Ymir Engine

Repository Link: Ymir Engine

Current release version: v0.3 - Shader Pipeline

GitHub page: Ymir Engine Website

Description

Ymir Engine is part of the Game Engines subject, on the third year of the Videogame Design and Development degree, taught at CITM UPC (Terrassa) and supervised by Miquel Suau.

The engine has been made from scratch in C++ using SDL and OpenGL to manage graphics. The main target of the project is to be able to integrate complex systems such as graphics management and game engine architecture in a simple and understandable way for educational purposes.

Ymir Engine Logo

Team Members

Francesc Teruel Rodríguez

• GitHub: francesctr4

Joel Romero Botella

• GitHub: Joeltecke25

Disclaimer

• The Release build may weigh a little (1.707 KB) because of the .fbx stored in the Assets folder (Debug build weighs 6.655 KB).

Instructions

Controls

CAMERA

- While Right Clicking, “WASD” FPS-like movement and free look around.
- Mouse wheel zoom in and out.
- "Alt" + Right Click (Press + Drag) orbits around the object.
- Pressing “F” (or "Alt") focus the camera around the world (0,0,0).
- Mouse Wheel Button + Drag pans around the viewport.
- Holding SHIFT while moving the camera duplicates movement speed.

SCENE

- "C" Clears the scene.
- "LCTRL + S": Save the scene.
- "LCTRL + L": Load the scene.
- Hierarchy: Right click to select GameObject and Right click to delete selected GameObject. 
You can drag the GameObjects to reparent them.
- Inspector: Drag Transform values to modify the mesh (only with shader enabled).
- Drag and Drop: Drag .fbx or .png/.dds (to selected GameObject) directly to scene to load them.
- Time Management: Manipulate simulation state with the buttons at the top.
- Assets/Library Window: Left click on the files that are highlighted to open them.
- Mouse Picking: Left Click on a GameObject in the scene to select it.
- Gizmo: Manipulate GameObjects transformation directly from the scene. The controls are: 
    "W" Translation
    "E" Rotation
    "R" Scale
    "O" World
    "L" Local

EDITOR

- File menu: Exit button to shut the engine.
- GameObject menu: Create Empty and Primitives GameObjects and Clear Scene.
- Windows menu: Application menu with general configurations of the engine and several editor 
windows with utilities.
- Help menu: About Modal Window with info of the engine and Repository link.

Additional Instructions

• The Resource Manager is not finished, although you can find the source files in progress (Resources classes and Importers). This means that all the loading of the meshes is being done by Assimp using the Assets file (it will take some time to start the engine).

• The Scene Loading and Saving currently only loads and saves the GameObject structure of the scene and the editor camera position.

• Temporal folder library creation is done correctly and the resources are saved with the custom file format, but they are not being loaded from Library yet.

• It is recommended that you check the Website of the engine in order to know more about the engine features, specially if you want to know everything about the Shader Pipeline and shader management inside the engine.

Features

v0.3 - Shader Pipeline

• The engine uses a shader pipeline to draw geometry.
• Shader Editor: open your shaders or create new ones on runtime with a text editor.
• Shader Hot Reload: Editing a shader in-engine automatically compiles and applies the changes.
• Shader compile error lines and messages are shown in the editor (Console Window).
• Dynamic Shader Uniform Detection & Modification: uniform values are dynamically read from the shader and can be edited from the inspector.
• The shader editor is actually functional and can be used to create shaders and test them on runtime.
• New shaders can be applied to materials with the editor.
• Engine keeps track of loaded shaders to change between them when necessary on gameobjects materials.
• Ymir Engine's default shader ("MyShader.glsl") is applied on GameObjects that don't have any texture or any specific shader attached.
• Water Shader: Flat mesh (plane) that should simulate simple water.
  • Vertex Shader: Simple wave movement.
  • Fragment Shader: The color of the pixels changes based on its height (blue on the bottom, white on the top).

Additional functionality (Cool features!)

