Add model and include files for Ankit's Skeletal Animation tutorial.

includes/learnopengl/animation.h

@@ -0,0 +1,110 @@
+#pragma once
+
+#include <vector>
+#include <map>
+#include <glm/glm.hpp>
+#include <assimp/scene.h>
+#include <learnopengl/bone.h>
+#include <functional>
+#include <learnopengl/animdata.h>
+#include <learnopengl/model.h>
+
+struct AssimpNodeData
+{
+	glm::mat4 transformation;
+	std::string name;
+	int childrenCount;
+	std::vector<AssimpNodeData> children;
+};
+
+class Animation
+{
+public:
+	Animation() = default;
+
+	Animation(const std::string& animationPath, Model* model)
+	{
+		Assimp::Importer importer;
+		const aiScene* scene = importer.ReadFile(animationPath, aiProcess_Triangulate);
+		assert(scene && scene->mRootNode);
+		auto animation = scene->mAnimations[0];
+		m_Duration = animation->mDuration;
+		m_TicksPerSecond = animation->mTicksPerSecond;
+		aiMatrix4x4 globalTransformation = scene->mRootNode->mTransformation;
+		globalTransformation = globalTransformation.Inverse();
+		ReadHeirarchyData(m_RootNode, scene->mRootNode);
+		SetupBones(animation, *model);
+	}
+
+	~Animation()
+	{
+	}
+
+	Bone* FindBone(const std::string& name)
+	{
+		auto iter = std::find_if(m_Bones.begin(), m_Bones.end(),
+			[&](const Bone& Bone)
+			{
+				return Bone.GetBoneName() == name;
+			}
+		);
+		if (iter == m_Bones.end()) return nullptr;
+		else return &(*iter);
+	}
+
+	
+	inline float GetTicksPerSecond() { return m_TicksPerSecond; }
+	inline float GetDuration() { return m_Duration;}
+	inline const AssimpNodeData& GetRootNode() { return m_RootNode; }
+	inline const std::map<std::string,BoneInfo>& GetBoneIDMap() 
+	{ 
+		return m_BoneInfoMap;
+	}
+
+private:
+	void SetupBones(const aiAnimation* animation, Model& model)
+	{
+		int size = animation->mNumChannels;
+
+		auto& boneInfoMap = model.GetOffsetMatMap();
+		int& boneCount = model.GetBoneCount();
+
+		for (int i = 0; i < size; i++)
+		{
+			auto channel = animation->mChannels[i];
+			std::string boneName = channel->mNodeName.data;
+
+			if (boneInfoMap.find(boneName) == boneInfoMap.end())
+			{
+				boneInfoMap[boneName].id = boneCount;
+				boneCount++;
+			}
+			m_Bones.push_back(Bone(channel->mNodeName.data,
+				boneInfoMap[channel->mNodeName.data].id, channel));
+		}
+
+		m_BoneInfoMap = boneInfoMap;
+	}
+
+	void ReadHeirarchyData(AssimpNodeData& dest, const aiNode* src)
+	{
+		assert(src);
+
+		dest.name = src->mName.data;
+		dest.transformation = AssimpGLMHelpers::ConvertMatrixToGLMFormat(src->mTransformation);
+		dest.childrenCount = src->mNumChildren;
+
+		for (int i = 0; i < src->mNumChildren; i++)
+		{
+			AssimpNodeData newData;
+			ReadHeirarchyData(newData, src->mChildren[i]);
+			dest.children.push_back(newData);
+		}
+	}
+	float m_Duration;
+	int m_TicksPerSecond;
+	std::vector<Bone> m_Bones;
+	AssimpNodeData m_RootNode;
+	std::map<std::string, BoneInfo> m_BoneInfoMap;
+};
+

includes/learnopengl/animator.h

@@ -0,0 +1,78 @@
+#pragma once
+
+#include <glm/glm.hpp>
+#include <map>
+#include <vector>
+#include <assimp/scene.h>
+#include <assimp/Importer.hpp>
+#include <learnopengl/animation.h>
+#include <learnopengl/bone.h>
+
+class Animator
+{	
+public:
+	Animator::Animator(Animation* current)
