Question Best way to place a lot of trees in a tilemap

I'm placing trees on a 2D tilemap, so some trees are in front and should obscure the trees behind them (like in the attached image). So each tree's TilemapRenderer will need to have the appropriate "order in layer" value so that it obscures trees behind it and is in turn obscured by trees in front of it. Is the correct way of handling this to have every tree in its own Tilemap component? That seems like by far the easiest way of going about it, but I'm worried that having a lot of Tilemap components within my Grid might be a bad idea.

The alternative is to have multiple trees on the same Tilemap, in which case I'd need some complicated logic to make sure that the Tilemaps all have the appropriate sorting order so that every tree in that Tilemap is drawn correctly relative to the trees in front and behind it.

Is it OK to potentially have hundreds of small Tilemaps in my Grid, each of which has just a few tiles for one tree?

 

In such situation why use tilemaps at all? Why not just create regular sprites and use the sorting axis to ensure that correct one is on top automatically without having to assign "order in layer"?

 

You want to change your TilemapRenderer from Chunk to Individual Mode. This allows each sprite on the Tilemap to be sorted individually against other objects and characters. This will accomplish what you want automatically without all the complexity of managing multiple tilemaps. You will only need 1 tilemap for all of your "tall" stuff, like trees.

You also want a Transparency Sort Axis of (0, 1, 0) which ensures that sprites are sorted by their y-value. To set this, it's either in Project Settings > Graphics, or it's on the 2D Renderer asset if you use the 2D Renderer. This is automatically the default setting if you created a new URP 2D project.

The floor, on the other hand, can use Chunk mode and should use a smaller/negative Order in Layer. Chunk renders more efficiently, but you lose the ability to sort individual sprites against a character for example.

More on 2d sorting: https://docs.unity3d.com/Manual/2DSorting.html
More on tilemap rendering: https://docs.unity3d.com/Manual/Tilemap-Isometric-RenderModes.html#individual

 

The problem with this is that each cell in the tilemap can only have one tile, so all of my background trees would be erased when I draw a foreground tree in those tilemap cells. For instance, in the attached file, several of the tiles for the tree in back were overwritten by the front tree's tiles since both trees are in the same tilemap. Am I overlooking something from your answer?

 

You want your trees to be a single sprite. Put the pivot point in the Sprite Editor down at the bottom of the trunk. With Individual mode, the single-sprite tree will then sort from that single pivot point.

 

Good idea, that's what I'll do. I guess I was overcomplicating things using the tilemap.

 

Thank you, that gives me exactly what I'm looking for.