fem: pyramid5 element (solver, quality, decks, VTK)

A five-node pyramid, the conforming transition between a hexahedron's face
and tetrahedra: Bedrosian's rational shape functions with a collapsed (Duffy)
Gauss rule, a certified Jacobian on the base square with exact volume, a
scaled Jacobian, C3D5 / CPYRAM / LS-DYNA degenerate solid, VTK_PYRAMID and
the binary mesh code 13. A distorted hex8-pyramid5-tet4 transition mesh
passes the patch test and uniaxial tension exactly.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/engine/src/cmd/forms.rs

@@ -1384,6 +1384,7 @@ pub const ELEMENT_ADD: &[Field] = &[
             ("tet4", "tet4"),
             ("tet10", "tet10"),
             ("wedge6", "wedge6"),
+            ("pyramid5", "pyramid5"),
             ("hex8", "hex8"),
             ("hex20", "hex20"),
         ],

crates/engine/src/cmd/mesh.rs

@@ -40,7 +40,7 @@ pub const NODE_REMOVE: CommandSpec = CommandSpec {
 pub const ELEMENT_ADD: CommandSpec = CommandSpec {
     id: "mesh.element.add",
     label: "Add Element",
-    params: r#"{"label": 1, "kind": "rod2|beam2|tri3|tri6|quad4|quad8|tet4|tet10|wedge6|hex8|hex20", "nodes": [labels]} — adds or replaces"#,
+    params: r#"{"label": 1, "kind": "rod2|beam2|tri3|tri6|quad4|quad8|tet4|tet10|wedge6|pyramid5|hex8|hex20", "nodes": [labels]} — adds or replaces"#,
     form: Some(super::forms::ELEMENT_ADD),
     kind: CommandKind::Model,
     requires: &[Requirement::Nodes],

crates/engine/src/cmd/mirror.rs

@@ -23,7 +23,7 @@ use crate::{CommandKind, CommandSpec, EngineError, Result, Session};
 pub const MIRROR: CommandSpec = CommandSpec {
     id: "mesh.mirror",
     label: "Mirror Mesh",
-    params: r#"{"plane": "Sym" (a datum plane) or {"point": [x, y, z], "normal": [nx, ny, nz]}, "bodies": ["Part/a"] (default: every body the mesh is tagged with), "as": {"Part/a": "Part/b"} (optional: the body each image is; default the design's body at the reflected place, else "<body>/mirror")} — replaces each image body's mesh (as mesh.tet.generate) with the reflection of the bodies' elements (tet4, tet10, wedge6, hex8, hex20) across the plane: each copy right-handed (its nodes in reflected order), the copies of the nodes on the plane merged with them so the mesh is conforming there, geometry tags carried to the image (its body, and on it the faces the reflected faces lie on, so sets by face name select both halves). Reports the elements and nodes added, the nodes shared on the plane and each image's body"#,
+    params: r#"{"plane": "Sym" (a datum plane) or {"point": [x, y, z], "normal": [nx, ny, nz]}, "bodies": ["Part/a"] (default: every body the mesh is tagged with), "as": {"Part/a": "Part/b"} (optional: the body each image is; default the design's body at the reflected place, else "<body>/mirror")} — replaces each image body's mesh (as mesh.tet.generate) with the reflection of the bodies' elements (tet4, tet10, wedge6, pyramid5, hex8, hex20) across the plane: each copy right-handed (its nodes in reflected order), the copies of the nodes on the plane merged with them so the mesh is conforming there, geometry tags carried to the image (its body, and on it the faces the reflected faces lie on, so sets by face name select both halves). Reports the elements and nodes added, the nodes shared on the plane and each image's body"#,
     form: Some(super::forms::MIRROR),
     kind: CommandKind::Model,
     requires: &[Requirement::Mesh],

crates/engine/src/view.rs

@@ -28,6 +28,7 @@ pub struct Palette {
     pub hex: Rgb,
     pub tet: Rgb,
     pub wedge: Rgb,
+    pub pyramid: Rgb,
     pub shell: Rgb,
     pub line_element: Rgb,
     pub mesh_edge: Rgb,
@@ -61,6 +62,7 @@ impl Palette {
         hex: Rgb(0x78, 0x9c, 0xc0),
         tet: Rgb(0x80, 0xb4, 0x8a),
         wedge: Rgb(0xc0, 0xaa, 0x78),
+        pyramid: Rgb(0xa8, 0x90, 0xc8),
         shell: Rgb(0xc0, 0x8c, 0x78),
         line_element: Rgb(0xc8, 0x8c, 0x1e),
         mesh_edge: Rgb(0x1e, 0x23, 0x2a),
@@ -100,6 +102,7 @@ impl Palette {
             ElementKind::Hex8 | ElementKind::Hex20 => self.hex,
             ElementKind::Tet4 | ElementKind::Tet10 => self.tet,
             ElementKind::Wedge6 => self.wedge,
+            ElementKind::Pyramid5 => self.pyramid,
             ElementKind::Tri3 | ElementKind::Tri6 | ElementKind::Quad4 | ElementKind::Quad8 => self.shell,
             ElementKind::Rod2 | ElementKind::Rod3 | ElementKind::Beam2 => self.line_element,
         }