Snow, Biomes

Last week's video was about adding variety to foliage.

Here are three new videos that show something similar but at a larger scale. The first two show transitions from snowy terrain to green terrain. The last one goes from green to some kind of rocky desert.








Do not pay too much attention to the sound, you will hear chipping birds no matter if it is snow or desert.

I did some improvement on the LOD switches. They are still happening pretty much on your face, but in general should be smaller.

Fall colors

Here is a video showing the new skylight feature. Trees now can have different foliage. Adding fall colors was a nice way to test this. These trees share the same foliage texture, it is colorized on-the-fly by the shaders.

Realtime global illumination, sort of

I just added skylight to the realtime renderer. I am very happy with the results. In my opinion it adds a lot of depth, and it is quite fast to compute. You can see it here in two series of screenshots I took for a forest setting.

In each series, the first image is the final results, the second image is the contribution from the skylight and the third is the direct sunlight illumination:

Second series:

This is already looking good, and it runs in realtime. If there was some large character moving around in the scene, you would see its contribution to the shadowing.

The skylight is a standard shadow map, but it is sampled taking a lot of neighbors into consideration. This creates nice soft transitions between areas of light and penumbra.

There are no light bounces here, however. I have been toying with the idea of a screen-space radiosity solution. I think it is possible. If you know of any papers on the subject, please drop a link in the comments section.

As usual I look forward to your comments and criticism.

Realtime Shadows

I decided to give dynamic shadows a quick try. I used a shadow map with percentage-closer filtering to smooth shadow boundaries. The results are quite fast and smooth. The main trick was to run the shadow evaluation on the vertex shader. I realized I had enough vertex density for consistent results. The shadow interpolation between vertices would make the shadows even smoother.

Here are the results.

 

If you wait to the end of the video you will see there is some kind of mysterious object rising from the ground. This is unlike anything you have seen in my videos before. It certainly means something, a sign of things to come...