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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/lua_api.txt | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/doc/lua_api.txt b/doc/lua_api.txt index 5ed84fe9a..08bdba03e 100644 --- a/doc/lua_api.txt +++ b/doc/lua_api.txt @@ -152,6 +152,7 @@ Mod directory structure │ ├── models │ ├── textures │ │ ├── modname_stuff.png + │ │ ├── modname_stuff_normal.png │ │ ├── modname_something_else.png │ │ ├── subfolder_foo │ │ │ ├── modname_more_stuff.png @@ -384,6 +385,36 @@ stripping out the file extension: * e.g. `foomod_foothing.png` * e.g. `foomod_foothing` + +Normalmap Textures +------------------ + +If shaders and bumpmapping or parallax occlusion is enabled, Minetest tries +to load normalmaps. +Those image files have to end with `_normal.png` and start with the same name +as their corresponding texture. +For example a normalmap for `foomod_foothing.png` has to be called +`foomod_foothing_normal.png`. + +The sRGB R, G and B colour values of a normalmap pixel are each directly +mapped from `{0, ..., 255}` to `[-1, 1]` and, taken together, +define the normal vector. +The alpha channel defines the heightmap for parallax occlusion. +To be safe, the alpha values should always be bigger than zero +because the colour values, which define the normal vector, +may be undefined for image formats where colour is discarded in fully +transparent pixels. + +Bumpmapping and parallax occlusion are currently experimental features: + +* Bumpmapping in Minetest happens in an obscure way; there are no light sources + defined in the shaders except the sunlight direction. +* Parallax occlusion with relief-mapping mode does not yet work correctly + together with Minetest's Fastfaces. +* The normalmap files must end with `.png`, so other image files are not + supported. + + Texture modifiers ----------------- |