TGE Shader Pack

Download Code File

This Shader pack contains my previous Normal mapping resource bundled with 3 other shaders on DTS objects. The uploaded file contains 4 source files which you need to add to your existing TGE installation (start from stock TGE + the MK and replace the 4 files with the files in the archive)

The materials.cs file shows a sample of how to setup materials with this new system

Shaders included: Skin Shader, Fur shader, Normal map shader and the toon shader

Usage Instructions
The default MK material system has been somewhat revamped to accommodate for the special setup needed to render these special effects. I will briefly try to explain them. If it does not make sense, or if you need some extra info, please feel free to post a comment and I'll answer them.

1. Parameters:
Parameters (called uniforms in GLSL) are just that - parameters. The best way to understand this is to consider a simple example. Let's say you want to use a particlar shader to render something in some variation of red, depending on, say, the lighting position. If you want to write a shader that worked in a similar manner, only this time rendered in green, you'll need to rewrite the entire shader again and load it into memory. This is a serious waste of time (when you'd be rather writing better gameplay stuff)

So what do you do? You parameterize the color (or whatever you think is going to vary) and set it from script. That way, you define one shader block and use it with different parameters to achieve the desired effect. The modifications I've included support only 3 types of parameters - vectors, floats, and
integers

2. Blend modes:
Blend modes in OpenGL are what control transparency. There are different types of blend modes that you can set depending on your need. In this code, only 3 blend modes are included - (SourceAlpha, 1 - SourceAlpha), (SourceAlpha, One) and off. For more information on Blend modes, you might want to try
this

3. Multipass rendering:
Multipass rendering is quite straight forward. You basically draw the geometry over and over again, using a different parameterized shader each time. The shader bound is the same, only a certain parameter (in most cases the pass number) is altered. Based on the pass number, the geometry is altered in the vertex shader or the fragment shader and a plethora of effects is possible.

In the example set above, the fur shader uses the multi-pass effect. When you flag a material as being multi-pass in script (a method I shall describe below), you can define a uniform variable in the shader, called passNumber (case sensitive) which gets updated automatically by the engine, based on the current render pass.

4. Material Scripts:

Once you get the basics out of the way, setting up the materials is quite easy. Look at materials.cs for for more information on how to do this. You can basically set blend modes as:

blendModes[passNumber] = (either -1, 0 or 1)

-1 disables blending, 0 sets it to (sourceAlpha, 1 - SourceAlpha) and 1 sets it to (sourceAlpha, One), which is used by the fur shader. So, for instance, you have a 2-pass material, and wanted to enable blend on the second pass only, with a (SourceAlpha, 1-sourceAlpha) setup, you'd do:

blendModes[0] = -1;
blendModes[1] = 0;

So much for blending. Simple, isn't it?

To parameterize the shaders, you'd define the shaders as usual. The parameter would then be defined in the shader.vert/shader.frag file as: (assuming you have a float parameter and a vector/color parameter)

uniform float myVar;
uniform vec4 myColor;

For the example above, we have 1 float parameter, and 1 vector parameter. So, in our material script, we write:

numVecParams = 1;
numFloatParams = 1;
floatUniforms[0] = "myVar";
floatvalues[0] = 1.5;
vecUniforms[0] = "myColor";
vecValues[0] = "0.3 0.3 0.3 1.0";

This indicates that you are passing the values stored in the vecValues/floatValues array to the corresponding variable names held in floatUniforms/vecUniforms. This makes the entire thing a little more flexible and intuitive.

You can see the inherent versatility in this method, if you look into the provided material scripts - there are two materials (toonShader11 and toonShader) which use the same shader. They pass different values to the color parameters.

And finally, to create a material with multipass rendering, and say, 3 render passes. You'd add

multiPass = true;
numPasses = 3;

to your material definition block. Then you can define:

uniform float passIndex;

inside your shader (look at furV.glsl for a sample). This variable is automatically updated by the engine everytime it goes to a new pass. So, if you want to do someting special on the third render pass in your vertex shader, you'd do

if(passIndex == 3)
(do something special)

inside your vertex shader.

I've tried to be as brief as possible. If you want more information, please feel free to ask! I'll be around more often from now on (hurray!), so I'll get back to you.

Cheers and best of luck with your projects!

Koushik

P.S: If you want to see some screenies, you can take a look at my last blog post :)