The best approach is not to try and model or paint the detail yourself but design a program which can "grow" the graphics for you... The images of branches below are generated by a custom script in ImageJ, this is an example of procedural generation, which can generate huge detail very quickly. The graphics are made up of three parts; the alpha map (black shows that area should be transparent, white indicates opaque), the bump map (which adds depth and shape to the shading of the texture) and the diffuse texture (which provides the colour).
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTa6CT7sHtdhZ3mIpmEg7ZCrHYM0gAdIrcLMqZzFAlg1qF9RinDvXe1OMPdqSR2XaTHUBrUhNG47K3yaXZ7pJxK-bLbvxNyhMGQ7KMLfzMlzavl2930hRVNrxuGkQXcXTUH_AyexzCKDY/s400/alpha.png)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6n5DTLK_qY0iRWjlJFgLScP6d4t1MS6fR0WGYnMmQPuFUG1XuN_CtWG1dZAkHtERWfUWrYYBWevJCIJOslgoduFHufvC1cw-FA913NX3stPVjLqDBJCh2saDm9zXlRkRFJtPdq8XdU5o/s400/bump.png)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgawcTEZvdBpMVVCcJ6fZPLjgZ1jQF90ccMHIPeA5nLcpY_NMNujQgP2xrYem8ks3JPvb-jG-YEvQtUahZkAqU0TOQxOu2Cpl_xSQVxhsf2g8TJXgIqDbBZdRBd9STSjvX99QKiT6vLdoo/s400/diffuse.png)
Putting 6 of these computer generated textures together a pretty detailed tree can be made with just a few polygons. These trees render quickly and could be used in a computer game.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEExJdx8xHsEHprJngdCZbWywfNdGiLD9GuSOUwHPHHU2mqiwJAjUsVurpzPVmfMXy_6BREw274p2D-zM6MWJVB1Xkdt6JqVaXis9XWpQz3HOAJtThI1jLJgNuPVuMsgEzzEg4yjnT1ZQ/s400/tree.jpg)
ImageJ - Procedural generation of textures.
Blender - Creation and rendering of 3D models.