From: Luke Lau <luke_lau@icloud.com>
Date: Mon, 17 Feb 2020 01:26:52 +0000 (+0000)
Subject: Some tidying up
X-Git-Tag: cs7gv5-a2~1
X-Git-Url: http://git.lukelau.me/?p=opengl.git;a=commitdiff_plain;h=671418e7effc7cbbb7e05df216291406d2b82dd7

Some tidying up
---

diff --git a/ik.cpp b/ik.cpp
index c6fa603..3895efe 100644
--- a/ik.cpp
+++ b/ik.cpp
@@ -118,83 +118,51 @@ void inverseKinematic(Model::Node &start, Model::Node &end, vec3 target) {
 
 	auto newPositions = fabrik(target, positions, distances);
 
-	// Rotate all the nodes so that they are in the correct positions
+
+	
+	// Move all the nodes so that they are in the correct positions
 	// Don't need to move the root node - it's already in place
 	for (size_t i = 1; i < chain.size(); i++) {
 		auto node = chain[i];
 		mat4 absTrans = getAbsTrans(root, node);
 		absTrans[3] = vec4(newPositions[i], absTrans[3][3]); // update position in transform
 
-		vec3 oldRelPos = extractPos(aiMatrixToMat4(node.ai.mTransformation));
-		vec3 newRelPos = extractPos(absoluteToModelSpace(root, *node.parent, absTrans));
-
-		mat4 rot = getRotationToPoint(oldRelPos, newRelPos, distances[i - 1]);
-		node.ai.mTransformation = mat4ToaiMatrix(rot * aiMatrixToMat4(node.ai.mTransformation));
+		/* vec3 oldRelPos = extractPos(aiMatrixToMat4(node.ai.mTransformation)); */
+		/* vec3 newRelPos = extractPos(absoluteToModelSpace(root, *node.parent, absTrans)); */
+		/* mat4 rot = getRotationToPoint(oldRelPos, newRelPos, distances[i - 1]); */
+		/* node.ai.mTransformation = mat4ToaiMatrix(rot * aiMatrixToMat4(node.ai.mTransformation)); */
 
-		/* std::cerr << node.ai.mName.C_Str() << ":\n"; */
-		/* printVec3(extractPos(aiMatrixToMat4(node.ai.mTransformation))); */
-		/* printVec3(newRelPos); */
-		/* assert(distance(extractPos(aiMatrixToMat4(node.ai.mTransformation)), newRelPos) < 0.0001); */
-
-		/* absTrans[3] = vec4(newPositions[i], absTrans[3][3]); // update position in transform */
+		absTrans[3] = vec4(newPositions[i], absTrans[3][3]); // update position in transform
 		
-		/* mat4 relTrans = absoluteToModelSpace(root, *node.parent, absTrans); */
-		/* node.ai.mTransformation = mat4ToaiMatrix(relTrans); */
+		mat4 relTrans = absoluteToModelSpace(root, *node.parent, absTrans);
+		node.ai.mTransformation = mat4ToaiMatrix(relTrans);
 	}
 
-	// TODO: Now rotate all the nodes so that they point towards each other
+	// Now rotate all the nodes so that they point towards each other
 	// Don't need to rotate the last node - it has nothing to point towards
+	// FIXME: This is numerically unstable and the transformation scales over time!!!
 	for (size_t i = 0; i < chain.size() - 1; i++) {
 		auto node = chain[i]; auto nextNode = chain[i + 1];
 		mat4 oldTrans = aiMatrixToMat4(node.ai.mTransformation);
-		vec3 nodePos = extractPos(oldTrans);
 		vec3 nextNodePos = extractPos(aiMatrixToMat4(nextNode.ai.mTransformation));
 
 
-		/* vec3 up = normalize(oldTrans[1]); */
 		vec3 up = {0, 1, 0};
 		vec3 dir = -normalize(nextNodePos);
-		/* mat4 rot = mat3(aiMatrixToMat4(nextNode.ai.mTransformation)); */
-		/* mat4 rot = transpose(lookAt(vec3(0), dir, {0, 1, 0})); */
 
 		vec3 v = cross(up, dir);
 		mat3 sscpm = mat3(0, -v[2], v[1],
 						  v[2], 0, -v[0],
 						  -v[1], v[0], 0);
 		mat4 rot = mat3(1) + sscpm + sscpm * sscpm * (1.f / 1.f + dot(up, dir));
-		/* mat4 rot = rotate(mat4(1), 0.01f, {0, 1, 0}); */
-		/* mat4 rot = mat4(1); */
 
 
-		mat4 trans = oldTrans * rot * inverse(oldTrans);
-		node.ai.mTransformation = mat4ToaiMatrix(trans * oldTrans);
+		node.ai.mTransformation = mat4ToaiMatrix(oldTrans * rot);
+
 		for (auto child: node.getChildren()) {
 			child->ai.mTransformation = mat4ToaiMatrix(inverse(rot) * aiMatrixToMat4(child->ai.mTransformation));
 		}
 
-		
-		/* vec3 nextNodePos = extractPos(oldTrans * aiMatrixToMat4(nextNode.ai.mTransformation)); */
-		/* vec3 d = normalize(nextNodePos - nodePos); */
-
-		/* mat4 m = mat3(d.z, 0, -d.x, 0, 1, 0, d.x, 0, d.z); */
-
-		/* vec3 up = oldTrans[1]; */
-		/* mat4 look = lookAt(vec3(0), nextNodePos, up); */
-		/* look = oldTrans * look * inverse(oldTrans); */
-		/* node.ai.mTransformation = mat4ToaiMatrix(m * oldTrans); */
-
-		/* for (auto child: node.getChildren()) { */
-		/* 	child->ai.mTransformation = mat4ToaiMatrix(inverse(m) * aiMatrixToMat4(child->ai.mTransformation)); */
-		/* } */
-
-		/* vec3 pos = extractPos(oldTrans); */
-		/* vec3 up = normalize(translate(oldTrans, -pos)); */
-		/* vec3 up = oldTrans[1]; */
-		/* mat4 rot = lookAt(vec3(0), extractPos(aiMatrixToMat4(nextNode.ai.mTransformation)), up); */
-		/* node.ai.mTransformation = mat4ToaiMatrix(translate(rot * translate(oldTrans, -pos), pos)); */
-		/* for (auto child: node.getChildren()) { */
-		/* 	child->ai.mTransformation = mat4ToaiMatrix(inverse(rot) * aiMatrixToMat4(child->ai.mTransformation)); */
-		/* } */
 	}
 
 }