+
+bool Model::Node::operator==(const Model::Node &rhs) const {
+ return &ai == &rhs.ai;
+}
+
+// Returns closest vertex in world space and distance
+// a and b define the line in 3d space
+Model::VertexLookup Model::closestVertex(Model::Node &n, glm::vec3 a, glm::vec3 b, glm::mat4 parentTrans) const {
+ Model::VertexLookup closest;
+ closest.distance = FLT_MAX;
+
+ for (int i = 0; i < n.ai.mNumMeshes; i++) {
+ int meshIdx = n.ai.mMeshes[i];
+ const aiMesh &mesh = meshes[meshIdx].ai;
+
+ for (int j = 0; j < mesh.mNumVertices; j++) {
+ if (mesh.HasNormals()) {
+ auto n = aiVector3DToVec3(mesh.mNormals[j]);
+ if (glm::dot(n, glm::normalize(b - a)) > 0)
+ continue;
+ }
+ glm::vec4 vPos = glm::vec4(aiVector3DToVec3(mesh.mVertices[j]), 1);
+ // Move from model space -> world space
+ vPos = parentTrans * aiMatrixToMat4(n.ai.mTransformation) * vPos;
+ float dist = glm::distance(glm::vec3(vPos),
+ glm::closestPointOnLine(glm::vec3(vPos), a, b));
+ if (dist < closest.distance) {
+ closest.pos = glm::vec3(vPos);
+ closest.distance = dist;
+ closest.meshIdx = i;
+ closest.vertIdx = j;
+ }
+ }
+ }
+
+ for (auto child: n.getChildren()) {
+ auto childRes = closestVertex(*child, a, b, parentTrans * aiMatrixToMat4(n.ai.mTransformation));
+ if (childRes.distance < closest.distance)
+ closest = childRes;
+ }
+
+ return closest;
+}