Engine Prototype 01

Full View

This is my first prototype of the Dejeweled physics engine. So far the engine supports simple rod constraints in two flavors: rigid and springy. Next up are pin constraints.

The ragdoll here is a slightly modified version of the one from my earlier Ragdoll Control Prototype, with a new physics engine and some shiny new graphics in the Dejeweled style.

Click the window to start. Then use the arrow keys to move the stick figure around.

left - rotate left
right - rotate right
up - raise arms
down - spread legs

For slow motion, hold down the space bar. Click the meters to adjust the physics settings.

Let me know if you find anything interesting. ;)

Engine Screen 01

Here's a quick screen shot of what I've been working on. I've just refitted my old Ragdoll Control Prototype with a shiny new physics engine, the Dejeweled Engine. So far I've got both rigid and springy rods working, as well as some decent slow motion. Next up are pin constraints, and then collisions.

As you can see in the picture, I've been playing with some graphical effects. There's a white inner glow on the ragdoll body, some glow on the blue lines, and a sort of reflection or shadow below. I'm trying to get it to feel more like a 3D figure in an endless white field, rather than of a 2D bunch of lines on a computer screen. Not sure if any of this will end up in the final game, but for now I'm just playing around. It's fun. :)

Once I add pin constraints and make the physics settings adjustable, I'll release the prototype here.

Inspiration Series 02

In my last post, I mentioned that Dejeweled is about carving out your own reality from a blinding white field of full-spectrum light, all possibilities at once.

This image, from the upcoming LEGO Universe MMO, is a perfect example. These construction workers are not building a universe out of dark nothingness, they are carving a universe out of the infinite potential of the fresh, white page. They are removing, paring down possibilities, until something tangible can remain.


I love this picture.

Inspiration Series 01

Dejeweled is about carving out your own reality from a blinding white field of full-spectrum light, all possibilities at once. That's the feel I want to convey in the art style. You create by subtraction, by taking away, by defining constraints. Like layers of ink on a blank page. The opposite approach would be additive, building up a universe one spark at a time from the cold, infinitely black void, or a cursor blinking on a dark computer screen, waiting for your first command. That's not Dejeweled. Dejeweled is white, bright, light, sliced into actuality.

I originally got this from The Matrix. Here are a few more examples I've found.

Click the images for the full-size originals.

I hope to make Dejeweled feel like this.

Why I Just Do White...
SL Portal Collab Entry
sail to the moon
cyber pepper

Frequently Asked Questions

"Is the game done yet?"

No. When it's done, we'll tell you.

"When will the game be released?"

We don't know yet. We're developing Dejeweled in our meager free time alongside work and school, so it's hard to come up with a definite development schedule. Until we get further along, the best we can say at this point is that it's probably going to take a while. In the meantime, you can subscribe to our blog feed for the latest updates on our progress.

"Will the game be free to play?"

Yes. Dejeweled will be a free Flash game, just like all the other free Flash games on the web. We'll be putting up a donate button once the game is released in case you want to support the project directly. If the opportunity arises, we may also incorporate special game items that you can buy with real money. But we'll see.

Introducing... Dejeweled!

Welcome to the Dejeweled Development Blog! This is where we'll be posting all official information about the upcoming game Dejeweled.

About the Game

Dejeweled will be a Flash game available to play on the web for free. It will be a physics-based building game, where you construct elaborate contraptions in order to brutally extract jewels from the bodies of defenseless ragdolls. Hence the name, Dejeweled.

The business model for funding the project is as of yet undecided. However, it will be definitely be free to play. Most likely, ads will be embedded into the web page the game sits in, or directly into the loading screen through MochiAds. This revenue may be supplemented with non-exclusive licenses to specific game sites such as Miniclip.

About the Team

The current development team consists of axcho (design and coding) and Prospect (design and music).

The idea for the game was first brought forth by Prospect in June of 2007. Since then, the design has slowly solidified with the help of the Stick Page Portal community. Originally we had planned to really get going in 2008, but life happened, and this didn't. Now it's 2009, and we think we might actually have a chance of getting somewhere.

So, as we crank out the concept art and experimental prototypes, we'll be presenting them here, on this blog, for your enjoyment and critique. Stay tuned.

There are currently no estimates as to the completion date of this project. We will see how it evolves. :)

Dejeweled Engine constraint functions

Today I dusted off my calculus hat and got to work on the math behind the Dejeweled physics engine (specifically the projection gradient functions for the constraint solver).

If you're curious, the physics engine I'm working on is based on the approach described in Position Based Dynamics (excellent paper), which provides an algorithm for simulating particle physics with any sort of constraint you can imagine. You just need to do a bit of vector calculus first. :)

Here's what I've come up with: (may contain errors)

Notation Notes!

• Uppercase letters are vectors, lowercase letters are scalars
• | V | = length of vector V
• U . V = dot product of vectors U and V

Rod Constraint (P1, P2, d)
a simple rod of distance d with endpoints P1 and P2

• Constraint function C = | P1 - P2 | - d
• Gradient function P1C = ( P1 - P2 ) / | P1 - P2 |
• Gradient function P2C = ( P2 - P1 ) / | P1 - P2 |

Pin Constraint (P0, P1, P2, f, d)
a connection of distance d between pin P0 and the point Pf at fraction f along the line from point P1 to P2

• Intermediate point Pf = (1-f)P1 + (f)P2
• Constraint function C = | P0 - Pf | - d
• Gradient function P0C = ( P0 - Pf ) / | P0 - Pf |
• Gradient function P1C = (f-1)( P0 - Pf ) / | P0 - Pf |
• Gradient function P2C = (-f)( P0 - Pf ) / | P0 - Pf |

Wall Constraint (P0, P1, N, d)
a separation of distance d between point P0 and the surface of a wall at point P1 with surface normal N

• Constraint function C = ( P0 - Pf ) . N - d
• Gradient function P0C = N
• Gradient function P1C = -N

Door Constraint (P0, P1, P2, d)
a hinge centered on point P0 between endpoints P1 and P2 at an angle corresponding to dot product d

• Constraint function C = ( P0 - P1 ) . ( P0 - P2 ) - d
• Gradient function P0C = ( P0 - P1 ) + ( P0 - P2 )
• Gradient function P1C = ( P2 - P0 )
• Gradient function P2C = ( P1 - P0 )

Those four constraint types should be plenty, at least for now.