Fullscreen Glow

I added support for fullscreen glow to my renderer yesterday and overall I am happy with the results. While this effect is not full blown HDR color correction/bloom/etc., it gives the scene a softer look while making the luminous colors brighter and providing some anti-aliasing on the side. I realize some people feel these type of post-processing effects are overused, but I like it. If you disagree, it will be one of the detail settings in the game that you can turn off.

WARNING: What follows is graphics nerd speak...

Here's the rundown on my implementation:

1. If glow is on, we render the scene (minus UI) to an offscreen rendertarget, otherwise proceed as normal while rendering to the backbuffer.



2. When we're done rendering the scene, switch the rendertarget over to one that is 1/4 the size. This fraction can be larger or smaller, but I made the performance/quality tradeoff at 1/4.



3. Set the full-size offscreen rendertarget as a source texture.


4. Set a fullscreen quad as the vertex source.


5. Sample from the offscreen RT now... we are effectively downsampling the original result.


6. The output of this stage is this sample, with the alpha channel containing the luminosity (or grayscale) of the color.


7. Set the alpha blending mode to additive.


8. Set the rendertarget to the backbuffer and another source texture to the downsampled luminosity RT.


9. For this pass, sample the downsampled luminosity texture with a 3x3 gaussian blur kernel. Again, the size of the blur can be larger or it can be a box filter. This is also a performance/quality tradeoff.


10. Add the blurred luminosity value to the sample for the scene texture.

Here's what the final result looked like:

Gameplay Footage

I put together a video of the game thus far after I got it to a state that represents the core gameplay.  Graphically, I plan to add shadows and some postprocessing (namely glow) as well as a prettier display for scores and lives.  I also plan on adding more enemies and some other goodies before making a download available.  Speaking of which, people have asked me when that is going to happen.  My goal is get this done sometime in the middle of March.  I am limiting the scope of the game to a single level score challenge and yes, it will be free since it's such a small game.  I intend to start a much longer term project sometime around April, but more on that later since I haven't really narrowed down the pool of ideas :)

As always, I welcome comments and feedback.  Thanks and enjoy.

Pinky and the Cave

 

First of all, hello world and welcome to Roach Puppy Games.   I know the size of my current audience is about 0-3 but I hope to change that and what the hell, I'm gonna blog anyway.  I created this entity (I use that word too much) to brand my creations and to have a single place to talk about my work other than my blog.  It all sounds very official but it's just me in my home office in my free time.  Up until recently, my game development efforts have been very focused graphics demos, engines and small game prototypes.  I've been refocusing these last few months, motivated by the IGF and successes of small teams due to the rising popularity of casual and indie games.

Introductions aside, here's a small preview of my current project Pinky and the Cave.  I've been working on it for about a month in order to flesh out my engine, but I decided to continue work on it since it's turning out to be a pretty fun game.  Think Geometry Wars if you were swinging on a rope the whole time.