Tutorial - Using a green screen map.

[m4gnificent_b4st4rd]

I've made a simple greenscreen map, see this thread. This map is empty apart from alien and human spawn, with everything else being a flat, shadowless map.

Here's a quick demo of what I did with it.

- I opened up the console and set cg_shadows to 0.
- I then spawned as a human in the game, committed suicide, respawned and took a screenshot of the body.
- I loaded the screenshot into gimp, cropped it to size and chose the Select > Select by colour tool.



- With all the green selected I removed it with the eraser tool.



- I then clicked Select > None to remove the selection.
- I used the eraser tool some more to remove the crosshair and gun.
- I saved the image as a PNG (to keep the alpha layer) and then overlaid it on another image.



- Resulting in my final image of a shipwrecked marine.

This was just a quick and dirty tutorial, but you get the general idea. 

[Taiyo.uk]

Now antialias those jaggies and scale him down so he doesn't appear to be 20' tall. Add some mutilations else people will assume he just drank too much.

[m4gnificent_b4st4rd]

Taiyo.uk - Yeah, it is a bit rough, wasn't done as a serious attempt though.

Interestingly enough it actually looks better without anti-aliasing on because there is a clean distinction between the model and the background which Gimp can easily separate. With anti-aliasing you get pixels which are a mix of the model's colour and the background colour so the colour select tool doesn't work cleanly and you are left with a greenish edge around your model.

Not sure what the solution to this is to be honest. It's possible there is a filter that could soften the edges slightly to give a pseudo-anti aliased effect. Maybe someone with more Gimp knowledge than myself might have some suggestions.