How to make dynamic light affect PNG middle textures

[WARCHILD_89]

To anyone using the flashlight by "the zombie killer" or the lamplight from the "Lasting Light" mod or something similiar, here is one thing I discovered and it helps, when light does not affect middle textures:

It seems to me that the reason is the image format!

I created a texture that shows a plant in PNG format with transparency:
https://fbcdn-sphotos-d-a.akamaihd.net/ ... 7368_n.jpg


pointing the flashlight on it does have no effect:
https://fbcdn-sphotos-h-a.akamaihd.net/ ... 8977_n.jpg


After trying around with 3d floors and linedefs, I had a new idea, I tested it on an original Texture from doom 2 that also has transparent areas and I got this:
https://fbcdn-sphotos-b-a.akamaihd.net/ ... 3538_n.jpg

so to get a dynamic light affecting my tree, I have to convert the image to doom format and it works, the tree is being affected
(something went wrong with the colors, but this is not the point now):
https://fbcdn-sphotos-g-a.akamaihd.net/ ... 9604_n.jpg

[Gez]

Not so much the image format (everything is converted to an internal bitmap-like format anyway) but the image properties. Namely, full alpha channel or not. The Doom graphics format has no alpha channel to speak off: pixels are either fully transparent or fully opaque.

[Nash]

How come the dynamic light only illuminates textures without full alpha? Seems like a bug...

[WARCHILD_89]

I wonder how I can make an image behave like the doom textures, does anybody know what kind of image format to use?

[Marrub]

I wonder how I can make an image behave like the doom textures, does anybody know what kind of image format to use?

I think there's a way to remove the full alpha channel (and just have binary opacity) from a PNG to make it act like a doom-format texture, but I don't exactly know how. Color Quantizer on very slow setting might remove it if it isn't needed.

[WARCHILD_89]

I finally did it. The thing is to safe the png file not with transparency, take a color instead. I took white for example.

Then, convert the png in SLADE 3 to PNG Truecolor, (otherwise the image turns black and white) set the transparency color to white (in my case) and there you go, all the white areas in the image are transparent now!
https://fbcdn-sphotos-a-a.akamaihd.net/ ... 6727_n.jpg

[Marrub]

Yep, that's a way of doing it. Still seems like a bug though.

[Gez]

How come the dynamic light only illuminates textures without full alpha? Seems like a bug...

Oh, it is. I'm just pointing out the real cause of the discrepancy. There are different paths to render images with full alpha and images without full alpha.