3D Pinball Game – Development Project

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This is a 3D pinball game developed as part of my MSc Computer Science. The module was a group project and we were tasked with developing a 3D pinball without using an existing propriety game engine (such as Unity or Unreal etc.).

I developed an easy to use DX11 renderer for use by the group and we incorporated the Bullet physics and FMOD libraries to put the game together.

The time constraints on the project were intense and so this was put together in around 10 days (some crazy hours ensued). Many cans of energy drink and cups of coffee later this was the result. Its not exactly pinball FX but factoring in timeframe and tool constraints, I’m pleased with how it turned out. I wouldn’t expect a public release any time soon though!

Gallery:

Bullet physics is pretty fiddly to get up and running and took a bit of research to get to grips with. As with most open source libraries there are many conflicting sources of documentation and versions floating around which often serve only to confuse, but for a free physics library you can hardly complain.

I worked on quite a bit of the project, putting together the renderer and framework that the group used for production. I programmed the graphics, did any required artwork (base textures were sourced online) and worked a lot on the important physics such as the flippers and launch mechanism. With more time we could have improved quite a bit, as it stands the physics aren’t on a fixed time step and neither is it on an independent thread, therefore bad things happen if the frame rate gets low. For this reason it’s designed to run more or less perfectly on the system we developed it on and we were marked on, but it would need a fair bit of improvement to get it working nicely on any system and I doubt I’ll have time for that any time soon.

The project was probably my first real taste of game dev crunch or ‘death march’. Really it was worse, with 16+ hour days, often leaving the lab after sunrise. In the end, I think it was worth it though and I had actually always quite fancied trying my hand at developing a pinball game!

PS. Thanks to the guys (and gal) for such a hard-working group.

Falling Object Simulator – Simulation & Concurrency

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As part of my MSC Computer Science degree, the Simulation & Concurrency module was probably the most intense module on the course, tasking us to produce a physics engine from scratch with robust network and multi-threading integration in order to implement a simulation of balls falling into a box, with removable trays and also a cloth simulated net.

Having done only a little previous physics programming for ‘The Column’, I set about researching the topic since implementing a solid and robust physics engine is no trivial task, even without a networking element. Although I found several good sources, for specific elements, Ian Millington’s ‘Game Physics Engine Development’ was an excellent book that covered many aspects of getting a basic physics engine up and running. I promptly devoured about a third of the book during this project though it lacks any real depth on collision detection and doesn’t real cover cloth simulation as I recall.

In the end I received 87% for the ACW which I’m pleased with. With more time I would have implemented rigid body motion but this second semester of the MSc has been pretty insane in terms of work load, mainly due to the fact that the UK carries out MSc degrees in a single year, rather then 2 like everywhere else in the world! Additionally, the University of Hull’s MSc degree is extremely practical, which although I find preferable to more theoretical based degrees (how better to learn then via implementation?) does result in a heavy work load. The good side is that if you put the work in, your get an extensive portfolio at the end of the degree.

Project Description:

The result of the project was a multi-threaded interactive falling object simulator developed from scratch using C++ and DirectX 11. The physics engine is a mass aggregate system using particles i.e. no rigid body motion. It features simple sphere and plane based collision detection and interpenetration resolution.

Each tray features different friction and elasticity attributes as per the specification.

An advanced feature is the cloth simulation for the net made using a lattice of spring constraints (Hook’s law) with four anchored corners.

Net collision detection is made using small spheres mapped to the vertices of the net, this however means I had to make the springs quite rigid to stop balls from forcing their way in-between the vertices hence the cloth is not very fluid or fluttery.

Without rigid body dynamics to get the cube rotations I used rod constraints connected to each vertex of the cube. This is a simple way to get rotations using just particles.

Rendering and physics integration are performed on separate threads, with an additional 3 threads for handling network. Rendering frame rate is hence independent from the simulation and both can be changed to run at a specific target rate.

Not shown in the video, but being a significant part of the project is the peer-to-peer network aspect. The program can be run on 2 peers, each peer will communicate and synchronise the simulation using linear interpolation of the scenes physics data. Each peer can be interacted with i.e. camera can be moved independently (think multiplayer) and commands such as open/close tray and spawn ball is communicated across the network to each peer. Network coding was done using Winsock. UDP broadcasting was used purely for peer detection and TCP for data transmission. Packet loss and latency resilience was also implemented.