+	{
+		m_CurrentAnimation = current;
+		m_CurrentTime = 0.0;
+		m_Transforms.reserve(100);
+		for (int i = 0; i < 100; i++)
+			m_Transforms.push_back(glm::mat4(1.0f));
+	}
+
+	void Animator::UpdateAnimation(float dt)
+	{
+		m_DeltaTime = dt;
+		if (m_CurrentAnimation)
+		{
+			m_CurrentTime += m_CurrentAnimation->GetTicksPerSecond() * dt;
+			m_CurrentTime = fmod(m_CurrentTime, m_CurrentAnimation->GetDuration());
+			CalculateBoneTransform(&m_CurrentAnimation->GetRootNode(), glm::mat4(1.0f));
+		}
+	}
+
+	void Animator::PlayAnimation(Animation* pAnimation)
+	{
+		m_CurrentAnimation = pAnimation;
+		m_CurrentTime = 0.0f;
+	}
+
+	void Animator::CalculateBoneTransform(const AssimpNodeData* node, glm::mat4 parentTransform)
+	{
+		std::string nodeName = node->name;
+		glm::mat4 nodeTransform = node->transformation;
+
+		Bone* Bone = m_CurrentAnimation->FindBone(nodeName);
+
+		if (Bone)
+		{
+			Bone->Update(m_CurrentTime);
+			nodeTransform = Bone->GetLocalTransform();
+		}
+
+		glm::mat4 globalTransformation = parentTransform * nodeTransform;
+
+		auto boneInfoMap = m_CurrentAnimation->GetBoneIDMap();
+		if (boneInfoMap.find(nodeName) != boneInfoMap.end())
+		{
+			int index = boneInfoMap[nodeName].id;
+			glm::mat4 offset = boneInfoMap[nodeName].offset;
+			m_Transforms[index] = globalTransformation * offset;
+		}
+
+		for (int i = 0; i < node->childrenCount; i++)
+			CalculateBoneTransform(&node->children[i], globalTransformation);
+	}
+
+	std::vector<glm::mat4> GetPoseTransforms() 
+	{ 
+		return m_Transforms;  
+	}
+	
+private:
+	std::vector<glm::mat4> m_Transforms;
+	Animation* m_CurrentAnimation;
+	float m_CurrentTime;
+	float m_DeltaTime;
+	
+};

includes/learnopengl/animdata.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <glm/glm.hpp>
+
+struct BoneInfo
+{
+	/*
+		For uniquely indentifying the bone and
+		for indexing bone transformation in shaders
+	*/
+	int id;
+	/*
+		map from bone name to offset matrix.
+		offset matrix transforms bone from bone space to local space
+	*/
+	glm::mat4 offset;
+
+};
+#pragma once

includes/learnopengl/bone.h

@@ -0,0 +1,188 @@
+#pragma once
+
+/* Container for bone data */
+
+#include <vector>
+#include <assimp/scene.h>
+#include <list>
+#include <glm/glm.hpp>
+#define GLM_ENABLE_EXPERIMENTAL
+#include <glm/gtx/quaternion.hpp>
+#include "AssimpGLMHelpers.h"
+
+struct KeyPosition
+{
+	glm::vec3 position;
+	float timeStamp;
+};
+
+struct KeyRotation
+{
+	glm::quat orientation;
+	float timeStamp;
+};
+
+struct KeyScale
+{
+	glm::vec3 scale;
+	float timeStamp;
+};
+
+class Bone
+{
+public:
+	Bone(const std::string& name, int ID, const aiNodeAnim* channel)
+		:
+		m_Name(name),
+		m_ID(ID),
+		m_LocalTransform(1.0f)
+	{
+		m_NumPositions = channel->mNumPositionKeys;
+
+		for (int positionIndex = 0; positionIndex < m_NumPositions; ++positionIndex)
+		{
+			aiVector3D aiPosition = channel->mPositionKeys[positionIndex].mValue;
+			float timeStamp = channel->mPositionKeys[positionIndex].mTime;
+			KeyPosition data;
+			data.position = AssimpGLMHelpers::GetGLMVec(aiPosition);
+			data.timeStamp = timeStamp;
+			m_Positions.push_back(data);
+		}
+
+		m_NumRotations = channel->mNumRotationKeys;
