clean some remaining things up

irr/include/SkinnedMesh.h

@@ -306,8 +306,6 @@ public:
 		std::optional<std::string> Name;
 
 		//! Local transformation to be set by loaders. Mutated by animation.
-		//! If a matrix is used, this joint **must not** be animated,
-		//! because then the unique decomposition into translation, rotation and scale need not exist!
 		using VariantTransform = std::variant<core::Transform, core::matrix4>;
 		VariantTransform transform{core::Transform{}};
 
@@ -316,7 +314,10 @@ public:
 				return transform;
 
 			if (std::holds_alternative<core::matrix4>(transform)) {
-				// .x lets animations override matrix transforms entirely.
+				// .x lets animations override matrix transforms entirely,
+				// which is what we implement here.
+				// .gltf does not allow animation of nodes using matrix transforms.
+				// Note that a decomposition into a TRS transform need not exist!
 				core::Transform trs;
 				keys.updateTransform(frame, trs);
 				return {trs};

irr/include/Transform.h

@@ -15,18 +15,6 @@ struct Transform {
 	quaternion rotation;
 	vector3df scale{1};
 
-	// Tries to decompose the matrix, if there is one.
-	static Transform decompose(const core::matrix4 &mat)
-	{
-		auto scale = mat.getScale();
-		return {
-			mat.getTranslation(),
-			quaternion(mat.getRotationRadians(scale)),
-			scale,
-		};
-	}
-
-
 	Transform interpolate(Transform to, f32 time) const
 	{
 		core::quaternion interpolated_rotation;

irr/src/CAnimatedMeshSceneNode.cpp

@@ -4,7 +4,6 @@
 
 #include "CAnimatedMeshSceneNode.h"
 #include "CBoneSceneNode.h"
-#include "EDebugSceneTypes.h"
 #include "IVideoDriver.h"
 #include "ISceneManager.h"
 #include "S3DVertex.h"
@@ -282,14 +281,15 @@ void CAnimatedMeshSceneNode::render()
 		if (DebugDataVisible & scene::EDS_SKELETON) {
 			if (Mesh->getMeshType() == EAMT_SKINNED) {
 				// draw skeleton
-
-				/*for (auto *joint : ((SkinnedMesh *)Mesh)->getAllJoints()) {
-					for (const auto *childJoint : joint->Children) {
-						driver->draw3DLine(joint->GlobalAnimatedMatrix.getTranslation(),
-								childJoint->GlobalAnimatedMatrix.getTranslation(),
+				const auto &joints = (static_cast<SkinnedMesh *>(Mesh))->getAllJoints();
+				for (u16 i = 0; i < PerJoint.GlobalMatrices.size(); ++i) {
+					const auto translation = PerJoint.GlobalMatrices[i].getTranslation();
+					if (auto pjid = joints[i]->ParentJointID) {
+						const auto parent_translation = PerJoint.GlobalMatrices[*pjid].getTranslation();
+						driver->draw3DLine(parent_translation, translation,
 								video::SColor(255, 51, 66, 255));
 					}
-				}*/
+				}
 			}
 		}
 

irr/src/SkinnedMesh.cpp

@@ -13,7 +13,6 @@
 #include "matrix4.h"
 #include "os.h"
 #include "vector3d.h"
-#include <cassert>
 #include <cstddef>
 #include <variant>
 #include <vector>
@@ -62,7 +61,7 @@ void SkinnedMesh::setAnimationSpeed(f32 fps)
 using VariantTransform = SkinnedMesh::SJoint::VariantTransform;
 std::vector<VariantTransform> SkinnedMesh::animateMesh(f32 frame)
 {
-	assert(HasAnimation);
+	_IRR_DEBUG_BREAK_IF(!HasAnimation);
 	std::vector<VariantTransform> result;
 	result.reserve(AllJoints.size());
 	for (auto *joint : AllJoints)
@@ -73,7 +72,7 @@ std::vector<VariantTransform> SkinnedMesh::animateMesh(f32 frame)
 core::aabbox3df SkinnedMesh::calculateBoundingBox(
 		const std::vector<core::matrix4> &global_transforms)
 {
-	assert(global_transforms.size() == AllJoints.size());
+	_IRR_DEBUG_BREAK_IF(global_transforms.size() != AllJoints.size());
 	core::aabbox3df result = StaticPartsBox;
 	// skeletal animation
 	for (u16 i = 0; i < AllJoints.size(); ++i) {
@@ -444,7 +443,7 @@ void SkinnedMesh::topoSortJoints()
 
 	for (u16 i = 0; i < n; ++i) {
 		if (auto pjid = AllJoints[i]->ParentJointID)
-			assert(*pjid < i);
+			_IRR_DEBUG_BREAK_IF(*pjid >= i);
 	}
 }
 
@@ -518,19 +517,19 @@ SkinnedMesh::SJoint *SkinnedMeshBuilder::addJoint(SJoint *parent)
 
 void SkinnedMeshBuilder::addPositionKey(SJoint *joint, f32 frame, core::vector3df pos)
 {
-	assert(joint);
+	_IRR_DEBUG_BREAK_IF(!joint);
 	joint->keys.position.pushBack(frame, pos);
 }
 
 void SkinnedMeshBuilder::addScaleKey(SJoint *joint, f32 frame, core::vector3df scale)
 {
-	assert(joint);
+	_IRR_DEBUG_BREAK_IF(!joint);
 	joint->keys.scale.pushBack(frame, scale);
 }
 
 void SkinnedMeshBuilder::addRotationKey(SJoint *joint, f32 frame, core::quaternion rot)
 {
-	assert(joint);
+	_IRR_DEBUG_BREAK_IF(!joint);
 	joint->keys.rotation.pushBack(frame, rot);
 }