Terrain GPU Based Shadowmaps

Hi Guys,

Just writing a quick blog here to showcase the new GPU Based Terrain Shadowmaps. These are shadows casted by the terrain that are now realtime and react to the lighting direction instantly within 2ms or less. What this means is that you dont have to edit the terrain and then bake the lightmaps into the surface. Instead the shadows are generated as the light moves passed a certain point at which point a compute shader on the GPU takes the height information and then calculates the shadows extremely quickly and efficiently.

This is working in both DX11 and OpenGL.

The really cool part is that we have also applied it to the standard PBR models in the scene so they pick up the lighting too, and with a very simple height based lighting algorithm to ensure that once a model goes above the terrains peaks or shadows that it stops receiving shadows which allows very realistic terrains to be used.

Also, when using a large terrain size like 4096 and 20km world, the shadows are just as fast in realtime leading to some sweet visuals.

On top of this it also sorts out one of the major problems we have had with water where the specular reflection was strong all the way into the shadow of the terrain breaking immersion.
This no longer happens and the terrain shadows reduce the specularity of the surface creating a much more blended scene.

Heres a video to show more :)

With a little more time, we should have more of the grass system to show for the terrain also.. so stay tuned!!!!!

And as always, have fun developing everyone and see you next time!