alpha map

[crackhead]

hi i know theres a tutorial on hl2world on making an alpha map but this is

kind of different from what im doing and doesnt really help. i have made a

model of a bamboo tree. the tree part is textured and then there are 3

square sheets in different angles at the top. now i have my texture on these

squares that is of green leaves and a white background. now i need the

white part to be transparent so i have made another texture that has the

parts that are to be seen as pure white and the background which should be

transparent as pure black. now im just not sure how to compile these

textures so that it uses the second image as an alphamap. can anybody

show me the code i should put in the vmt file that says that my second

image needs to be used as an alpha map. also do i need to put "$translucent"

1 in and also "$nocull" 1 and what does nocull meen?

 

[pur3r4ge]

Don't use them as 2 images, add the black and white image to the alpha channel of the main texture in photoshop, then export it as a 32 bit tga. You'll want to invert it as well, as it doesn't draw the black, but draws the white.

To do this: open the texture in PS, and next to the layers tab, there's a channels tab. Click on it, then click the "new layer" button at the bottom. Paste your B&W image into this layer. Save as... tga, then choose 32bit when it prompts you. Recompile your new tga. Add the "$translucent" 1 and "$nocull" 1 to the vmt. You'll also want to add "$alphatest" 1

nocull means no backface culling, which refers to when the backside of a polygon is not drawn. If you don't add that, your leaves will only be visible from one side.

 

[crackhead]

ok i use paintshop pro i know its rubbish but i havnt got round to digging photoshop out of my big pile. ill try doing the same thing on paintshop

 

[Some0ne]

im not entirely sure about this but i think it is possible to use a seperate image as an alpha map but it is easier just to put it all into the one.

and i dont know the command(s) to tell the VMT to use this alpha image so dont ask.

 

[crackhead]

i think i just need to put $alphamap \whateva.vtf