Simviation Forum - Alpha Channel

Feb 21^st, 2005 at 1:59am

Batman93210 Offline
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I'm doing a repaint, but the finish is dull. I have figured out how to make the wings chrome, by creating an alpha channel (black). Thats ok for the wings, but how do I get a semi'gloss finsh on the rest of the plane

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Reply #1 - Feb 21^st, 2005 at 11:11am

|| Andy || Offline
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You need to imagine the fuse on the alphachannel..
better still...
Open the alphachannel in the editor, and then make it so you have a outline of the fuse and wings, then colour in the bits you want in the right colour.

Remember to have the alpha the same size as the fuse when ure editing, then resize it to 256x256...

Regards,
Andrew Stokes
http://andrews.f2g.net

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Reply #2 - Feb 21^st, 2005 at 1:46pm

Stratobat Offline
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Hi Batman, Try this out

Take the 24 Bit texture that you've repainted, make a copy of it and open the copy in PSP. Convert that texture to a Greyscale and Save (This texture is now your Alpha Channel). Now paint the various parts on the Alpha Channel using progressively lighter or darker shades of Grey until you think it looks right (The lighter the Grey, the more opaque the texture will be, and visa-versa). Now using DXTBmp combine the Alpha Channel with the 24 Bit texture (Backup these files just incase you need to edit them later) and save in the format your using for the textures (32 Bit, DXT3... etc). Pop the Texture into the Aircraft's Texture folder and fire up FS. If the texture still has to much shine, open the Alpha Channel bitmap again and make the Grey a little lighter. You will probably have to edit the Alpha a few times before you get it right.

Don't worry about reducing the Alpha to 256x256, as it's not necessary!

Regards,
Stratobat

&&&&'If the literal sense makes good sense, seek no other sense lest you come up with nonsense'

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Reply #3 - Feb 21^st, 2005 at 2:18pm

Batman93210 Offline
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Thank you for your help

One question: what is PSP?

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Reply #4 - Feb 21^st, 2005 at 2:42pm

Stratobat Offline
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PSP = Paint Shop Pro

Regards,
Stratobat

&&&&'If the literal sense makes good sense, seek no other sense lest you come up with nonsense'

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Reply #5 - Feb 21^st, 2005 at 3:44pm

Batman93210 Offline
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Will Pixia work? I dont have Paint shop pro.

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Reply #6 - Feb 21^st, 2005 at 3:55pm

Felix/FFDS Offline
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Yes, pixia works fine for this purpose

Felix/FFDS

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Reply #7 - Feb 21^st, 2005 at 4:06pm

Stratobat Offline
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Should work, but I don't think Pixia converts to Greyscale ???

Regards,
Stratobat

&&&&'If the literal sense makes good sense, seek no other sense lest you come up with nonsense'

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Reply #8 - Feb 22^nd, 2005 at 12:05pm

|| Andy || Offline
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I always thought u had to reduce it to 256..
Is that just for performance..
All the alphas ive looked at are in psp..

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Reply #9 - Feb 22^nd, 2005 at 1:50pm

Stratobat Offline
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Quote:

I always thought u had to reduce it to 256..
Is that just for performance..

I don't think there is any performance gain ???

I normally leave then the same size as the repainted texture

Regards,
Stratobat

&&&&'If the literal sense makes good sense, seek no other sense lest you come up with nonsense'

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Reply #10 - Feb 22^nd, 2005 at 11:05pm

Batman93210 Offline
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Stratobat , thank you for your help I finally got it.

Now can I manually paint the greyscale on to the alpha? I downloaded a fee trial of PSP, but at a $100.00 I cant by it. I have Paxia, and MS Paint, but I gess that thay cant convert to a greyscale. Well thanks for the help agen

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Reply #11 - Feb 23^rd, 2005 at 1:25pm

Stratobat Offline
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Hi Batman,

Quote:

Now can I manually paint the greyscale on to the alpha?

The Greyscale image IS the Alpha

Quote:

I have Paxia, and MS Paint, but I gess that thay cant convert to a greyscale. Well thanks for the help agen

Either I'm just blind, or there isn't a Greyscale option in Pixia, but I think I have a workaround for it..

You'll need Pixia (With optional Plugins and Filters found on the Pixia Website installed), MS Paint, DXTBmp and Imagetool.

