Brighten up shadows of groundcover shapes in T3D

Note developers: This post is written in a way for artists to understand

GroundCover is an ideal way to replicate shapes on vast terrains without the cost of fps comparing to Forest Objects. The default groundcover billboards are default rendered with the same side, regardless rotation. This is depending on the parameter windDirection. If you'd change the windDirection you'd notice that normals are rendered on the billboards. If you're satisfied with the current setting, avoiding dark shadows that look unnatural on tall thin vegetation, you'd certain having problems with 3d shapes as groundcover.

While T3D has most things to look like a modern engine, you see that most kept avoiding the 3d shapes as GroundCover, partly because of the overly dark shadows. So most groundcover objects you see are the default billboards instead. For some time I'm trying to solve this issue in the code, but kept on getting unsatisfying results. Now I found a really simple way of getting rid of the issue, or even getting control on the amount of shadows (normals). This might also do it for you until we find a better solution; somewhere in the code.

I added a normal map to the material that simulates light always coming from above. To get the right direction of simulated light, I blended (multiply) the colours 128-255-255 (Top Left) and 255-255-128 (Top Right), the result is 128-255-128.

The shadows on the 3d shapes as groundcover are default almost black like this:

.

Now the solid colour (100%) applied as normal map in the material will remove all shadows:

.

By adding the colour 128-128-255 you'll reduce the effect and therefore bring back the original shadows.
This way you gain control on how strong the shadows appear.

_100%
_75%
_50%
_25%

Click on each image to download the matching compressed DDS file.
Download the Photoshop file with the colours here

Adding a solid colour will work when you're not already using normal maps in that material. To brighten up the shadows with existing normal maps you can create a blending layer in your imagining application (like Ps). Setting the solid colour as Detail Normal Map in the Material Editor, will not work.

The good thing is, that this trick can also be applied on other stuff where needed :)

Finally do I hope we find a way to apply the wind effect on 3d shapes as well, and not only being reserved for the groundcover billboards.

Cheers, Nils


If you happy with the result then post a shot here for us to see,but please don't exceed the 720 pixel width, thanks!