Recently I got a PM with a question about taillight shading of my Felicia mod, which inspired me to start a thread, where modders can share their techniques to learn from each other to make more high quality mods in the future. Therefore I will start with a few visual "tricks" which I have used and might be helpful
A texture-based ambient occlusion
Sometimes dark points are not enough for a smooth ambient occlusion. In those cases a texture can be used. Professionals can bake it, beginners can draw it by hand (I personally prefer drawing). This texture can be combined using transparent layers.
A shaded roll-cage
A strange looking roll-cage shading is a common problem of many mods. To enthance shading approximations of a cage a simple texture can be used. For a better result, the alpha channel should correlate with black color which will remove unwanted gloss under the ceiling.
A Felicia tailight effects
I have used multiple "tricks" to build this one. First the "yellow light around a bulb" is done using a texture. The default color of the taillight is red which hides a white places in the texture. The color of a lit taillight is yellow, which overrides the red color.
Secondly, IRL the tailights reflects daylight from various angles. To approximate a distribution of light in a tailight I have tweaked normals using some additional triangles, which are not visible. If you turn the Škoda Felicia mod (using a 3rd person view) in the LFS, you can see, that tailights are shaded quite differently (despite not being fully 3D).
Edit: feel free to post your own tips and tricks in this thread Anything about shading, topology, suspension approximations, realistic aerodynamics, engine sounds etc. could be helpful
A texture-based ambient occlusion
Sometimes dark points are not enough for a smooth ambient occlusion. In those cases a texture can be used. Professionals can bake it, beginners can draw it by hand (I personally prefer drawing). This texture can be combined using transparent layers.
A shaded roll-cage
A strange looking roll-cage shading is a common problem of many mods. To enthance shading approximations of a cage a simple texture can be used. For a better result, the alpha channel should correlate with black color which will remove unwanted gloss under the ceiling.
A Felicia tailight effects
I have used multiple "tricks" to build this one. First the "yellow light around a bulb" is done using a texture. The default color of the taillight is red which hides a white places in the texture. The color of a lit taillight is yellow, which overrides the red color.
Secondly, IRL the tailights reflects daylight from various angles. To approximate a distribution of light in a tailight I have tweaked normals using some additional triangles, which are not visible. If you turn the Škoda Felicia mod (using a 3rd person view) in the LFS, you can see, that tailights are shaded quite differently (despite not being fully 3D).
Edit: feel free to post your own tips and tricks in this thread Anything about shading, topology, suspension approximations, realistic aerodynamics, engine sounds etc. could be helpful