I am making a low poly game and after importing a low poly tree model I made in blender, I was disappointed to see how flat the surface of the tree in the shadow looked. I would like to see the details even on darker surfaces. I guess it has something to do with the lighting of the scene but I have no idea what settings to change. I also tried messing around with ambient occlusion but I don’t get the effect I am looking for. I am using the unity built in render pipeline.
Thanks in advance
What I want (side of the tree enlighten by the directional light)
As you know this is not a realistic behavior so you can add another directional light with or without shadows on the other direction with lower intensity
Also you can use layers to only apply directional light effect on your tree models
baked lighting will help significantly here. you need bounced lighting on the back of the tree (comes from baked lighting, or other forms of global illumination), not just direct lighting
Hi. This issue is caused by the fact that the areas in the shadow do not receive indirect light. Depending on what kind of game you want to create, there are several solutions for this problem.
Ambient Oclusion - This option can produce relatively good results, but the final effect depends on the shape of the trees. For example, AO works relatively well on the Pine tree, but barelly makes a difference on the Bitch tree
Left image AO Off, Right image AO On
Left image AO Off, Right image AO On
Setting the Environment Lighting to Gradient - By setting the Sky Color to a brighter color compared to the Equator Color, you can end up with something like this.
You have to be careful with this method, because if you make the Sky Color too bright, some parts of the level will look brighter than they should.
Baked Indirect Light - This is the option that produces the best result. Left image without Indirect Light, Right image with Baked Indirect Light
The Baked Indirect Light has some limitation.
It can’t be used if your game has a day night/cycle or lights that turn on/off, since the Indirect light is baked in the editor into lightmaps and can’t be updated at run time.
If you have a large number of trees, thousands for example, the total size of the light maps will be big. This is not good if you work on a mobile game.
Some of the lighting gurus are probably going to balk at this, but if you want reasonably good (NOT physically accurate) results, you can just use 3 directional lights in different directions. One of them will have shadows and be very strong. The other two will be much weaker, no shadows, and just exist to light things from other directions or give very slight color variation. See here for a (short, readable) explanation:
In the context of a game where the player perspective can move (at least on the XZ plane) and an outdoor scene, the key light would be the sun at a rakish angle to cast some rakish shadows, the fill light would be the sky (directly or almost directly above) and the back light would be opposite the sun and lower to the ground (but probably not from below).
For your final game, you may want to use GI of some sort (baked indirect light and baked AO) if your game allows it, but a quick technique like that will make iteration a lot faster AND make the GI look better once you’re ready to bake. One thing to take note of is if your sun moves and you have a day-night cycle, in which case this all gets a ton more complex.
(but I’m definitely not an expert on lighting games; most of my lighting experience comes from lighting reef aquariums for coral growth and coloration, which is a little different)
