood you right. What you are suggesting is to have a huge texture(image) of world where every country or region has a unique color? And then by using Texture2D.getPixel try to match the color with a color table, to find the selected region? And concerning the overlay/selection graphics basically do the same find the x,y pixels of the "selected" color and set the rest pixels to alpha=0.

Dragonlance · Aug 14, 2012 at 07:18 PM 0

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Yes that's pretty much it.

You use uv coords from the RaycastHit to look up on another texture with unique color for each area. This color can be used to a) find out what area was clicked b) extract the shape of the area to paint a selection in another texture.

You can not use Texture2D.getPixel(x,y) directly, because u,v coordinates are not x,y coordinates. Either you calculate u,v to x,y or you use GetPixelBilinear(u,v).

After that you can use GetPixels or GetPixels32 (Color32 is faster because of no need for float conversion) to get the pixels and from that the overlay shape.

There are a lot of things that could be optimized after you did implement the basics.

Speed: You can do that GetPixels32 one time at startup of the campaign map scene and leave it i memory. - Then you allways extract shapes from that Color32 array.
$$anonymous$$emory: You could have a map of bounding rects for u,v coords and just check the desired bounding rect for fine tuning (many will ovverleap so you could use GetPixels on a bounding rect)
$$anonymous$$ore optimizations you may think up yourself, or maybe somebody has other ideas?

Answer 2

Answer by sketchers1 · Aug 13, 2012 at 06:15 PM

OOH OOH! I did the same thing! So in addition to what dragonlace said or being part of it, this is what I had asked: http://answers.unity3d.com/questions/165131/gui-on-click.html

and It works perfectly!

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Answer 3

Answer by Loius · Aug 13, 2012 at 05:12 PM

I'd recommend OnMouseEnter / OnMouseExit.

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Best way to create clickable real world map?

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