Struct MaterialUniforms 

#[repr(C)]
pub struct MaterialUniforms {

    pub roughness: f32,
    pub metallic: f32,
    pub macro_variation: f32,
    pub terrain_blend: f32,
    pub tint: [f32; 3],
    pub _pad2: f32,
    pub emissive: [f32; 3],
    pub secondary_blend_sharpness: f32,
    pub albedo_secondary_index: u32,
    pub normal_secondary_index: u32,
    pub emissive_map_index: u32,
    pub orm_map_index: u32,
    pub alpha_cutoff: f32,
    pub opacity: f32,
    pub transparent: u32,
    pub see_through: u32,
}

Per-draw-call material parameters pushed to the fragment shader at buffer(3). Must stay in sync with the MaterialUniforms struct in every .metal shader.

Fields

roughness: f32

Perceptual roughness [0, 1]: 0 = mirror, 1 = fully diffuse.

metallic: f32

Metallic factor [0, 1]: 0 = dielectric, 1 = metal.

macro_variation: f32

Macro-variation strength [0, 1]; 0 disables the tiling-break noise.

terrain_blend: f32

Terrain-shading blend [0, 1]; 0 disables (default PBR sampling), non-zero switches the shader to a triplanar world-space projection with slope-based rocky-tint blending. See Material::terrain_blend.

tint: [f32; 3]

Linear-space RGB multiplier on the albedo sample.

_pad2: f32

Padding so the field layout matches the shader-side struct.

emissive: [f32; 3]

Additive emission colour in linear space.

secondary_blend_sharpness: f32

Sharpness of the slope-based blend between the primary and the albedo_secondary texture pair. 0 = wide soft gradient; 1 = nearly hard cliff edge. Ignored unless both terrain_blend > 0 and the secondary texture pair is bound.

albedo_secondary_index: u32

Index into the per-draw albedo texture (legacy path) or the bindless texture pool (bindless path) for the slope-shaded secondary albedo. 0 is also the fallback when the material doesn’t declare a secondary texture; the shader’s terrain_blend > 0 && secondary_blend_sharpness > 0 gate keeps it from being sampled in that case.

normal_secondary_index: u32

Companion to albedo_secondary_index for the slope-shaded secondary normal map.

emissive_map_index: u32

Bindless-pool index for the emissive map. 0 means no map: the shader gates on a non-zero index, falling back to the scalar emissive factor.

orm_map_index: u32

Bindless-pool index for the packed occlusion/roughness/metalness map (R = occlusion, G = roughness, B = metalness). 0 means no map: the shader keeps the scalar roughness/metallic and full occlusion.

alpha_cutoff: f32

Alpha-cutout threshold in [0, 1]; 0 disables the test. Non-zero makes the fragment shader discard any texel whose albedo alpha falls below it, which is how foliage and decal cards punch holes while staying in the opaque pass.

opacity: f32

Base surface opacity in [0, 1]; 1 = fully opaque (the default). Only meaningful with transparent: it drives the glass alpha in the transparent pass. Carried on the material so it rides Material -> DrawObject.material to the backend; the opaque main-pass shader ignores it.

transparent: u32

1 when this surface routes through the transparent pass instead of the opaque one (a glass MESH on an RT-capable device); 0 for opaque. A CPU routing flag: the backend reads it to skip the draw in the opaque pass + the RT BLAS and to feed the per-pixel-RT transparent producer. No GPU shader reads it (the opaque skip is decided CPU-side).

see_through: u32

1 when a transparent glass MESH renders as genuinely see-through (Layer 2: the scene behind shows through plus a sharp per-pixel reflection); 0 keeps it as opaque low-roughness reflective glass (Layer 1). Another CPU routing flag (no GPU shader reads it): the see-through producer, the opaque-pass skip, and the RT-BLAS exclude all key off it, so Layer 2 is opt-in per material. Always 0 unless transparent is also 1.

Implementations

impl MaterialUniforms

pub const DEFAULT: MaterialUniforms

Neutral material: matte, non-metallic, white tint, no emission.

Trait Implementations

impl Clone for MaterialUniforms

fn clone(&self) -> MaterialUniforms

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for MaterialUniforms

impl NoUninit for MaterialUniforms