Article : Sun- and Lens Flare as a Post Process
by Charles Humphrey
Now this sample has come from my current XNA toy which is the Blacksun engine I am currently writing in XNA 3.1. It uses deferred lighting, instancing and a post processing framework that I found on a great site here, all I had to do was make it engine ready.
If you want to have a look at the effect in the engine you can see it here.
This sample is just one of the elements from the post processing framework in the engine, there are none of the other goodies in this sample, just the Sun post process. This sample has also been created using the XNA 4.0 CTP, so I only had one render target to work with at the time. This means that you can't see the sun being culled behind objects in the scene as I can't create a depth map as well as the rendered scene, to be honest, I still don't have that bit of the shader 100% anyway 
Placeholder in Games
Barnaby Smith shares his thoughts about using placeholder assets during the development of games:
Creation and use of placeholders, whether levels, 3d models, sprites or sounds, has a number of advantages when developing computer games. In this article I discuss some aspects of the use of placeholders in games.
Render Target Changes in XNA Game Studio 4.0
The Shawn of Hargreaves details the changes to the render target API in XNA Framework 4.0. The high level summary of these changes are:
RenderTarget2Dinherits fromTexture2DandRenderTargetCubefromTextureCubeto properly denote the Is-a in the API (no moreRenderTarget*.GetTexture())- Multiple render targets are set at once without explicitly specifying its index and all previous set render targets are unset automatically
- An optional depth buffer for a render target is now a property of the render target itself, which might be shared across multiple render targets if certain conditions are met
For the motivation and details of these changes see Rendertarget changes in XNA Game Studio 4.0.
HOWTO: Resolution Independent Rendering in 2D
David Amador shares his code to work with a fixed resolution on Windows without having to manage the placement of your renderables yourself. Sez David:
Independent Resolution Rendering?? What’s this all about?
Basically a way of not caring what you resolution is. Ever had Gui elements misplaced because you changed the resolution? Or getting out of the screen?
If you are doing a game on Xna just for Xbox360 you can basically use a 1280×720 base resolution and the Xbox will scale the game for you making the proper Letterbox.
But what about on Windows? Or if you use a different resolution on the Xbox? You have to manage that yourself.
I’ve made a small example on how to achieve this.
Light Pre-Pass
Michael Quandt has posted a write up detailing the theory behind his Light Pre-Pass code he released for educational use previously.
Distance field based decal rendering
Rim van Wersch shares an XNA Framework implementation of the Valve paper Improved Alpha-Tested Magnification for Vector Textures and Special Effects, presenting “[a] simple and efficient method […] which allows improved rendering of glyphs composed of curved and linear elements. A distance field is generated from a high resolution image, and then stored into a channel of a lower-resolution texture.”
sgMotion v1.0.0 Released
Tom Looman released his sgMotion library to CodePlex. Says Tom:
sgMotion is an animation library (based on XNAnimation by Bruno Evangelista) and provides full integration with both the Sunburn Engine and the Sunburn Framework.
More at the source.
HOWTO: show drawing items with the mouse in XNA
Jakob Krarup answers an unidentified question in the XNA Community Forums about “how to give a player the possibility of adding things to a game, and storing the position of the added images”.
Geodesic Grid, Part 3
Brian Schaeflein published part 3 of his Geodesic Truncated IcosahedronsGrid series, covering his design decisions about how to store the cells to aid pathfindig.
Geodesic Grid
Brian “JeBuS” I-Don’t-Know-His-Last-NameSchaeflein published a multi part article about Geodesic Truncated Icosahedron (part 2 is here, part 3 is pending) in C# and the XNA Framework. Geodisc Truncated Icosahedrons are “a shape made of hexagons and pentagons” that “has as many faces as needed to make it as spherical as needed, like a Geodesic Dome”.
Head over and grok the code for fun and profit.
Also note his disclaimer in the first post:
I don’t claim that my way of programming is the best way. As far as design patterns and whatnot go, my way works for me, and the code gets the job done. If anyone can offer a more “elegant” approach to anything I’m doing, I’m all ears.