[redsniper]

[19:31] <redsniper> I want to take some screenshots (eventually a video) of some ships fighitng
[19:32] <redsniper> then somehow edit the frames, so the background is transparent
[19:32] <redsniper> then make an animated texture out of that
[19:33] <redsniper> I've tried 'recording' this with a solid color background effect, then changing that color to alpha in GIMP
[19:33] <redsniper> but it changes the colors of ships and beams and things too; I don't know enough about green-screening to make this work...

So like, just now I was trying this with a magenta background. But when I do the color-to-alpha, the ships end up tinted green, and the beams lose their color.

Any ideas from the more experienced image editors here?

[Nighteyes]

A few suggestions:
if you'r only adjusting single images, take a screenshot with a purple(or any other color then black, so there is a good contrast with the ships), and in photoshop use the magic wand tool, select the BG and delete.
if you want to edit a video, I'm not sure how gimp works but I'm sure its not that different from after effects, just search youtube for many simple and easy tutorials

[redsniper]

[19:34] <Flaming_Sword> use gimp
[19:34] <Flaming_Sword> select by colour
[19:34] <redsniper> nope
[19:34] <Flaming_Sword> make the fuzz zero
[19:34] <redsniper> nope
[19:34] <Flaming_Sword> so you only have that colour
[19:34] <redsniper> alpha blended effects, bro
[19:34] <Flaming_Sword> then hit delete
[19:35] <Flaming_Sword> blending, eh?
[19:35] <redsniper> like the edge of a beam
[19:35] <Flaming_Sword> bit different then
[19:35] <redsniper> will be partially the background color

[Droid803]

Why don't you set color as transparent, then use hue/saturation (or color balance) to fix the colors?

[Aardwolf]

GIMP:

There's a color select tool. Set the threshold to zero, and it'll select ONLY the exact color you click on. Add an alpha channel to the layer if it hasn't got one, then press delete.

Edit: nevermind. That won't work. He wants beams/explosions/engines to be semi-transparent.

[FreeSpaceFreak]

Semi-transparency? It's near impossible to get that right, and you'll have to do each element separately. I know, I tried. If you really want that, you can try to recolour the ships back to their original colours (hard to do though).

I usually take view angles from where the engines aren't visible, for convenience. Then I do select colour, expand the selection by 1px , feather it by 2px, and delete. It gives adequate results, good enough when scaled down some.

But if you really want to get high-quality images on a transparent background, in true colours, and with semi-transparency, I suggest you learn to render. It will take you quite a while, but it does what you want.

[ShadowGorrath]

Select by colour, color to alpha while that color is selected. Alpha blending should be preserved.

At least that worked for me...

[Aardwolf]

There is no alpha blending to preserve, because he's going from in-game shots.

Sheesh.

[Colonol Dekker]

TOLWYN!!!!!!


Can ytou refer him to the guys who made that EPIC WIN wing commander movie?

You know the one...
Also, where did they get the Conferation uniforms?

[IronBeer]

You in the right forum, Dekker?

[Getter Robo G]

Yes he is, it is almost exactly what Redsniper asked about.

If you have ever seen the material, it would  have been self evident that Dekker's post was constructive..

Nuff said.


Also, before my Catastrophic (and final) HD crash, I too had been preparing for a little green screen exploration.

Now all projects are 99.9% lost and the modding clock has been reset to 7+ years ago. 12 if you count the actual beginning, which was just the resource gathering part, long before I knew I could mod things myself...

Real Life is a harsh mistress and demands you learn from her at times.

[gevatter Lars]

TOLWYN!!!!!!

Can you refer him to the guys who made that EPIC WIN wing commander movie?

You know the one...
Also, where did they get the Conferation uniforms?

I thought I mentioned in the credits who made the uniforms?
Anyway they are made by my mother. *Thanks mom* ^_^

I still have them and frankly, close up they don't look like much. Allways thought that I should get them into a better shape, put a "Wing Commander Saga Developer" logo on the back and wear it in public.
Bet I would create a new trend ^_^

Anyway, back to topic.
I never had the problem with my movie as its completly CGI created. So everything that should have an alpha had one from the beginning.

Still there are ways to get the background or lets better say a specific color out of a video material.
The magic word here is keying.

Be warned that, depending on the video material you have and the software you use, the result might not be that good.
As it was allready mentioned you need a pretty good contrast or a different color for the background to the stuff you want to remain.
For high contrast you can use a lumination key and for a different color you are using a color keyer.

From what I understand you have recorded a FS2 mission and now want to key out the background?
I would go back and edit the mission. Change the skybox to a complete green, purple, whatever color that is NOT on the objects you want to key.
Also make sure to deactivatet the envo mapping as this might result in fighters haveing a slight color tint from the skybox. That would result in semitransparant fighters.
Without knowing the material its pretty hard to say how to approach this at best.

When you want to edit still images, that is a lot easier but you could use the same methodes as with video material or you do it by hand. In most cases I do a mix of automatic tools and handwork.
Oh if you can allways use a non-destructive working methode. That way you can allways go back or later on change stuff you don't like.
I don't work with Gimp but in Photoshop there is a possibility to use layer masks. These allow you do key out stuff without realy deleting these parts.
Basicly you paint an alphamap right on the image with your paint tool. Its a very powerfull way to edit images as you can also use that mask as a real alpha-channel map later on.

Well I think that is, without knowing what you want to do in detail, as far as I can help you.

[chief1983]

Create a lime green skybox model?

[redsniper]

First of all, this is all for the purpose of simulating HUGE battles. The idea is to have an animated texture either as a background image or mapped to a simple plane model far away to show distant parts of the battle without having to put too many actual ships in a mission. I'm also considering using the draw.model scripting function (or whatever it's called) for closer ships. This is all just experimental, proof-of-concept stuff right now, trying to see what's feasible.

I've tried pure green, black, and magenta backdrops. The problem is finding a color that's significantly different from the ship and effects colors. Using green messes up green beams, magenta messes up red on Shivan ships, black works okay for the effects but makes the ships all semi-transparent because they tend to be dark. This will probably end up requiring more careful selection of ships and beams so that they have similar colors. It would be ideal if I could just have some way to make a 'transparent' background or something.

I've also considered doing this all in Blender, but then I'd have to do ship movement and beam firing and explosions all by hand...

[gevatter Lars]

Blue isn't also working because of some blue beam I guess. What about a bright yellow? Anything yellow in the scene?
I guess FS is useing every color of the rainbow so you will end up with one color to have an issue or the other. Question is what is the least problematic one?
For example with the beams. Is that something you might be able to add later on via post pro?

[JGZinv]

Pure white or orange?

[chief1983]

You could use different backdrops for different parts of the shot depending on what's on screen at the time.

You might even be able to change the skybox via SEXPs so you could possibly do it all in one run.  You wouldn't be able to have all the colors on the screen at one time of course but you could still get them in at various times during the mission.  Then just break the video into its segments and apply the removal of the right color to the right segments.

[redsniper]

I found a kind of hackish solution. Since the semi-transparent effects were causing so many headaches, I tried making an opaque beam effect. I took a screenshot over a black background, did color-to-alpha, then selected the parts of the image that aren't fully transparent and did a black bucket-fill. This made the background transparent, while leaving the ships looking just fine. Obviously, the effects won't look as good using this method, but for the kind of ranges in question, a beam will only be a few pixels wide, so I think it's okay.