• Apart from the water shader, there are more shaders included (all of them created and tested on the engine itself):

Lava Shader

Rainbow Shader

Color Shader

v0.2 - Engine Editor

• The ‘Street Environment’ scene is automatically loaded at the start.
• The user is be able to use the inspector to modify a GameObject:
  • Hierarchy: delete, reparent, create empty and create children.
  • Transform: translate, rotate and scale GameObjects.
  • Camera is a component with settings that can be modified.
• GameObjects can be picked from the world using the mouse.
• All meshes use a bounding volume (AABB) and can be discarded using Frustum Culling.
• Models, meshes and textures are saved to Ymir Engine format under “Library” folder.
• Scene is serialized to a file that can be loaded.
• The user can Start / Pause / Stop the simulation and recover its original state.
• The editor has 2 windows:
  • One with the scene (Editor view).
  • Another one captured from a GameObject with a camera component (Main Game Camera).
  • Each one has its own framebuffer and the user can visualize both at the same time.
• Resource Management:
  • Assets Window that shows all user assets.
  • The user can drop/import new files. Assets window reacts properly.
  • On first use, the temporal folder Library is created and meta files are generated for each new imported asset.
  • Library can be regenerated if deleted.
  • The imported assets are saved in Library folder with Ymir Engine custom file format.

Additional functionality (Cool features!)

• There is a space skybox by default. In the folder Assets/Skybox there is more skybox textures in case you want to test several environments.
• The Assets and Library Windows have some files highlighted on blue, you can interact with them to read the contents inside the engine.
• When you select a GameObject, the shader makes an orange highlight to the mesh.
• There is an option in Inspector -> Mesh Component to turn on/off the Normal Map of the selected Mesh (done by shader).
• The Gizmo has been implemented and can be used to manage GameObjects' transformations.
• The shaders now can be loaded using a single file instead of separating Vertex Shader and Fragment Shader.
• Added Node Editor for future material editing with shaders.

Frustum Culling

Gizmo Showcase

Node Editor

Known bugs (Work in progress)

• There's some visual errors on the material component of the GameObjects in the inspector. When you upload a new model, the texture displayed from the older loaded meshes turns pitch black.

• The vertex normals and the face normals do not follow exactly the GameObject transformations.

• The Gizmo is only usable with meshes with a shader and is visible above the editor.

• Mouse picking can only be done with real transformations, not the ones in the shader. So when you move the GameObject with the gizmo, you can't no longer mouse pick the GameObject.

• Custom File Format files .ymesh and .yscene are being duplicated everytime the engine starts, because it generates a new UID automatically, but .ymodel files and .dds textures are managed correctly.

• When deleting a GameObject sometimes the shader disables and everything is displayed white.

• GameObjects transform has several issues: only applicable to meshes, and models movement doesn't transform correctly the childrens because there is no local transform.

• There's also some visual errors on the transform component of the GameObjects in the inspector. When a model has several meshes and you select the model itself, there is n transform components according to n meshes the model has and the Reset Transform button doesn't work properly in this situation.

v0.1 - Geometry Viewer

• Baker House automatically loaded at the start.
• Two models provided in FBX format with one channel diffuse texture.
• Drag&Drop of FBX files from anywhere in the Hard Drive.
• Drag&Drop of DDS/PNG files (apply the texture to the selected GameObject).
• GameObject structure, one for each loaded mesh.
• Three components available for the GameObjects: Transform, Mesh and Material.
• Unity-like camera controls.
• Editor Windows:
  • Console: Show LOGs.
  • Configuration:
    • A graph for the frames per second.
    • Configuration for variables on each module (renderer, window, input, textures).
    • Information output of memory consumption and hardware detection.
    • OpenGL configuration.
    • ...and more!
  • Hierarchy: list with all GameObjects with tree structure. The user is able to select a GameObject through this window.
  • Inspector: displays information about the components of the selected GameObject.
• About Modal Window to get info about the engine.
• Menu to load basic shapes.

Additional functionality (Cool features!)

• Early Shader Implementation for Rendering Geometry with VAO (Vertex Shader and Fragment Shader).
• Apply Transformations to Geometry with the Transform Component (Translation, Rotation and Scale).
• Custom Icon Uploaded to the Engine Executable.
• Extensive primitive library inside the engine on GameObject menu.

Known bugs (Work in progress)

• There's some visual errors when deleting GameObjects from the hierarchy. The selected GameObject and his children are deleted, but the text of the parent is still displayed as if the GameObject was still there (but it isn't). It is recommended to clear the scene pressing "C" to get rid of the corrupted GameObjects that may appear.

• There's some visual errors on the material component of the GameObjects in the inspector. When you upload a new model, the texture displayed from the older loaded meshes turns pitch black.

• There's also some visual errors on the transform component of the GameObjects in the inspector. When a model has several meshes and you select the model itself, there is n transform components according to n meshes the model has and the Reset Transform button doesn't work properly in this situation. Regardless of the visual error, if you manipulate the first transform you will have the same effect as having the parent transform matrix and the children will transform too.