TLE - A life in pictures

The engine in it's full glory.

Picture from the current build (as of 29.07. 2004). You can see four coloured lightsources, visualized by the small yellow cubes so you can select a light using the mouse to move it around, etc. The Turbot doesn't have proper materials right now as i'm working on this part of the engine, to finally bring shaders and materials together.

Well, this looks even better when you see it for real :).

And here.

As you can see here.

The engine also supports animated textures.

A picture of the console, showing the statistics of the texture manager.

Again per pixel lighting with normal mapping but now with an additional specular map (a simple gray scale texture in this case). This is sometimes called gloss map and i use it to extenuate the specular highlight which looks much more realistic. This shader is practically a copy of the Doom 3 light / surface interaction, apart from the shadows.

Per pixel lighting with normal mapping. Instead of using the interpolated vertex normal, this shader samples from a normal map. The lighting calculation is done in a surface local space, defined at each vertex by three vectors (tangent, original vertex normal and binormal). At each vertex the light and view vector are transformed into the surface local space and then interpolated across the triangle.

To get good results, the three vectors at the vertices should behave nicely and shouldn't jump around to much. Right now these vectors are still hard coded in the vertex shader, so this shader works only on surfaces parallel to the x / z plane. The next step will be to make these vectors proper vertex attributes and store them in the vertex array. I then have to found a method to compute the vectors for arbitrary geometry loaded from .3ds files.

Per pixel lighting, done in a GLslang vertex / fragment shader pair. The vertex normal, light vector and view vector are interpolated and the lighting calculation (lambert / phong) is done in the fragment shader. This gives us a perfectly smooth specular highlight.

Per vertex lighting, done with the old fixed function pipeline offered by OpenGL. The specular highlight clearly shows of the poor triangulation of the floor.

My first experiments with ATI_fragment_shader. At the right side of the cube you see the most trivial fragment shader one can imagine: gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);. This is the GLslang version, the original code using the ati extension to build this shader is so ugly you don't want to see it. On the bonnet of the Turbot you can see a shader which visualizes texture coordinates, using the red channel of the fragment for s and the green channel for t.

The final result with diffuse lighting. The face normals are calculated and then interpolated for each vertex.

Normals done right. As you see here, the engine as able to visualize the normals which makes debugging a lot easier.

For lighting you need normals. The actual calculation was ok but i stored the wrong normal at the wrong vertex and this is the result.

This is my very simple test scene. It consists of the floor, a cube and a model loaded from a .3ds file. Most of the time, i play around with Jakob's (aka Fragdieb) Turbot, a car originally made for GTA 3.