Working on Implementing Glow Effect (Cg) on TGE

During the last few weeks, I've been working with proping up my TGE so that I could use Cg to prop up the graphical engine. I'm completely aware that TSE would potentially be a better choice if I wanted to use Shaders, but as the project I'm working on is rather crucial, I need to be sure the game could be delivered as promised. That is why I stuck with TGE and tried to do the best with what tools I had at disposal.

Let me show you the original game screenshots that I've used TGE in:

I do find the results to be pretty decent. Though not state of the art graphics, it wasn't shabby, and looked good to my early trial with a number of casual game players (relatives, friends popping by my home :P).

After presenting that to my customers, I've found the major comment is that they wanted the scene to look more surreal. After talking through it, they wanted some sort of glow effect to make the scene look unreal or like in the game scenes from heaven or hell. Though I attached lights to my player character, that light wasn't enough glow.

I had a few workarounds that I thought about doing. The major problem is that I can't implement things that require too many CPU cycles considering the huge demand at the present. The first I thought to do was to was to add particle effects to the player. That was kind of taking the focus off the point I didn't implement the glow-effect. The other is to double render the player and use different blending options to get the player glow. This method requires more rendering passes, and since the current game is extremely taxing on the CPU/memory, I've decided not to do this. I remember I used to use the DRL resource, and I liked it extremely. However as my game is already using too much CPU, I didn't think I should use it with this project. The last idea that came to mind is to use Cg to implement the glow effect. This is an ideal solution as it places less stress on the CPU as the extra processing is sent to the GPU.

On a side note, I could always simply ignore the request, but since I had time (was a few weeks ahead of schedule) I decided to try to experiment by adding Cg support to TGE.

The first part of was easy. Integrating Cg to any program is easy. There are many resources that point to that in the Internet. I myself also did write a few DirectX + Cg programs before. The next point is to write some vertex/pixel shader programs to create the glow. In this part I used to work with my own Glow effect in RenderMonkey before so that was a huge help. On a sidenote, there are also many useful resources that is useful on this topic and the one that I liked was from the following url: (collective.valve-erc.com/index.php?go=tron1). As I had some parts of this done already, the rest was for me to figure a way to merge it with TGE which seem quite a difficult task at the beginning.

During the first few days of implementing, I had a torrid time getting things right. At times, everything crashed, at times I get things opposite of what I wanted. As noted, the following picture shows alittle about some of the things gone wrong:

After a little more probing, I managed to fix a few more things, though unfortuantely I had the whole picture oversaturated instead of making it look like glowing. Also there were many rendering problems like when the scene became too saturated, the characters all disappeared! Now that is what I call bad programming on my part :P

However after a period of debugging, and going through the rendering engine TGE, things were dawning. The TGE rendering engine is rather decentralized so it takes some time to go through the different parts of the engine to find what I wanted. Anyway, after another sleepless night, programming along with watching the WorldCup, somehow I managed to get things alittle like what I wanted.

From the last pic, there is a slight glow effect with the whole scene which is basically the effect I wanted. Though the effect was created, I don't think it is adequate yet. I believe I need to tweak things comprehensively to make it look better. However, I was more preoccupied of getting things done than actually making it look good since the start, so I guess within the short period of time, that was good enough :P

Anyway, for the future plan, I think about making the Cg support tool I use a little more customizable as I would have to create 2 major themes for the game (heaven scene and hell scene) and it won't be the best of idea to hardcode everything when I need to change parameters and shader programs for every stage.

Thinking about it, I haven't been putting much thought in that... and my code is a freaking mess, much like a huge bandage wrapper attached with chewing gum to the Torque engine. Hmm... that isn't good is it?

I got to think more about it soon, but considering the Germany vs Poland match is starting soon, I guess I'll postpone that to sometime in the future :P