fix(solids): box and wedge histories framed at the bounding-box centre; no second transform after ACIS lift

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/modules/model/primitive_cmd.rs

@@ -1894,7 +1894,7 @@ impl PrimitiveCommand {
         Some((
             placed,
             solid_history::box_op(
-                self.history_transform_axes(origin, x_axis, y_axis),
+                self.history_transform_axes(box_centre(origin, x_axis, y_axis, length, width, height), x_axis, y_axis),
                 length,
                 width,
                 height,
@@ -2024,7 +2024,7 @@ impl PrimitiveCommand {
         Some((
             placed,
             solid_history::wedge_op(
-                self.history_transform_axes(origin, x_axis, y_axis),
+                self.history_transform_axes(box_centre(origin, x_axis, y_axis, length, width, height), x_axis, y_axis),
                 length,
                 width,
                 height,
@@ -3714,3 +3714,9 @@ fn wire(name: &str, points: Vec<[f32; 3]>) -> WireModel {
         ..Default::default()
 }
 }
+
+/// Box and wedge histories are framed at the centre of their bounding box,
+/// as the reference stores them (lengths stay positive).
+fn box_centre(origin: DVec3, x_axis: DVec3, y_axis: DVec3, length: f64, width: f64, height: f64) -> DVec3 {
+    origin + x_axis * (length * 0.5) + y_axis * (width * 0.5) + DVec3::Z * (height * 0.5)
+}

src/scene/convert/acis_kernel.rs

@@ -31,23 +31,14 @@ pub fn tessellate_sat(
     if bodies.is_empty() {
         return None;
     }
+    // The kernel's lift already applies each body's transform record; its
+    // scale still sets the tessellation tolerance.
     let mut placed_bodies = Vec::with_capacity(bodies.len());
     for body in bodies {
         let source = body.provenance.source()?;
         let transform = body_transform(document, source.index() as usize).ok()?;
         let placement_scale = transform.map_or(1.0, |(_, _, scale)| scale.abs());
-        let placed = if let Some((matrix, translation, scale)) = transform {
-            let placement = brep::Placement {
-                x_axis: [scale * matrix[0], scale * matrix[1], scale * matrix[2]],
-                y_axis: [scale * matrix[3], scale * matrix[4], scale * matrix[5]],
-                z_axis: [scale * matrix[6], scale * matrix[7], scale * matrix[8]],
-                origin: translation,
-            };
-            brep::transform(&body, &placement)?
-        } else {
-            body
-        };
-        placed_bodies.push((placed, placement_scale));
+        placed_bodies.push((body, placement_scale));
     }
     let bodies = placed_bodies;
     let resolution = if facet_res.is_finite() && facet_res > 0.0 {

src/scene/convert/solid3d_tess.rs

@@ -1,6 +1,6 @@
 use codec::entities::acis::{SabReader, SatBody, SatDocument};
 use codec::entities::{Body, Region, Solid3D, Surface};
-use kernel::brep::{self, Body as KernelBody};
+use kernel::brep::Body as KernelBody;
 
 use crate::scene::model::mesh_model::{MeshLodSet, MeshModel};
 
@@ -179,21 +179,8 @@ pub(crate) fn kernel_acis_body(acis: &codec::entities::AcisData) -> Option<Kerne
     if !loss.is_empty() || bodies.len() != 1 {
         return None;
     }
-    let body = bodies.pop()?;
-    let source = body.provenance.source()?;
-    let Some((matrix, translation, scale)) = body_transform(&sat, source.index() as usize).ok()?
-    else {
-        return Some(body);
-    };
-    brep::transform(
-        &body,
-        &brep::Placement {
-            x_axis: [scale * matrix[0], scale * matrix[1], scale * matrix[2]],
-            y_axis: [scale * matrix[3], scale * matrix[4], scale * matrix[5]],
-            z_axis: [scale * matrix[6], scale * matrix[7], scale * matrix[8]],
-            origin: translation,
-        },
-    )
+    // The kernel's lift already applies the body's transform record.
+    bodies.pop()
 }
 
