feat: Add helper methods to create matrix4 with sensible defaults

packages/flame_3d/lib/src/game/transform_3d.dart

@@ -51,6 +51,41 @@ class Transform3D extends ChangeNotifier {
     return Transform3D()..setFromMatrix4(matrix);
   }
 
+  /// Creates a [Transform3D] from the given broken down
+  /// parameters and sensible defaults:
+  /// - [position] defaults to no translation;
+  /// - [rotation] defaults to no rotation;
+  /// - [scale] defaults to no scaling.
+  factory Transform3D.compose({
+    Vector3? position,
+    Quaternion? rotation,
+    Vector3? scale,
+  }) {
+    final matrix = matrix4(
+      position: position,
+      rotation: rotation,
+      scale: scale,
+    );
+    return Transform3D.fromMatrix4(matrix);
+  }
+
+  /// Creates a transform-3d-type [Matrix4] from the given broken down
+  /// parameters and sensible defaults:
+  /// - [position] defaults to no translation;
+  /// - [rotation] defaults to no rotation;
+  /// - [scale] defaults to no scaling.
+  static Matrix4 matrix4({
+    Vector3? position,
+    Quaternion? rotation,
+    Vector3? scale,
+  }) {
+    return Matrix4.compose(
+      position ?? Vector3.zero(),
+      rotation ?? Quaternion.identity(),
+      scale ?? Vector3.all(1),
+    );
+  }
+
   /// Clone of this.
   Transform3D clone() => Transform3D.copy(this);
 

packages/flame_3d/test/transform_3d_test.dart

@@ -46,5 +46,39 @@ void main() {
         closeToMatrix4(matrix2, epsilon),
       );
     });
+
+    test('can create matrix4 using some parameters with sensible defaults', () {
+      final matrix1 = Transform3D.matrix4(
+        position: Vector3(1, 2, 3),
+      );
+      final transform1 = Transform3D.fromMatrix4(matrix1);
+      expect(transform1.position, closeToVector3(Vector3(1, 2, 3), epsilon));
+      expect(
+        transform1.rotation,
+        closeToQuaternion(Quaternion.identity(), epsilon),
+      );
+      expect(transform1.scale, closeToVector3(Vector3.all(1), epsilon));
+
+      final transform2 = Transform3D.compose(
+        rotation: Quaternion(0.1, 0.2, 0.3, 0.4).normalized(),
+      );
+      expect(transform2.position, closeToVector3(Vector3.zero(), epsilon));
+      expect(
+        transform2.rotation,
+        closeToQuaternion(Quaternion(0.1, 0.2, 0.3, 0.4).normalized(), epsilon),
+      );
+      expect(transform2.scale, closeToVector3(Vector3.all(1), epsilon));
+
+      final matrix3 = Transform3D.matrix4(
+        scale: Vector3(4, 5, 6),
+      );
+      final transform3 = Transform3D()..setFromMatrix4(matrix3);
+      expect(transform3.position, closeToVector3(Vector3.zero(), epsilon));
+      expect(
+        transform3.rotation,
+        closeToQuaternion(Quaternion.identity(), epsilon),
+      );
+      expect(transform3.scale, closeToVector3(Vector3(4, 5, 6), epsilon));
+    });
   });
 }