Blender School: Maarten Nauta's landscape lessons

 This Blender School lesson will be dedicated to some of the pearls of wisdom that brilliant landscape artist, Maarten Nauta scatters during his Youtube videos (example: Creating Realistic Environments with Blender.)

Preproduction and reference

Golden rule: DO NOT JUST RIGHT IN.
Write down what you need from an effort. Creating an animation will require a different starting point and a different outcome. Set boundries for the client, even if you are the client. Dawn shot? Weather? Biomes? Where is the camera? Where will the camera travel? The more things you nail down, the less chance that your effort goes astray.

1. Project Scope
2. Focus Points
3. Solid Concept
4. Get Your asset library

Reference

For more authentic biomes, consider using iNaturalist to build a shopping list of authentic plant assets.

inaturalist.org is a great souce of real-world biome data.

Maarten - "One benefit of inaturalist is that it gives you photo references from your chosen biome. This is important because the look of plants can change depending on the biome. For example, A Scots Pine in the Baltics looks different in Mediteranian environment. It's an extra step but it can help.

Reference with a mood board.

PureRef is a great tool for quickly creating a reference board.

PureRef (In this case, for Halo Tech)

Golden Rule: Animate at the beginning

If you are creating an animation, don't wait until your detailed landscape is built before doing the first pass of your animation. it will be faster and more stable if you get it blocked out while your scene is small and simple.

Big terrains and grass

In Maarten's example, his terrains are more then 20km front-to-back. Huge! When you apply a grass shader to a large terrain then roughness never looks right. The shader is treating your grass surface as a flat plane, which it absolutely isn't. Grass scatters light really well, it only reflects in exceptional circumstances, such as when it is very wet.

Turn the specularity down to 0.01 or 0.001. You could almost turn it off.

More from Maarten:
"Basically what I'm trying to say is that roughness only dictates how directly light gets reflected. At a high roughness lots the light scatters in lots of different directions causing the reflective sharpness to lower. However roughness of a texture can't emulate the 'absorbtion' (don't know a better word to describe it) of lightrays that happens with lots of foliage. Turning down the specularity lowers the amount of light that gets reflected which kind of emulates what would happen when a lightray hits a real 3D patch of grass rather than a flat grass texture."

Atmospherics

Volumes are the best. They are expensive, result in noise and flickering, but they just give you the realism. You will need high samples. 500-1000.

Anistropics:  0.5 More cinematic, as it congrigates the density of the volume around the lighter parts of a scene. When you use a Gobo, you get a deeper and complex and potentially realistic scene.

Flickering from noise reduction: Consider rendering as separate passes, so that you can apply tweaks to your volume pass, such as a slight blur.

Trees

Maarten uses Speedtree. It's Unreal-based and deeply propriatory -- as in the developer hasn't made it Blender-friendly. Obviously you can still use it.

Tip: Trees that are going into a forest, consider stripping their mesh of lower branches as they will be hidden within a forest. Leave the full branches for forest edges and isolated trees.
 

Optimise your background assets!

Don't use full detailed models in the viewport. Even after years of improvements to Blender's viewport performance, and the move to Vulkan has made a massive different, it still pays to use simple proxy objects in the viewport.

Vegetation and noise

Rescaling plants and trees for realism is very important. However, using a noise for this is not realistic. Vegetation is not random, the noise it presents are based on rules concerning moisture and the neighbouring plants. 

Getting good vegetation is about applying rules instead of random.

Geo-Scatter

Maarten uses manual scatter more than is recommended because it provides the artist with direct control over where stuff scatters. "Easy and optimised". 
Consider using the Reduced Density, right up to 90%

Scattering grasses

Maarten hides this wizardry behind his Patreon. Apparently the knowledge was gleaned from Max tutorials from industry artists.

One this is for sure YOU CAN'T SCATTER realistically on big terrains. You have to understand how hinting at distance grass is the only possibly method. Many millions of grass scatters on top of everything else will crash your system or take too long to render.

Tip: Consider baking terrains into meshes that you can decimate. Subdivision modifier is a memory hog and can be unstable.


Tip: Render with Tiles to reduce VRAM 

Cliffs and terrain verticality

Any displacement map-based terrain is going to suck and areas of steepness. A displacement can't express detail in these areas. If you need detail then you can 1) do a massive manual refinement of the mess, manually adding more geo' into the baked mesh. 2) Add some non-displaced or differently displaced assets into the cliff area.

Stolen from Maarten's Rise and Fall breakdown

The cliff details look like they perfectly follow the underlying terrain, which makes me thing this element has been modified manually to add the vertical displacement.

Maarten's Rise and Fall breakdown - How good is that? Very damned good!