+		for (int rotationIndex = 0; rotationIndex < m_NumRotations; ++rotationIndex)
+		{
+			aiQuaternion aiOrientation = channel->mRotationKeys[rotationIndex].mValue;
+			float timeStamp = channel->mRotationKeys[rotationIndex].mTime;
+			KeyRotation data;
+			data.orientation = AssimpGLMHelpers::GetGLMQuat(aiOrientation);
+			data.timeStamp = timeStamp;
+			m_Rotations.push_back(data);
+		}
+
+		m_NumScalings = channel->mNumScalingKeys;
+		for (int keyIndex = 0; keyIndex < m_NumScalings; ++keyIndex)
+		{
+			aiVector3D scale = channel->mScalingKeys[keyIndex].mValue;
+			float timeStamp = channel->mScalingKeys[keyIndex].mTime;
+			KeyScale data;
+			data.scale = AssimpGLMHelpers::GetGLMVec(scale);
+			data.timeStamp = timeStamp;
+			m_Scales.push_back(data);
+		}
+	}
+	
+	void Update(float animationTime)
+	{
+		glm::mat4 translation = InterpolatePosition(animationTime);
+		glm::mat4 rotation = InterpolateRotation(animationTime);
+		glm::mat4 scale = InterpolateScaling(animationTime);
+		m_LocalTransform = translation * rotation * scale;
+	}
+	glm::mat4 GetLocalTransform() { return m_LocalTransform; }
+	std::string GetBoneName() const { return m_Name; }
+	int GetBoneID() { return m_ID; }
+	
+
+
+	int GetPositionIndex(float animationTime)
+	{
+		for (int index = 0; index < m_NumPositions - 1; ++index)
+		{
+			if (animationTime < m_Positions[index + 1].timeStamp)
+				return index;
+		}
+		assert(0);
+	}
+
+	int GetRotationIndex(float animationTime)
+	{
+		for (int index = 0; index < m_NumRotations - 1; ++index)
+		{
+			if (animationTime < m_Rotations[index + 1].timeStamp)
+				return index;
+		}
+		assert(0);
+	}
+
+	int GetScaleIndex(float animationTime)
+	{
+		for (int index = 0; index < m_NumScalings - 1; ++index)
+		{
+			if (animationTime < m_Scales[index + 1].timeStamp)
+				return index;
+		}
+		assert(0);
+	}
+
+
+private:
+
+	float GetScaleFactor(float lastTimeStamp, float nextTimeStamp, float animationTime)
+	{
+		float scaleFactor = 0.0f;
+		float midWayLength = animationTime - lastTimeStamp;
+		float framesDiff = nextTimeStamp - lastTimeStamp;
+		scaleFactor = midWayLength / framesDiff;
+		return scaleFactor;
+	}
+
+	glm::mat4 InterpolatePosition(float animationTime)
+	{
+		if (1 == m_NumPositions)
+			return glm::translate(glm::mat4(1.0f), m_Positions[0].position);
+
+		int p0Index = GetPositionIndex(animationTime);
+		int p1Index = p0Index + 1;
+		float scaleFactor = GetScaleFactor(m_Positions[p0Index].timeStamp,
+			m_Positions[p1Index].timeStamp, animationTime);
+		glm::vec3 finalPosition = glm::mix(m_Positions[p0Index].position, m_Positions[p1Index].position
+			, scaleFactor);
+		return glm::translate(glm::mat4(1.0f), finalPosition);
+	}
+
+	glm::mat4 InterpolateRotation(float animationTime)
+	{
+		if (1 == m_NumRotations)
+		{
+			auto rotation = glm::normalize(m_Rotations[0].orientation);
+			return glm::toMat4(rotation);
+		}
+
+		int p0Index = GetRotationIndex(animationTime);
+		int p1Index = p0Index + 1;
+		float scaleFactor = GetScaleFactor(m_Rotations[p0Index].timeStamp,
+			m_Rotations[p1Index].timeStamp, animationTime);
+		glm::quat finalRotation = glm::slerp(m_Rotations[p0Index].orientation, m_Rotations[p1Index].orientation
+			, scaleFactor);
