DigitalRune Blog

Jumping – One Simple Detail That Improves Every Game

Mon, 06 Sep 2010 13:29:00 GMT

Jumping Is Important!

Seriously. If I cannot jump in an action game, chances are high that I will not play it.

Do you remember that there once was a game type called "Jump'n'Run" – where according to the genre name jumping was 50% of the gameplay and the joy? Jumping on its own is fun and it is a natural way to show emotion. In World of Warcraft, for example, jumping is the simplest expression of feelings. – Typing emotes is way to complicated for me ;-)

Implementing Jumping

When implementing jumping an interesting question arises: How much control does the user have while jumping?

3D Programmer's Best Friend

Sat, 28 Aug 2010 09:00:17 GMT

Ok, this one is simple - but simple things matter. Take a block of wood, drill three holes and add 3 colored pencils. If you do it right, you might get something like this:

…

3D Character Controller Implementation

Thu, 26 Aug 2010 15:55:59 GMT

Yet another blog post about character controllers for 3D games, and this time we will talk about the actual implementation.

Kinematic Character Controller Using Discrete Collision Detection

Here is how the character controller in our Character Controller Example works:

Capsule Shape

The character is represented as a an upright capsule that does not rotate:

…

Kinematic vs. Dynamic Character Controllers

Fri, 20 Aug 2010 15:05:35 GMT

There are at least two ways to implement a character controller for a 3D game: Kinematic and Dynamic Character Controllers. In this post we discuss the difference and which solution is better.

A short reminder:
In this context a character controller is the piece of code that computes the movement of the player character in the game. It takes care that the user does not run through walls, can step up/down, jump etc. The character is often modeled as an upright capsule.

Kinematic Character Controller

…

Character Controller Requirements

Tue, 17 Aug 2010 08:44:03 GMT

In one of the last posts we introduced our Character Controller Example. In the next posts, we will discuss character controllers for 3D games in more detail, including: general requirements, kinematic vs. dynamic character controllers, implementation, character controllers in virtual reality.

This post starts the series with a discussion of requirements of 3D game character controller.

Functional Requirements

Teleport

The first requirement is teleport because the character controller must be set to its initial position. A teleport sets the character to a new position. It doesn't matter where it was previously and if there are obstacles between the old and new position.

Recover from penetrations

…

Convert C# to VB.NET

Fri, 13 Aug 2010 09:04:35 GMT

In our company we do not program in VB.NET. Not that we have anything against it, we have just specialized in C# when we program .NET applications.

We are are aware that our WinForms libraries (DigitalRune Docking Windows and the DigitalRune Text Editor Control) are used by many VB programmers. And they regularly ask for VB example code.

Here are a few ways to automatically convert C# code to VB (or the other way around):

3D XNA Character Controller Example

Wed, 21 Jul 2010 16:20:04 GMT

For the new DigitalRune Geometry library we have created a simple 3D character controller example (including source code).

A character controller, as understood in this context, is a game engine module that computes the movement of an avatar in a game. The input for the character controller is the desired movement (e.g. “move forward with 5 m/s speed”, or “jump”) and the output is the new corrected avatar position in the 3D game world. The character controller has to apply gravity, avoid penetration of walls and other solid objects, handle stepping up/down slopes and stairs, and more.

Collision Detection References

Wed, 21 Jul 2010 16:10:00 GMT

This blog post contains our collection of references for Collision Detection: website links, a list of collision detection libraries, list of books. This post will be updated from time to time.

If you know other useful links, please let us know and we will include them in this blog post.

Collision Detection Websites

This is a collection of various links about collision detection and related topics.

Collision Detection on Wikipedia
GAMMA research group
Website contains a brief description of several libraries.
Geometry Algorithms
Collection of geometry algorithms: clipping, intersections, etc.
…

Physics Engines List

Mon, 05 Jul 2010 10:22:00 GMT

Here is a list of physics engines. This blog entry will be updated from time to time. If you know other useful links, please let us know and we will include them in this list.

3Impact
Game engine with dynamics.
AERO
AgX Multiphysics Toolkit
Animats - Falling Bodies
Ragdoll physics.
BEPUphysics
3D physics engine designed specifically for the XNA Framework
…

Thesis – Character Animation in Real-Time

Sat, 03 Jul 2010 15:56:56 GMT

Like my brother Helmut, I finished my master thesis in 2005. The thesis goes through all the steps necessary for animating characters in games. I thought it might be of use to someone who is just starting with this topic – so I might just write a blog post and put it back online for download.

The Making Of XNA Class Diagrams

Tue, 08 Jun 2010 17:58:14 GMT

If you don’t know how to create class diagrams for the XNA classes in Visual Studio, here is a quick summary of the process.

XNA Framework Class Diagrams

Tue, 08 Jun 2010 17:54:39 GMT

When I learn a new API I like to look at the API using different views: example code, API documentation, and class diagrams. When we started to learn XNA, we created class diagrams for the XNA framework. This helped a lot in getting an overview and seeing relationships between types.

I haven’t seen XNA class diagrams publicly on the internet. So it might help if I post our class diagrams here.

Game Physics Books

Wed, 26 May 2010 13:38:16 GMT

Here is a list of books related to rigid body dynamics and game physics.

Physics for Game Developers

by David M. Bourg

This book is an easy-to-read introduction to game physics. It explains the basics (kinematics, kinetics, forces, particles, rigid bodies, collision response) and several applications (projectiles, ships, hovercrafts, cars, etc.).
The book is for beginners. You will need other sources for advanced topics, like rigid body contacts or joint-handling.

I have encountered several errors while reading the book, so make sure to read the errata on the book's website: http://www.oreilly.com/catalog/physicsgame/

…

Game Physics References

Wed, 26 May 2010 13:28:14 GMT

This is a collection of links about game physics, especially rigid body dynamics, and related topics.

3D World Simulation - Martin Baker
3D world simulation knowledge base by Martin Baker containing a 3D physics section.
Brian Beckman’s The Physics of Racing
The how's, why's and wherefore's of punting a car around a track...
Classical Mechanics
Online course.
Computer Simulations in Physics
Physics Simulations page by Maciej Matyka. Mainly about soft bodies and fluids.
Chris Hecker's Rigid Body Dynamics Information
…

Character Animation References

Wed, 26 May 2010 10:51:35 GMT

This is a collection of various links about character animation and related topics.

Libraries and Products

annosoft Lipsync
Cal3D - 3d character animation library
A skeletal based character animation library written in C++. Open Source (LGPL).
…

Thesis – A Unified Framework for Rigid Body Dynamics

Mon, 24 May 2010 17:30:15 GMT

In 2005 I finished my master thesis about rigid body dynamics. It shows how to build a rigid body physics engine for interactive 3d applications. I am sure it is a good starting point for everyone who wants to learn about game physics.

Welcome to the DigitalRune Blog!

Mon, 24 May 2010 16:49:25 GMT

About This Blog

This blog is our outlet for all stuff we like to share online: ideas, collected pieces of knowledge, useful web links, etc. Our work focuses on software and 3D game development, so most articles will revolve around these topics.

We think of this blog also as our persistent knowledge base. That means blog posts containing link collections will be updated regularly to keep them up-to-date.

For all previous visitors who knew the old DigitalRune website: All “Knowledge Base” pages of our old website are currently being updated and the content will re-appear as blog posts in this blog.

About Us

Most blog post will be written by Helmut Garstenauer and/or Martin Garstenauer. We are the founders of DigitalRune Software.

If you wonder about the name coincidence – we are twin brothers ;-)