Off the Map Part 5

I haven't been posting for a while and its time to start catching up on the work I have been doing on the Off the Map project. So one of the things I have been learning to make and producing for our groups Off the Map has been foliage like grasses and flowers. This was an interesting process because it was expanding on things I had learnt about but didn't fully understand and utilize last year for the tree project.

I started by with grass before moving on to the flowers and other foliage but the workflow was simple once learnt and could be used on anything you wanted. I would start by actually modelling the grass blades. Making a cuboid and then modelling into it and extruding the vertical edges so that w=hen the model was turbo smooth there would be a crisp clear edge that could be baked in. I would then place the grass blades together all textured with a simple gradient material in 3DS Max and twist them so they looked like they naturally bent under the blades weight.

The next step was to bake them onto a plane with an AO, Normal and Diffuse map with an alpha channel with a little anti aliasing so there would be no bleed in the channel. This would create a clean clear alpha and little cleaning up would have to be done. To create a more clear crispness to the grass I overlayed a greyscale normal map onto the diffuse to add that crease down the centre of the blades.

This process would be repeated with the flowers where I would model and texture before baking an cleaning up. With the larger leaves of flowers I would make a subtle height map and AO for the veins in the leaves.

Once these textures were made I would place them in engine and use the two sided shading model in UE4.7 to get some clear subsurface scattering where the light shines through the blades.

The final step in the process was to simulate the wind across the grass. Even though the unreal engine has a simple grass wind node in the material editor I wanted something that looked much more natural then the results produced by it. I used a system that pans a normal map across the world space the grass is in creating a more natural wind that doesn't move the bottom of the grass as much or at all and creates occasional mexican waves in the grass like the wind in real life.