How to convert a Skinned Mesh (.skn .skl) to glTF

Go to the Skinned Mesh to glTF page in the program. There you can select the simple skin (.skn) file along with its skeleton (.skl) file.

lol2gltf lets you export just the simple skin as a glTF file but you can also import the skeleton to make the mesh rigged.

Importing the skeleton will also allow you to import animation files. lol2gltf will re-sample the imported animation files using their original FPS to mimic the way that they are processed by the engine. This will result in butter smooth animations in the created glTF file. Keep in mind that the generated glTF animation will be a linear sampler and not a cubic one (since it is re-sampled in discrete time), this means that there will be a keyframe for each frame of the animation.

You are also able to select the texture for each simple skin primitive. This texture will get converted into a .png image in the created glTF file.

Important: The glTF specification prohibits the usage of the mesh's transform if the mesh is bound to a skin. This means that lol2gltf exports the assets as-is without flipping the X axis, so if you want to have a correct handedness, you will have to flip the root node/scene across the X axis.