fixed debug_lines build and transform nan issue

CHANGELOG.MD

@@ -0,0 +1,6 @@
+# Version 0.1.0
+- Initial version
+
+# Version 0.1.1
+- Fixed build issue when using the debug_lines feature
+- Fixed transforms giong to NaN when an exact match is found

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bevy_mod_inverse_kinematics"
-version = "0.1.0"
+version = "0.1.1"
 authors = ["Bram Buurlage <brambuurlage@gmail.com>"]
 edition = "2021"
 categories = ["game-engines", "graphics", "rendering"]

src/lib.rs

@@ -29,7 +29,7 @@ pub struct IkConstraint {
 impl Plugin for InverseKinematicsPlugin {
     fn build(&self, app: &mut App) {
         #[cfg(feature = "debug_lines")]
-        app.add_plugin(DebugLinesPlugin::default());
+        app.add_plugin(bevy_prototype_debug_lines::DebugLinesPlugin::default());
         app.add_system_to_stage(
             CoreStage::PostUpdate,
             solver::inverse_kinematics_system

src/solver.rs

@@ -1,5 +1,5 @@
-use bevy::prelude::*;
 use bevy::ecs::query::QueryEntityError;
+use bevy::prelude::*;
 #[cfg(feature = "debug_lines")]
 use bevy_prototype_debug_lines::{DebugLines, DebugLinesPlugin};
 
@@ -56,6 +56,9 @@ impl IkConstraint {
             let start = transforms.get(joints[self.chain_length])?.1.translation();
             let pole_target = transforms.get(pole_target)?.1.translation();
 
+            #[cfg(feature = "debug_lines")]
+            debug_lines.line_colored(start, target, 0.0, Color::WHITE);
+
             let tangent = (target - start).normalize();
             let axis = (pole_target - start).cross(tangent);
             let normal = tangent.cross(axis).normalize();
@@ -98,6 +101,25 @@ impl IkConstraint {
         #[cfg(feature = "debug_lines")] debug_lines: &mut DebugLines,
     ) -> Result<GlobalTransform, QueryEntityError> {
         let (&transform, &global_transform) = transforms.get(chain[0])?;
+        #[cfg(feature = "debug_lines")]
+        {
+            let p = global_transform.translation();
+            debug_lines.line_colored(p, global_transform.mul_vec3(Vec3::X * 0.1), 0.0, Color::RED);
+            debug_lines.line_colored(
+                p,
+                global_transform.mul_vec3(Vec3::Y * 0.1),
+                0.0,
+                Color::GREEN,
+            );
+            debug_lines.line_colored(
+                p,
+                global_transform.mul_vec3(Vec3::Z * 0.1),
+                0.0,
+                Color::BLUE,
+            );
+            debug_lines.line_colored(p, global_transform.mul_vec3(normal), 0.0, Color::YELLOW);
+        }
+
         if chain.len() == 1 {
             return Ok(global_transform);
         }
@@ -114,7 +136,9 @@ impl IkConstraint {
 
             let base = Quat::from_rotation_arc(normal.normalize(), Vec3::Z);
 
-            let forward = (target - from_position).normalize();
+            let forward = (target - from_position)
+                .try_normalize()
+                .unwrap_or(pt.tangent);
             let up = forward.cross(pt.normal).normalize();
             let right = up.cross(forward);
             let orientation = Mat3::from_cols(right, up, forward) * Mat3::from_rotation_z(pt.angle);
@@ -129,15 +153,6 @@ impl IkConstraint {
         };
         let translation = target - rotation.mul_vec3(normal);
 
-        #[cfg(feature = "debug_lines")]
-        {
-            let p = translation;
-            debug_lines.line_colored(p, p + rotation.mul_vec3(Vec3::X * 0.1), 0.0, Color::RED);
-            debug_lines.line_colored(p, p + rotation.mul_vec3(Vec3::Y * 0.1), 0.0, Color::GREEN);
-            debug_lines.line_colored(p, p + rotation.mul_vec3(Vec3::Z * 0.1), 0.0, Color::BLUE);
-            debug_lines.line_colored(p, p + rotation.mul_vec3(normal), 0.0, Color::YELLOW);
-        }
-
         // recurse to target the parent towards the current translation
         let parent_global_transform = Self::solve_recursive(
             &chain[1..],
@@ -167,4 +182,4 @@ impl IkConstraint {
 
         Ok(*global_transform)
     }
-}
+}