Struct Triangle 

pub struct Triangle {
    pub v0: Point3<f64>,
    pub v1: Point3<f64>,
    pub v2: Point3<f64>,
}

Triangle definition

Fields

v0: Point3<f64>

v1: Point3<f64>

v2: Point3<f64>

Implementations

impl Triangle

pub fn new(v0: Point3<f64>, v1: Point3<f64>, v2: Point3<f64>) -> Self

Create a new triangle

pub fn normal(&self) -> Vector3<f64>

Calculate triangle normal.

Degenerate triangles get +Z, never NaN. A zero-area (collapsed or exactly collinear) triangle has a zero-length cross product, and the plain normalize() this used to call is v / |v| — i.e. 0.0 / 0.0, which is NaN in every component. Those NaNs were written verbatim into Mesh::normals by add_triangle_to_mesh (the only production caller of this method, via ClippingProcessor::clip_mesh), and they SURVIVED the mesh-hygiene pass: clean_degenerate / drop_thin_triangles rewrites only indices, so the degenerate triangle’s vertices stay in positions / normals as ORPHANS carrying NaN. Six of duplex.ifc’s material-layer wall slices shipped 81 NaN normal components that way, which the @ifc-lite/provenance node-hash domain check rightly rejects (every NaN bit pattern collapses to one quiet NaN when serialized, so accepting them would give distinct payloads the same hash).

+Z is this crate’s established convention for an undefined normal — the same fallback csg::normals::calculate_normals and mesh::weld_impl’s average-normals path already use — so a consumer that meets one meets them all. It is stated in the KERNEL’s own Z-up frame, like every other normal this crate writes, so a viewer that converts to Y-up reads it back as +Y; that is the conversion doing its job, not a second convention. The value is arbitrary but must be a FIXED unit vector: a zero normal would just re-create the division by zero in any shader or exporter that re-normalizes.

Non-degenerate triangles are unaffected, bit-for-bit: try_normalize(0.0) returns Some(v.unscale(|v|)) for every |v| > 0, which is exactly what normalize() computed. The extra is_finite check covers the astronomically-unlikely underflow case where |v| rounds to zero from non-zero components (division would yield ±Inf, also out of domain).

pub fn cross_product(&self) -> Vector3<f64>

Calculate the cross product of edges, which is twice the area vector.

Returns a Vector3<f64> perpendicular to the triangle plane. For degenerate/collinear triangles, returns the zero vector. Use is_degenerate() or try_normalize() on the result if you need to detect and handle degenerate cases.

pub fn area(&self) -> f64

Calculate triangle area (half the magnitude of the cross product).

pub fn is_degenerate(&self, epsilon: f64) -> bool

Check if triangle is degenerate (zero area, collinear vertices).

Uses try_normalize on the cross product with the specified epsilon. Returns true if the cross product cannot be normalized (i.e., degenerate).

Trait Implementations

impl Clone for Triangle

fn clone(&self) -> Triangle

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Triangle

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.