+		finalRotation = glm::normalize(finalRotation);
+		return glm::toMat4(finalRotation);
+
+	}
+
+	glm::mat4 Bone::InterpolateScaling(float animationTime)
+	{
+		if (1 == m_NumScalings)
+			return glm::scale(glm::mat4(1.0f), m_Scales[0].scale);
+
+		int p0Index = GetScaleIndex(animationTime);
+		int p1Index = p0Index + 1;
+		float scaleFactor = GetScaleFactor(m_Scales[p0Index].timeStamp,
+			m_Scales[p1Index].timeStamp, animationTime);
+		glm::vec3 finalScale = glm::mix(m_Scales[p0Index].scale, m_Scales[p1Index].scale
+			, scaleFactor);
+		return glm::scale(glm::mat4(1.0f), finalScale);
+	}
+
+	std::vector<KeyPosition> m_Positions;
+	std::vector<KeyRotation> m_Rotations;
+	std::vector<KeyScale> m_Scales;
+	int m_NumPositions;
+	int m_NumRotations;
+	int m_NumScalings;
+
+	glm::mat4 m_LocalTransform;
+	std::string m_Name;
+	int m_ID;
+};
+

includes/learnopengl/model_animation.h

@@ -0,0 +1,282 @@
+#ifndef MODEL_H
+#define MODEL_H
+
+#include <glad/glad.h> 
+
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <stb_image.h>
+#include <assimp/Importer.hpp>
+#include <assimp/scene.h>
+#include <assimp/postprocess.h>
+
+#include <learnopengl/mesh.h>
+#include <learnopengl/shader.h>
+
+#include <string>
+#include <fstream>
+#include <sstream>
+#include <iostream>
+#include <map>
+#include <vector>
+#include <learnopengl/assimp_glm_helpers.h>
+#include <learnopengl/animdata.h>
+
+using namespace std;
+
+class Model 
+{
+public:
+    // model data 
+    vector<Texture> textures_loaded;	// stores all the textures loaded so far, optimization to make sure textures aren't loaded more than once.
+    vector<Mesh>    meshes;
+    string directory;
+    bool gammaCorrection;
+	
+	
+
+    // constructor, expects a filepath to a 3D model.
+    Model(string const &path, bool gamma = false) : gammaCorrection(gamma)
+    {
+        loadModel(path);
+    }
+
+    // draws the model, and thus all its meshes
+    void Draw(Shader &shader)
+    {
+        for(unsigned int i = 0; i < meshes.size(); i++)
+            meshes[i].Draw(shader);
+    }
+    
+	auto& GetOffsetMatMap() { return m_OffsetMatMap; }
+	int& GetBoneCount() { return m_BoneCount; }
+	
+
+private:
+
+	std::map<string, BoneInfo> m_OffsetMatMap;
+	int m_BoneCount = 0;
+
+    // loads a model with supported ASSIMP extensions from file and stores the resulting meshes in the meshes vector.
+    void loadModel(string const &path)
+    {
+        // read file via ASSIMP
+        Assimp::Importer importer;
+        const aiScene* scene = importer.ReadFile(path, aiProcess_Triangulate | aiProcess_GenSmoothNormals | aiProcess_CalcTangentSpace);
+        // check for errors
+        if(!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) // if is Not Zero
+        {
+            cout << "ERROR::ASSIMP:: " << importer.GetErrorString() << endl;
+            return;
+        }
+        // retrieve the directory path of the filepath
+        directory = path.substr(0, path.find_last_of('/'));
+
+        // process ASSIMP's root node recursively
+        processNode(scene->mRootNode, scene);
+    }
+
+    // processes a node in a recursive fashion. Processes each individual mesh located at the node and repeats this process on its children nodes (if any).