Take the repainted texture and back it up. Name this backup texture Tex_Backup or something like that. Take the Tex_Backup bitmap and open it in Pixia (Make sure it's 24 Bit and not 32 Bit - Pixia doesn't like 32 Bit). Once in Pixia, look for the Filter Icon (Red & Blue Circle icon in top right corner), press it and look through the Effects for Monotone. Select Monotone and press Execute. A little box will open up giving you a few options, select Black & White. This will convert your colour repainted texture into shades of Grey ranging from Pure White to Pure Black. Save the texture as Tex_Alpha or something like that. Now, take the Tex_Alpha bitmap and open it in Imagetool. Convert the texture into an 8 Bit image (Image... Format... 8 Bit). Now, open the texture in MS Paint and edit the bitmap using various shades of Grey until you think it looks right. Remember, the more White the texture, the more opaque the Alpha will be in the Sim. So Anti-Glare panels, wheels and bit's and pieces that you don't want to be shiny must be painted White or lighter shades of Grey on the Alpha bitmap. Once you have edited the Tex_Alpha bitmap and are satisfied with your work, open the REPAINTED texture in DXTBmp and import the Tex_Alpha bitmap using the Import Alpha Channel option (Alpha... Import Alpha Channel). Once the Alpha's imported, you should be able to see it displayed in the top right-hand box in DXTBmp. Click on Apply Alpha to Image (Alpha... Apply Alpha to Image), untick the Mip Maps - Include When Saving option located below the Alpha Preview window. Now save the texture in whatever format you choose (32 Bit, DXT... etc) and drop it into the Aircraft's Texture Folder.

That's it... You should now be able to see your repainted texture with the custom Alpha Channel in Flight Sim

I tried this method above on a repaint I did of a P-51H Mustang and it seemed to worked, but you might need to experiment with it... Just remember to make backup copies of your repainted texture in another folder on your PC so that if it doesn't work, you still have your repaint

You can always use the Alpha Channel bitmap that comes with the original aircraft, but most people just overpaint the whole bitmap with one shade of grey, so if you want to add details or more/less shine to certain areas, it can be a problem ???

Regards,
Stratobat

&&&&'If the literal sense makes good sense, seek no other sense lest you come up with nonsense'

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Reply #12 - Feb 23^rd, 2005 at 9:02pm

Batman93210 Offline
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Stratobat , Thank you for your time, and help

I understand what you are saying. I downloaded a 90 day free trial of PSP, and I have learned in the past few days working on this repaint how to edit the alpha with yours, and the other folks that have helped me.

I am still learnning about the alpha channel. I understand that the alpha controls how much the finish will shine. So white would be a flat finish, and black would give the airplane a chrome finish. So depending on the degree of shine you want one would have to work between white being a flat finsh, gray, and black being chrome. So my question is. Is this all the alpha controls?

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Reply #13 - Feb 24^th, 2005 at 1:16pm

Stratobat Offline
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Quote:

So my question is. Is this all the alpha controls?

Yip, the Alpha basically controls the shine on reflective textures. Alpha's can also render parts of a 3D model transparent if you paint the area on the textures Pure Black or Pure Green. So for example, if you had a Mirage F1 but wanted to do a repaint of one that didn't have an external In-Flight Refuelling Probe, you would paint over the probe using Pure Green and then tell DXTBmp to give the texture a Pure Green Alpha Channel. This part would now be rendered invisible in FS. The only drawback here is that you would still see the IFR Probe on the ground shadow cast by the aircraft Grin

Regards,
Stratobat

&&&&'If the literal sense makes good sense, seek no other sense lest you come up with nonsense'

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Reply #14 - Feb 24^th, 2005 at 1:47pm

Batman93210 Offline
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Ok, I figured that out by when in doubt click it Grin

, but that's not always the thing to do.

If want'ed to do an American repaint is it necessary to paint the airplane in pure black,and then tell DXTBmp to give the texture a Pure Black Alpha Channel to get the chrome?

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Reply #15 - Feb 25^th, 2005 at 12:49pm

Stratobat Offline
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Hi Batman,

If you want to get a Natural Metal/ Chrome finish, try and get hold of some pictures of metal objects (Google for Metal or Silver or something like that) and use them for the actual textures (Photoreal). Once that's done, give the Alpha Channel a dark shade of Grey and merge it with the repainted textures in DXTBmp.

This should give you reflective Natural Metal/ Chrome textures in FS

Regards,
Stratobat

&&&&'If the literal sense makes good sense, seek no other sense lest you come up with nonsense'

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Reply #16 - Feb 26^th, 2005 at 2:36am

Batman93210 Offline
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Stratobat, thanks for that advice on using the real metal textures, I'll try that on the nexed repaint.

I just finished the repaint on a 747-430M Lufthansa to a British Airways paint sceam, with my wife's help. She hand painted all the ribbits,and seams in, and with your help on working with the alpha channel we got the shine just right. You konw we had the rigth colors for a British Airways paint sceam, but untill we got the alpha channel right it looked like a redneck paint job Grin

, a perimer paint job with all the chrome palished Grin

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Reply #17 - Feb 28^th, 2005 at 7:49pm

Batman93210 Offline
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Hi yall

Do you know where I could find some metal textures?

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Reply #18 - Mar 11^th, 2005 at 11:45pm

Got_FireBall Offline
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Have you seen my F4 corsair Ghost Strike in CFS2 in Alpha Channel black but instead of pure black I used a dark grey. It created a ghostly image check it out.

Also created one that is invisible all you can see is the load out and the pilot

FireBall out

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