yaw-central / yaw-engine

A simple 3D engine (LWJGL/Clojure)

Yaw : live-coding a (simple) 3D world

(ultimately) a 3D live-coding experience for Clojurians of all ages

(for now a very basic 3D engine based on LLWJGL with a thin and imperative Clojure wrapper)

Disclaimer

Yaw is not yet usable, except for extremely simplistic examples! The Java/OpenGL-side of things is a basic engine relatively well-tested. The Clojure part is minimalistic, a separate projet, yaw-reactive, investigates a more idiomatic way to 3D programming in Clojure.

Requirements

• Clojure 1.8+
• Java : 1.8 +
• Leiningen 2.7.1+
• LWJGL 3.0+ (via Hello_jgl, thanks !)

How to start ?

For now the Clojure API is just a thin layer above the java mess... So expect many bangs (!'s) ...

Most of the current API can be found in the yaw.world namespace.

So you can fire your repl

$ lein repl

and type (after the => prompt of course):

(use 'yaw.world)

An openGL window lives in a world (because we're megalomaniacs!)

(def world (create-world!))

If all goes well a window will open, empty and dark as hell!

Yaw will only use basic 3D objects with simple materials. For new there's only a bunch of available objects, and the material only talks about color and reflectance.

Let's create a solid block (a.k.a. a cube) with the default properties.

(def block (create-block! world))

Now you should see a blue block in the middle of your window. If not, then something went wrong ... please fill an issue in this case (if you're on a mac please stay tuned and blame the company behind it)...

To see something we should put it a little bit farther away.

(translate! block :z -2)

We can rotate our cube, e.g. 20 degrees on y...

(rotate! block :y 20)

It's working (hopefully) but we don't really see the edges of the block. That's because the only light in the scene for now is ambient light.

More shapes

One can also quickly create a square-based pyramid like so

(def pyr (create-pyramid! world))

Summary

(use 'yaw.world)
(def univ (start-universe!))
(def world (:world @univ))
(def block (create-block! world))
(translate! block :z -2)
(rotate! block :y 20)

How to develop ?

This project being a mixed Java/Clojure project, we actively encourage the use of Intellij Idea together with the Cursive plugins for Clojure development.

For now we use the leiningen tool for build management, at some point we will also support the newer Deps.

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Copyright (C) 2016-∞ F. Peschanski et al. under the MIT License

yaw-engine's Issues

Add a visible flag for items

Allow to parameterize the maximum number of lights

The shader code is dependent on the (maximum) number of lights (points, spots), but for now it is a constant in the shader code.
A simpler improvement would be to allow these limits to be fixed at the time of constructing the main shader programs.
Also, unusued light slots should not lead to computations.
More challenging would be to adapt the shader code dynamically when changing the number of lights. This is related to the support of scene install/uninstall

Support for PBR material and lightning

dynamic shader programs

For now the shader code is written as standalone files. A more dynamic approach should be used, for example to allow for a variable number of lights.

Load material from MTL (+ finish OBJ loader)

The OBJ loader is incomplete, the MTL part of the loader must be added

Algorithms for mesh generation

Add mesh generation algorithms:

• basic meshes : planes, cuboids, cones, cylinders, tores, spheres, polyhedrons ...
• curved surfaces
• more advanced meshes (?)

Review and fix of light system

The light system is buggy, and does not support all features of common light properties (cf. MTL material description and issue #16

Combination of drawing strategies

There is a preliminary support for so-called drawing strategies, i.e. different ways of drawing meshes. The system should be put into practice:

1. allowing various strategies : default (using material), gouraud/phong/..., wireframe, and helpers (e.g. normals, ...)
2. allowing to compose drawing strategies

Drawing helpers

Add drawing helpers:

• object helpers : vertices, triangles, normals, (textcoords ?)
• world helpers: origin and X/Y/Z unit vectors, grids for X/Y/Z planes
• camera helpers : position, orientation (front/right/up vectors)

Allow a material per face (at least solid color) instead of whole mesh

Support for Structured/Animated models

Support for model as found in IQM or GLTf3

add a fullscreen mode

Restore Shadow mapping

Shadow mapping is not applied correctly since shader code remodularization.

Support for dynamic scene install/uninstall

For now, only one global scene is supported. The scene components can be added and removed, but we might imagine different scenes with different opengl features, e.g. immediate vs. deferred lightnin or other variations with global impact.