Ah, finally I understand why you were able to create those nice shadows :0) The trees are not speed tree actors but static meshes. With all the lighting problems coming with speedtree using static actors sounds like a good choice.
But what about the animations (wind effects) have you managed to do that with static mesh trees? Of cource you can use a wind source and foliage layers but usually having the trees animating at the same rate as the grass is doesn't look very realistic.
You could vertex paint the foliage part of the tree and use a clever vertex shader to offset the leaves depending on the wind actors in the scene and add variation by changing the sway of the leaves depending on the objects world position. But saying that the shadows wont move when using the world position offset.
Can you post the material you used for chromatic abberation. I tried it and couldnt get it to work once I ran the game...but it worked in the viewport It would be awesome if you could share that with us.
@blood falcon: sure you can also use a texture to get the same effect, i actually had that in my first version but i was getting some banding against the sky so I switch to the procedural approach.
@amigoface: thanks, that's actually what i had in mind, a little workshop for creating natural environments in UDK will see how it goes. i will hopefully have figured out the foliage actors this week and add some more detail.
@mickyg: Yes it's a StaticMeshes, I just painted a displacement map in Photoshop and used it to displace a 256x256 plane in max, roughly 6000x6000 UU in size. This way you also get specular on your terrain, which seems to be ignored when using a terrain mesh in UDK. Also all the plants are StaticMeshes, no foliage or SpeedTree. I actually tested a lot of different ways over the last two weeks but StaticMeshes still give the best results lighting wise and they work nicely with InteractiveFoliage actors.
Here are two new screenshots, did a lot of work on the terrain material some texture work and fog elements. Also extended the terrain, more shots coming next week.