Extrude's start_offset says which way it goes: along the sketch normal, also with direction: negative (where a positive offset starts on the far side of the sketch from the extrusion)

The params doc listed start_offset? with no description, and an extrude in direction negative with a positive start offset surprised a user. The behaviour is unchanged (an offset start plane, as in Fusion); the params doc of solid.extrude and the Extent field doc say so.

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

crates/doc/src/document.rs

@@ -125,7 +125,8 @@ pub struct Extent {
     /// Optional second side distance (two-sided extrude), along the negative normal.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub distance2: Option<String>,
-    /// Start offset from the sketch plane (expression).
+    /// Start offset from the sketch plane (expression), along the sketch normal whatever the
+    /// direction.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub start_offset: Option<String>,
     /// Through all bodies in the direction(s) instead of `distance`.

crates/engine/src/cmd/features.rs

@@ -13,7 +13,7 @@ pub static COMMANDS: &[CommandSpec] = &[
         .at("SOLID", "CREATE")
         .icon("extrude")
         .key("E")
-        .params("distance: expr (or through_all: true); taper?: angle expr; sketch?: id|name (default: active or last sketch); profiles?: all | [index] | [[curve ids]] | [{point:[x,y]}]; face?: [x,y,z] (extrude a planar body face instead of a sketch profile); direction?: positive|negative|symmetric; distance2?; start_offset?; to?: [x,y,z] (To Object: a face, vertex or point; to_offset?: expr past it); from?: [x,y,z] (From Object: start at that face or point); operation?: new|join|cut|intersect|auto (cut into a body, join out of one, else new); targets?: [body]; name?; body_name?"),
+        .params("distance: expr (or through_all: true); taper?: angle expr; sketch?: id|name (default: active or last sketch); profiles?: all | [index] | [[curve ids]] | [{point:[x,y]}]; face?: [x,y,z] (extrude a planar body face instead of a sketch profile); direction?: positive|negative|symmetric; distance2?; start_offset?: expr (along the sketch normal, also with direction: negative); to?: [x,y,z] (To Object: a face, vertex or point; to_offset?: expr past it); from?: [x,y,z] (From Object: start at that face or point); operation?: new|join|cut|intersect|auto (cut into a body, join out of one, else new); targets?: [body]; name?; body_name?"),
     CommandSpec::new("solid.revolve", "Revolve", revolve)
         .at("SOLID", "CREATE")
         .icon("revolve")