flomonster / easy-gltf Goto Github PK

In GLTF the tangents are 4D vectors with W containing either 1 or -1 to denote the tangent space handedness. During loading, easy-gltf normalises the tangent including that "flag" field. This makes the actual direction part of the tangent incorrect and mangles the flag value

Support for loading the names of the objects would be nice.

Needs a feature flag on the gltf crate.

Draco compression is a almost unnoticeable way to get model sizes down. Does this library support it?

The mesh indices are returned as usize, and that makes them unusable as direct GPU input. Indices usually only allow u16 or u32 data formats.

The provided vertex type isn't repr(C) or Copy, so it's hard to properly feed the data directly to the GPU (fields get shuffled by the compiler). Also it would be nice if it implemented bytemuck's Pod/Zeroable for safe transmuting.

It should look like this:

/// Contains a position, normal and texture coordinates vectors.
#[repr(C)]
#[derive(Clone, Debug, Copy, PartialEq, Default)]
#[cfg_attr(feature = "bytemuck", derive(bytemuck::Pod, bytemuck::Zeroable))]
pub struct Vertex {
    /// Position
    pub position: Vector3<f32>,
    /// Normalized normal
    pub normal: Vector3<f32>,
    /// Tangent normal
    pub tangent: Vector4<f32>,
    /// Texture coordinates
    pub tex_coords: Vector2<f32>,
}

Also there is no need to use cgmath's Vector types, they could be just arrays like [f32; 4] to avoid the cgmath dependency.

Would be convenient to have a function that loads scene from slice instead of only from path.