 fn remap_acis_material_bindings(

src/scene/model/solid_history.rs

@@ -278,7 +278,7 @@ pub fn reference_point(operation: &SolidHistoryOperation) -> Option<glam::DVec3>
     match operation {
         SolidHistoryOperation::Box(value) | SolidHistoryOperation::Wedge(value) => world_point(
             value.base.transform,
-            [value.length * 0.5, value.width * 0.5, 0.0],
+            [0.0, 0.0, -value.height * 0.5],
         ),
         SolidHistoryOperation::Sphere(value) => {
             world_point(value.base.transform, [0.0, 0.0, 0.0])
@@ -1615,9 +1615,10 @@ pub fn primitive_properties(
     ) {
         return Vec::new();
     }
-    let Some(operation) = primitive_property_operation(document, handle) else {
+    let Some(mut operation) = primitive_property_operation(document, handle) else {
         return brep_properties(document, handle);
     };
+    corner_frame(&mut operation);
     match &operation {
         SolidHistoryOperation::Box(value) => {
             rectangular_properties(document, handle, value, "Box")
@@ -2414,6 +2415,17 @@ pub fn apply_primitive_property(
     operation: &mut SolidHistoryOperation,
     field: &str,
     value: &str,
+) -> bool {
+    corner_frame(operation);
+    let applied = apply_primitive_property_at_corner(operation, field, value);
+    centre_frame(operation);
+    applied
+}
+
+fn apply_primitive_property_at_corner(
+    operation: &mut SolidHistoryOperation,
+    field: &str,
+    value: &str,
 ) -> bool {
     if let SolidHistoryOperation::Brep(brep_value) = operation {
         if let Some(applied) = apply_brep_position_property(brep_value, field, value) {
@@ -3460,6 +3472,9 @@ pub fn primitive_grips(
     let Some(operation) = document.solid_history_operation(handle) else {
         return Vec::new();
     };
+    let mut operation = operation.clone();
+    corner_frame(&mut operation);
+    let operation = &operation;
     if let SolidHistoryOperation::Fillet(value) = operation {
         let Some(radius) = value.radii.first().copied() else {
             return Vec::new();
@@ -3743,6 +3758,17 @@ pub fn apply_primitive_grip(
     operation: &mut SolidHistoryOperation,
     grip_id: usize,
     apply: GripApply,
+) -> bool {
+    corner_frame(operation);
+    let applied = apply_primitive_grip_at_corner(operation, grip_id, apply);
+    centre_frame(operation);
+    applied
+}
+
+fn apply_primitive_grip_at_corner(
+    operation: &mut SolidHistoryOperation,
+    grip_id: usize,
+    apply: GripApply,
 ) -> bool {
     if let SolidHistoryOperation::Revolve(value) = operation {
         if let Some(index) = grip_id.checked_sub(GRIP_REVOLVE_PROFILE_FIRST) {
@@ -4138,3 +4164,23 @@ pub fn chamfer_op(
         ..SolidHistoryChamfer::default()
     })
 }
+
+/// Box and wedge histories are framed at the centre of their bounding box,
+/// as the reference stores them; the editing code here works in the frame at
+/// the base corner. These move a box or wedge between the two frames.
+fn corner_frame(operation: &mut SolidHistoryOperation) {
+    shift_rectangular_frame(operation, -0.5);
+}
+
+fn centre_frame(operation: &mut SolidHistoryOperation) {
+    shift_rectangular_frame(operation, 0.5);
+}
+
+fn shift_rectangular_frame(operation: &mut SolidHistoryOperation, factor: f64) {
+    if let SolidHistoryOperation::Box(value) | SolidHistoryOperation::Wedge(value) = operation {
+        if let Some(current) = matrix(value.base.transform) {
+            let half = glam::DVec3::new(value.length, value.width, value.height) * factor;
+            value.base.transform = (current * glam::DMat4::from_translation(half)).to_cols_array();
+        }
+    }
+}