+    void processNode(aiNode *node, const aiScene *scene)
+    {
+        // process each mesh located at the current node
+        for(unsigned int i = 0; i < node->mNumMeshes; i++)
+        {
+            // the node object only contains indices to index the actual objects in the scene. 
+            // the scene contains all the data, node is just to keep stuff organized (like relations between nodes).
+            aiMesh* mesh = scene->mMeshes[node->mMeshes[i]];
+            meshes.push_back(processMesh(mesh, scene));
+        }
+        // after we've processed all of the meshes (if any) we then recursively process each of the children nodes
+        for(unsigned int i = 0; i < node->mNumChildren; i++)
+        {
+            processNode(node->mChildren[i], scene);
+        }
+
+    }
+
+	void SetVertexBoneDataToDefault(Vertex& vertex)
+	{
+		for (int i = 0; i < MAX_BONE_WEIGHTS; i++)
+		{
+			vertex.m_BoneIDs[i] = -1;
+			vertex.m_Weights[i] = 0.0f;
+		}
+	}
+
+
+	Mesh processMesh(aiMesh* mesh, const aiScene* scene)
+	{
+		vector<Vertex> vertices;
+		vector<unsigned int> indices;
+		vector<Texture> textures;
+
+		for (unsigned int i = 0; i < mesh->mNumVertices; i++)
+		{
+			Vertex vertex;
+			SetVertexBoneDataToDefault(vertex);
+			vertex.Position = AssimpGLMHelpers::GetGLMVec(mesh->mVertices[i]);
+			vertex.Normal = AssimpGLMHelpers::GetGLMVec(mesh->mNormals[i]);
+			
+			if (mesh->mTextureCoords[0])
+			{
+				glm::vec2 vec;
+				vec.x = mesh->mTextureCoords[0][i].x;
+				vec.y = mesh->mTextureCoords[0][i].y;
+				vertex.TexCoords = vec;
+			}
+			else
+				vertex.TexCoords = glm::vec2(0.0f, 0.0f);
+
+			vertices.push_back(vertex);
+		}
+		for (unsigned int i = 0; i < mesh->mNumFaces; i++)
+		{
+			aiFace face = mesh->mFaces[i];
+			for (unsigned int j = 0; j < face.mNumIndices; j++)
+				indices.push_back(face.mIndices[j]);
+		}
+		aiMaterial* material = scene->mMaterials[mesh->mMaterialIndex];
+
+		vector<Texture> diffuseMaps = loadMaterialTextures(material, aiTextureType_DIFFUSE, "texture_diffuse");
+		textures.insert(textures.end(), diffuseMaps.begin(), diffuseMaps.end());
+		vector<Texture> specularMaps = loadMaterialTextures(material, aiTextureType_SPECULAR, "texture_specular");
+		textures.insert(textures.end(), specularMaps.begin(), specularMaps.end());
+		std::vector<Texture> normalMaps = loadMaterialTextures(material, aiTextureType_HEIGHT, "texture_normal");
+		textures.insert(textures.end(), normalMaps.begin(), normalMaps.end());
+		std::vector<Texture> heightMaps = loadMaterialTextures(material, aiTextureType_AMBIENT, "texture_height");
+		textures.insert(textures.end(), heightMaps.begin(), heightMaps.end());
+
+		ExtractBoneWeightForVertices(vertices,mesh,scene);
+
+		return Mesh(vertices, indices, textures);
+	}
+
+	void SetVertexBoneData(Vertex& vertex, int boneID, float weight)
+	{
+		for (int i = 0; i < MAX_BONE_WEIGHTS; ++i)
+		{
+			if (vertex.m_BoneIDs[i] < 0)
+			{
+				vertex.m_Weights[i] = weight;
+				vertex.m_BoneIDs[i] = boneID;
+				break;
+			}
+		}
+	}
+
+
+	void ExtractBoneWeightForVertices(std::vector<Vertex>& vertices, aiMesh* mesh, const aiScene* scene)
+	{
+		auto& boneInfoMap = m_OffsetMatMap;
+		int& boneCount = m_BoneCount;
+
+		for (int boneIndex = 0; boneIndex < mesh->mNumBones; ++boneIndex)
+		{
+			int boneID = -1;
+			std::string boneName = mesh->mBones[boneIndex]->mName.C_Str();
