Is it possible to use baked lighting with Tilemaps & Sprites?

I'm building a 2.5D game with 2D tilemaps, sprites, Spine animated things, and 3D perspective camera, lights, some scenery. Unity 2020.1.12, URP, custom (PBR master node) Shader Graph for all the 2D stuff.

Baked lighting works fine on MeshRenderers but it looks like Unity won't bake anything for Tilemaps or Sprites ... is there any way to get this to work?

SG looks like this:


Scene (the spot is realtime and works, tree/pole shadows are from a directional realtime light which I want to be mixed (baked on static ground/trees), point light on left is baked and doesn't do anything at all):


Same scene in 'UV Charts' scene view mode (looks like GI is only seeing UVs for the mesh ribbons that make up the world 'edges' under the tilemap):

 

Bump ... really don't want to give up on tilemaps & sprite workflows in order to get performant lighting!

 

Many thanks for the reply, has given me an interesting day poking at bits of Unity I've not used before.

Sprites getting lit via light probes is neat to see ... using a baked directional (or spot) light there are no shadows cast by the sprites though (shadows will cast/receive as expected with a realtime light). Is there any way to remedy this?

I'm assuming this is related to the issue I'm seeing where if, for instance, there's a light behind a sprite then the front face will still be lit (?)

The ribbons are mesh renderers already (using probuilder) and I *think* are working fine ... do you have any suggestions or pointers for how to 'convert the ground' (as in, a tilemap) to a mesh renderer?

 

@KEngelstoft Thanks again for the pointers.

I happened to have low poly meshes on the decorations (like the trees) that sorta match their shapes from a (probably way over-engineered) raycast/occlusion system. Setting those to 'shadows only' I can get some nice baked lighting like this (the floor is a default cube):



Remaining issues with this setup:

• I can't see a sensible way to get point lights/probes to work with sprites where the point light is behind the sprite. In this scenario, sprites get lit as though the light is in front of it (or, I guess, more accurately, around it). The front/center tree is an example of this.
• Sprites indeed don't support baked shadows ... so no nice tree-casting-shadow-onto-another-tree, etc. In the screenshot above the big tree on right should darken the tree behind/to its left. With the blurry shadows that's a lot more tolerable than with hard shadows.
• No way to bake shadows onto a tilemap.

It would be great if there were a way to achieve that last part ... otherwise, this has been an interesting couple of days exploring what's possible. Again, thank you.

 

This sounded ... complicated. Well beyond my shader skills anyway!

I did happen to find 'Probe Anchor' in debug settings for Sprites which I'm setting lower to the ground and in front of the Sprites to get the sprite to blend probes on the 'front' side / near where light sources actually are.

For posterity. The setup I've ended up with is:

Have a sprite:



Add a thin (0.1 extruded) polyshape mesh using probuilder:



Set that mesh renderer to 'shadows only'

Add an empty game object slightly in front of the tree, use that as 'probe anchor' for the sprite.

Using https://assetstore.unity.com/packages/tools/utilities/magic-light-probes-157812 to auto-add light probes ... this took a lot of tweaking to find usable settings ... this is kinda difficult to show in a screenshot but the end result leaves probes on the front and back of the trees:



This is what the scene looks like without the probe anchors set in front of each sprite:



The left big tree is dark (because it's using probes high up/away from the light), trees in front of/closer to the fires are lighter than ones behind.

And with the probe anchors set:



Trees on the far side of lights are getting lit up more, large tree (on left) is getting lit by probes near the ground. Nice.

 

Minor update on this for anyone going through the same journey - https://github.com/sr4dev/Unity-SpriteAssist gives a much easier way to create sprite meshes (vs. using probuilder as I was previously). BUT, in order for GI to work, the generated meshes require normals ... so I needed to add this to the UpdateMesh() method:

Code (CSharp):

1.             Vector3[] normals = new Vector3[v.Length];
2.             for (var i = 0; i < normals.Length; i++)
3.             {
4.                 normals[i] = Vector3.back;
5.             }

 

Was this the best solution to the problem in the end? I am also wanting to have sprite shadows baked in but its a bit of a pain to have to make a mesh for each sprite.

 

'Best' IDK ... was workable for my game but the entire workflow does feel very hacky!