Create an city with Sketchup models

Hello all,
I want to create a city with existing sketchup models as you can see in picture bellow.

I just want to walk nothing more.
What are the steps to do this?I want to have minimum 50 FPS.
Thanks

Depending how complex each building is, I would export larger individual buildings, or complex of buildings as separate OBJ files.

Make top down render and save it as image.

In Unity place that image on a plane, in top down view.
Import obj models.
Place models into respective places.
Import basics walking script.
You may want to look for it in asset store. There are free ones.

Optionally, you may want to add basics colliders to objects, so you can not walk them through.

@Antypodish
Hello
The models looks like this,are very complex with hd texture.
I am plan to insert 100 or more.It is a hard work?
Is hard to optimize this?

This model is considered very low poly.
In Unity you could generate more optimized version for LODs.
But I wouldn’t worry about it.
You may consider implementing camera culling instead.
Specially, if you want just walk the city, on the ground level.
Also, performance and requirements depends on the target hardware, on which such scene need to run.

You need to consider importing model with textures.
But you may want to do research on your own on that.
Here is an example search engine query.

You may also want to search, if there is some automation process, for exporting multiple models.

@Antypodish
Thanks for the answer. I already import the model in Unity with texture and material.
The problem is i have only 20 FPS with one building.
I have a pretty good PC,Gpu Nvidia 2070 Super,processor Ryzen7 3700x, 32 GB of ram and 2 tera SSD.

That shouldn’t be happening. Can you show us the profiler window?

The models are complex like Coloseum.
I think there are to many faces.
Can be done something with this kind of models?
How can i optimize if i want to insert more than 50 models like this?
I can get 60 FPS?

Generate LODs

If the roof tiles are components, you can make a simpler one inside, then add a LODGroup in unity to switch between them. Every component will require this.

50+ coloseums ?, not going to happen. Do you realize the count of verts/tris for this model?. Look at your export results…1,155,999 faces, with 37 materials. I dare you to put 3 of those in your scene, fps/ms will slow to a crawl.

To optimize that asset, you would have to LOD, decimate (reduce tris/verts), atlas/combine textures, and alot more to get it even close to useable. Ever hear the phrase “bit off more than i can chew”?. It applies… Your job is to prove me wrong…

How close are you able to view the model in game? If you’re looking top-down like that, you should retopologize the model. You could probably make a model that will look almost identical with just a few hundred vertices, one texture, and one normal map.

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OP mentioned walking.
So that means streat view angle. Hence very up close.

If you’re going around in a close-up perspective (like first-person or something) there are a lot of other things you can do. For example, if the player is walking around at ground level then you can make the upper parts of the building significantly less detailed than the lower parts. The player is not going to be able to look at the high parts up-close unless they can fly.

Also you can make the inside and outside of the buildings separate meshes. You can’t see the outside from the inside and you can’t see the inside from the outside, so there’s no need to ever render both. In fact, if you’re inside the Colosseum, you won’t be able to see any of the other 49 buildings at all, so no need to render them.

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Im not sure using Sketchup models is the best choice, as no LODs, too many materials, and too many faces. But you can LOD them, reduce textures, and reduce tris/verts. Another thing that helps is camera settings, how far the camera can see and render.

Theres assets on the store to do these things (auto LOD, atlas makers, and reducers for tris/verts), some are free and some are not. Have you tried looking around other modeling sites to see if you can find lower poly buildings, or buildings better suited for your project?. Ill have a look around and see if i can find anything…

Example: https://assetstore.unity.com/packages/3d/environments/historic/ancient-colosseum-01-184861 Check this one out, 4 textures, and only 6519 poly, and it looks good. Theres a ton of roman era buildings on the asset store, and alot more on other sites…

Also, maybe Unreal and nanite like tech could help to tackle the problem?

Sketchup is absolutely not made for this sort of realtime 3d stuff. At minimum you have to completely retopologise models. Try sticking them through something like Simplygon and see what comes out the other end as a quick solution. But really you need an artist to retopo these to make them vaguely usable, as what you have is effectively CAD amount of data compared to realtime 3D amount of data.

Alternatively, you could stick these into unreal using Nanite with little difficulty (just make sure NOT to use Lumen as itll kill your framerate)

They are very accurate looking models, at least the Colosseum which other assets are no comparison to. A fun project!
But yeah Unity does not give you all the tools to easily optimise such models for real-time and there is much to learn without a technical artist around. The unity mobile (because heavy optimisation needed) e-books or the graphics forum are resources that will help. Poly reduction, Lods, material count reduction, check overdraw etc. etc.