Alpha Map
Blitz3D Forums/Blitz3D Programming/Alpha Map
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| exactly how and in what package would you be able to to draw a texture that included an alpha map? By that I mean a texture with a visible image on it and also alpha information in the same texture. |
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| The "how" is a big question (plus it is VERY specific to the graphics package being used; ask it again once you have decided on an art tool) but the second question is easy enough. The three most commonly mentioned art tools (in decending order of price from several hundred to free) are Photoshop, PaintShop Pro, and GIMP. All three are capable of creating images with an alpha channel. |
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| Right, I have photoshop and as far as I can see PNG is the only file format Blitz supports that can contain an alpha channel, but I can't get it to save it. |
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| TGAs can handle alpha and blitz loads them fine. |
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| Under "Channels" create a new channel...it should be named 'alpha 1' In the alpha channel, whatever is black will be invisible, grey is semi-transparent, and white will be solid. Save as png or tga and load into blitz with alpha flag. |
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| Actually that is not a good way to do alpha transparency with PNG file format. That is exactly how it is done with TGA images but for PNG that procedure results in ugly white halos around the image because the transparent parts of the image (which get blended around the edges due to anti-aliasing) become white. For PNG alpha transparency you will want to make the image a new layer, delete the Background layer, add a mask to the image layer, and then paste your alpha channel to the layer mask channel. |
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