Real time grass created for Unreal Engine 4 archviz projects
I've always been obssesed with grass in external archviz. A great amount of time in my projects is always dedicated to achieving a nice looking grass.
I started experimenting with Unreal Engine for archviz in 2012 (UDK). The graphics were great but no quite there yet. A couple of months after UE4 launch in 2014 I was sure it had the real potential to replace Mental Ray and Vray as my main archviz tool, but just one thing was holding me back: the grass...
So I' started studying ways to reproduce Vray-like grass in real time. It is not an easy task because you can't just model every single blade in 3D and let it render for a couple of hours. For real time graphics you must keep polycount down or it will be impossible to run such a scene even on the most powerfull graphics card.
This is the last version of my grass and it includes all the techniques and tricks I've learned during the last two years... It's basically a bunch of cards with clusters of grass blades textures made in SpeedTree. Vertex normals must receive special attention to hide those cards. On top of that, the UE4 material has a complicated net of nodes to simulate shadows and reproduce color and lenght variations. An extra layer of geometry is responsible for the scattered clovers, leaves and flowers. It has dynamic light only.