+			if (boneInfoMap.find(boneName) == boneInfoMap.end())
+			{
+				BoneInfo newBoneInfo;
+				newBoneInfo.id = boneCount;
+				newBoneInfo.offset = AssimpGLMHelpers::ConvertMatrixToGLMFormat(mesh->mBones[boneIndex]->mOffsetMatrix);
+				boneInfoMap[boneName] = newBoneInfo;
+				boneID = boneCount;
+				boneCount++;
+			}
+			else
+			{
+				boneID = boneInfoMap[boneName].id;
+			}
+			assert(boneID != -1);
+			auto weights = mesh->mBones[boneIndex]->mWeights;
+			int numWeights = mesh->mBones[boneIndex]->mNumWeights;
+
+			for (int weightIndex = 0; weightIndex < numWeights; ++weightIndex)
+			{
+				int vertexId = weights[weightIndex].mVertexId;
+				float weight = weights[weightIndex].mWeight;
+				assert(vertexId <= vertices.size());
+				SetVertexBoneData(vertices[vertexId], boneID, weight);
+			}
+		}
+	}
+
+
+	unsigned int TextureFromFile(const char* path, const string& directory, bool gamma = false)
+	{
+		string filename = string(path);
+		filename = directory + '/' + filename;
+
+		unsigned int textureID;
+		glGenTextures(1, &textureID);
+
+		int width, height, nrComponents;
+		unsigned char* data = stbi_load(filename.c_str(), &width, &height, &nrComponents, 0);
+		if (data)
+		{
+			GLenum format;
+			if (nrComponents == 1)
+				format = GL_RED;
+			else if (nrComponents == 3)
+				format = GL_RGB;
+			else if (nrComponents == 4)
+				format = GL_RGBA;
+
+			glBindTexture(GL_TEXTURE_2D, textureID);
+			glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+			glGenerateMipmap(GL_TEXTURE_2D);
+
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+			stbi_image_free(data);
+		}
+		else
+		{
+			std::cout << "Texture failed to load at path: " << path << std::endl;
+			stbi_image_free(data);
+		}
+
+		return textureID;
+	}
+    
+    // checks all material textures of a given type and loads the textures if they're not loaded yet.
+    // the required info is returned as a Texture struct.
+    vector<Texture> loadMaterialTextures(aiMaterial *mat, aiTextureType type, string typeName)
+    {
+        vector<Texture> textures;
+        for(unsigned int i = 0; i < mat->GetTextureCount(type); i++)
+        {
+            aiString str;
+            mat->GetTexture(type, i, &str);
+            // check if texture was loaded before and if so, continue to next iteration: skip loading a new texture
+            bool skip = false;
+            for(unsigned int j = 0; j < textures_loaded.size(); j++)
+            {
+                if(std::strcmp(textures_loaded[j].path.data(), str.C_Str()) == 0)
+                {
+                    textures.push_back(textures_loaded[j]);
+                    skip = true; // a texture with the same filepath has already been loaded, continue to next one. (optimization)
+                    break;
+                }
+            }
+            if(!skip)
+            {   // if texture hasn't been loaded already, load it
+                Texture texture;
+                texture.id = TextureFromFile(str.C_Str(), this->directory);
+                texture.type = typeName;
+                texture.path = str.C_Str();
+                textures.push_back(texture);
+                textures_loaded.push_back(texture);  // store it as texture loaded for entire model, to ensure we won't unnecesery load duplicate textures.
+            }
+        }
+        return textures;
+    }
+};
+
+
+
+#endif