Question Design paradigm for 2D illustrated isometric games?

Hello all,
I'm quite new to game design, but I've worked on small projects here in unity. However, I plan on making a 2D isometric game that features hand-drawn illustration as assets (think something like Hades or hollowknight).

I've always worked with tilemaps when designing levels. However, this time, I'm working with an artist who wants to hand draw the levels/stages and characters. What exactly is the best way to going about designing games when you want to illustrate everything?

Should the artist just hand me illustrations with layers of foreground, and me implementing collisions and prefabs, or should I be working with them to make a vague outline of a level with a tilemap before they illustrate over it? How exactly does one go about creating collisions in a game when they're working with drawings?

Thanks

 

Take a look at this screenshot from Hades. Their scenes look like they're always composed of not too many different elements, often re-scaled or mirrored.

Some observations : numbering some obvious repeated sprites
- #1, #5, #6 - these are all separate pieces manually placed on top of one another.
- #1, #2 - same as above, two separate pieces placed on top of one another.
- #4 & #7 (far right): it appears that they will add another sprite (#4 : green line) on top of another (#7 - siding) just to increase variety.
- Notice the mistake near the center of the screen. They do not bother to have their trimming pieces perfectly fit on corners. The player isn't concentrating on that anyway, even though it's in the foreground. That edge, too looks like it's a separate piece. The stone floor is probably very flat. Using a separate sprite for the trimming again allows more variety.
- Shadows appear to be placed manually. If you look closely at the #3's, they mirror that sprite but the shadow does not flip, so those are separate sprites.

If I had to guess, I would guess they do not use a grid at all, since you can see very slight deviations from grid placement.

For the artist
If you want a similar kind of layout, I would encourage the artist to draw separate sprites that can be used over and over again. Certain sprites might even be drawn in grayscale so they can be recolored more fully for variety's sake. They should experiment with their own sprites to ensure they can be combined together well. Special details (facades, ornamentation, things like #4 green line) could be kept as separate sprites so they can be sprinkled on the scene to reduce repetitiveness.

Collisions
For collisions you could use the SpriteEditor and supply custom physics outlines so you colliders are at the base of the object. Alternatively, they may just use a 2d polygon collider that's done by hand, especially for the edges of the room. That would limit the # of colliders and erase gaps.

Tilemap
The level designer (sounds like that's you) needs to decide whether Tilemaps are worthwhile. Is a strict grid important? Would that save time? Perhaps a tilemap could be useful for the first pass (major grid-based objects) then ornamentation is done manually, but perhaps it's all just manual.

The Hades scene looks so manual that what I might do if wanting something similar is use SpriteRenderers everywhere then build a nice system to load in only what the player is near. The limits the number of objects alive at one time.

 

thanks man that was really helpful!