First calculate "sea level" (pokemon uses 1 tile, but if you are using 3D isometrics then I can't assume you'll have a height of "1" at all times)

Next, in your draw step - include a low opacity vertically flipped draw of your sprite at a position equally below sea level as your character is currently above sea level.

That's the bare basics: There are more nuanced ways of doing this too such as drawing ALL objects onto a surface that's sole purpose is to be rendered under water effects

Even without the depth issue I'm afraid just flipping vertically isn't enough for isometric geometry, since the reflection is showing you a face of the cube you can't see in the non-reflected version and vice versa. I'll have to make a reflected sprite for every block type I want to reflect...!

Might as well mention that in my current attempt I'm using a "deco_water" object to draw reflected versions of all affected sprites onto a surface, apply a shader, then draw the surface at a high depth. In theory the only issue is that the reflected sprites' depths are negatives of what they should be

For reference: https://cdn.discordapp.com/attachments/664869553976901657/934149884691488768/unknown.png

there's no need for such advanced trickery... just draw your entire gamefield as a surface and render it upside down using everything that isn't water as a mask.

Originally posted by Blind:

there's no need for such advanced trickery... just draw your entire gamefield as a surface and render it upside down using everything that isn't water as a mask.

Won't that make it so that something northwest of the character (on the same height) will appear southwest of the character in the reflection? (Remember, this is an isometric game, not a 2D sidescroller, so the game world isn't "flat".)

Originally posted by supware:

- Might as well mention that in my current attempt I'm using a "deco_water" object to draw reflected versions of all affected sprites onto a surface, apply a shader, then draw the surface at a high depth. In theory the only issue is that the reflected sprites' depths are negatives of what they should be -

Can you "sort" these objects while drawing them? If so, if we say that the depth of a non-reflected object is "-y - z", then the depth of a reflected object should be "-y + z" (not "+y + z" nor "+y - z"), I think.

It's supposed to appear southwest, reflections are cast by the sun - not the camera. (unless i'm misunderstanding you.

I still think the best option will be with masking

Originally posted by Blind:

It's supposed to appear southwest, -

See this image: https://imgur.com/j6X13tW
Here, you're suggesting the middle "Vertically-flipped scene reflection", which doesn't look right compared to the "Proper scene reflection" on the right. In the latter, the green orb is northwest of the blue orb in the original scene and in the reflection.

The middle option would work in a 2D sidescroller, but not in anything resembling 3D.

Originally posted by Blind:

- reflections are cast by the sun - not the camera. -

What do you mean?

ok, i simply misunderstood what you were doing.

In this case just extend all your terrain manually (duplication, just like in 3D) and render that above your reflection object so they are obscured bu the terrain, and then render your primary object. (this is a brute force fast way and will run into problems if you have enough height that an object may appear into a different "lake")

Render order would be (all object reflections), (all terrain), (all reflectable objects)

You want something like, This, right? https://lettier.github.io/3d-game-shaders-for-beginners/screen-space-reflection.html

That looks like the same effect I'm after yeah. Ordering them somehow seems like the most sensible idea, but I still don't see exactly how it'd work (you'd have to order all reflectable objects by depth I guess...?)
And here's an image of my attempt where the character is facing the water;[cdn.discordapp.com] however I end up ordering the reflections I don't see a way around having to make new sprites for everything like how you can only see his face in the reflection

(I should probably clarify if it's not obvious that I'm not using any 3D stuff, the game is just hexagons and circles)

Yes, you'd have to draw reflections for the "underside" of any object being reflected. If you have some isometric dice jumping over the water and the 1 dot is on top, its reflection should cast the 6 dots.

So I guess it boils down to "how do I efficiently make a ds_list/array of all instances ordered by depth"... I'll take a look at this today