As I hinted on in my last post, I will be discussing the implementation of culling for planet terrain rendering. When the camera is close to the surface, a lot of the terrain geometry is not visible, so it would not be sensible wasting CPU time on generating it or GPU time on drawing it.
Along with the following picture, my video from last week shows quite well what is going on:
Here only the necessary geometry is generated. The implementation to achieve this uses two methods combined: backface culling and frustum culling. I will discuss both methods here along with the implementation…
I decided to do my first tutorial for blender, I first wanted to do it via the description, but that didn´t work, so here is the text:
Please watch in hd if you can, I spent a lot of time rendering here!
Read this to learn how to make this!
So here is the promised tutorial:
Step 1: Making the particle system:
Add a plane and set the particle emission of 10.000 particles to start at 1 and end at 30. Set the lifetime to the same value as the duration of the video in Frames, in my case 500. Set the gravity field weight to 0.
Next add a turbulence forcefield, in the physics tab, I set the Strength to 300, the size to seven and the flow to ten. Adding a turbulence forcefield is like giving the space a density which varies in different places in 3d space which are defined by the size and the seed. The particles will naturally flow to the places with lower density, depending on the strength which goes up to 1000. The flow makes the particles move around in the less dens areas like on paths, the maximum is 10, and the higher the value is the more the particles will stay on that path. The problem with this is that the particles will start grouping themselves to very small spaces, so I added a vortex forcefield with strength 3 and inflow 5 and a keyframed maximum set to 0, which started growing to about a maximum of 6 at about 150 to 200 and shrank back to 0 again at 250. This broke up those groups in the defined area, which you can especially see when the particles are released again. I then rendered the particles as little halos, which is the first clip you can see.
