It requires an alpha channel. It creates solid borders around objects though - everything below 50% opacity is removed, and everything above is treated as 100%.
If that isn't good enough for you, I think what you want can't be done, unless you're okay with the lightmap being completely visible over the entire surface.
You can't have the lightmap fade the same as the texture underneath it, unless you cut out that part of the lightmap page and photoshop it - not very practical.
Attachment:
eraser_lq.jpg [ 160.71 KB | Viewed 281 times ]
Code:
textures/eraser/blendFunc
{
surfaceparm trans
{
map textures/eraser/eraser.tga
blendFunc GL_DST_COLOR GL_ONE
rgbGen identity
}
{
map $lightmap
rgbGen identity
blendFunc filter
tcGen lightmap
}
}
{
surfaceparm trans
{
map textures/eraser/eraser.tga
blendFunc GL_DST_COLOR GL_ONE
rgbGen identity
}
{
map $lightmap
rgbGen identity
blendFunc filter
tcGen lightmap
}
}
Code:
textures/eraser/alphaFunc
{
surfaceparm trans
{
map textures/eraser/eraser2.tga
alphaFunc GE128
rgbGen identity
depthWrite
}
{
map $lightmap
rgbGen identity
blendFunc filter
depthFunc equal
tcGen lightmap
}
}
{
surfaceparm trans
{
map textures/eraser/eraser2.tga
alphaFunc GE128
rgbGen identity
depthWrite
}
{
map $lightmap
rgbGen identity
blendFunc filter
depthFunc equal
tcGen lightmap
}
}
The blendFunc image is a jpg with some white lines and a gaussian blur applied, to ensure there's a gradient. I then warped it, duplicated one of the channels for alpha, and saved it as targa.
As far as I know, there's no way to inherit depth from blendFuncs because they don't have depth or they're weird somehow (?). AlphaFunc is great for this, because it lets you use the depth buffer info for other stages (?). I understand the concept but I don't know the words to apply to it lol.