Giant Monster game - Build full scale or miniature?

Hey anyone out there who might have any perspective on this.

I am early on working on a game where the players play as giant monsters/mechs and destroy buildings and whatnot. They will start grow over time all the way to about 100meters tall. I figured building the game out at 1:1 scale would be big, sure, but probably better for asset use and stuff.

My concern is that building stuff for gameplay that big feels a little wrong. Distances and forces and masses and speeds feel pretty wildly huge and not the most convenient to work with. Additionally, certain render distances for things like shadows or fog might be impractical. And what about, traces and collision zones and calculation at that scale? Do I risk bogging down the engine? (IE Pawnsensing at 25-50000 units out for every ai, or half kilometer line traces on everything) would this cause me issues? Are there things im not thinking of?

So my question is am i going to be causing myself a lot of headaches building giant characters and enviroments at 1:1 scale, or should I build the game in miniature? As an example: A 10meter building is now 1 meter tall. 100 meter monster is now 10 meters tall. My ~3km map would then be 300m across. Would this be better, or is the 1:1 scale in question not a concern in ue5?

It would be wonderful if anyone has any wisdom to offer! Thank you!

Hey @Lexinator117!

More than likely, your ideal route would be to use smoke and mirrors to give the illusion of large and build smaller. Not only should it address the concerns you laid out, it should also keep your map size down which should help long term for how much drain you will have on your resources.

Base any decision on floating point precision limits.

5000 verts compressed in 1cm is never going to work.
5000 vertes compressed in 1m could.

Thank you quetzal, and most host- i am keeping this thread open a little longer in case anyone else has any further insights.

You must forgive my lack of knowledge on exactly how float calculations work- but youre telling me there is also a pretty hard limit on how small you can go? That makes sense. Based on both your advice i think i need to shrink it. The question now for engine health is how small to go. A scale down by a factor of 2, 5, or 10.

If i go down 10x smaller, the smallest the player’s character would ever really get would be 1-1.5m (down from 10-15).

The things they can interact with in the scene though might be much smaller. Busses, trees, tanks and cars would be a meter or smaller. Humans (likely very simple models and ai) running around would be only about 18cm. Anything smaller than that would be props that would really on serve to be destroyed on overlap, or maybe be knocked around with simple collision.

I dont THINK simple interactables on that scale that would be a huge issue. As far as most games go things 5-20cm are like tennis balls to cups to bottles. Those usually work “decent enough” for traces and collision checks but do have issues occasionally.

Or, perhaps, do you think there is a goldilocks zone at about 5x smaller. Default smallest player would be about 2m. Humans would be 35cm, Smallest interactables and props would be about 15cm. 3km map would be about 600m wide.

I would love to hear what you think of those options / considerations?

As one additional more straight forward question: it is possible to adjust level/project gravity scale, correct? That way i can make the scale FEEL correct?

You have to consider what distance on screen something is visible from.
And the resolution of it at each distance.

Placing the same amount of vertex as the old mannequin in a skeletal mesh of a human that’s 18cm tall means that around 30% of the verts are useless or just about.
Im guessing this, you should try it.

If you are modeling things, it gets a little easier. Just keep your units as Cm and avoid placing vertex in the middle of Cm values.

Now though, obviously when moving and such, the engine doesn’t take that into account. A vertex can be mobing by a micromiter or whatever value just based on character location.

So the questions you need to answe are:
Will the mesh deform and look OK from the viewpoint of the player?

What is the maximum distance from the player where a deforming mesh starts to loose enough precision to look wierd?

Will using LODs with less resolution as these distances help?

Etc.

I think you’d have an easier time making humans into hobbits. Around 1m tall.
But that’s just a guess based on making hobbit like creatures in the past.

Note that if you need to add flees/ticks and generally animals which are below 1cm you wouldn’t be able to see them (in reality you almost can’t in 1:1 scale either, I had to scale mosquitos to x2).
So try and consider everything you wish to add to the game before testing for what scale and distances you are bound by.