How can I quickly generate / create a large city without modeling it all by hand?

Question

I am trying to create an urban open-world environment in Blender that would be about one square kilometre in size. To avoid having to model hundred of individual buildings, I am looking for a way to quickly generate them procedurally - but there should be an element of variety (i.e. preferably not a grid-like fashion).

Also, it is possible to generate other features such as pipes, windows and ledges on the exterior of the buildings?

I have the feeling that the way about this is using Python scripts, but I am unsure as to the specific details required.

Any help would be appreciated.

Answer 1

City Generation

Suicidator "City Generator" (SCG)
This is a very robust Blender addon that can create amazingly detailed & complex cities:

• Generate random terrains (including bodies of water) for your city, or use your own bump maps to create the landscape of your choice

• SCG automatically generates all the textures for your buildings, roads, grass, water, etc.
  (NOTE: Currently, SCG only generates textures in Blender Internal, not yet for Cycles)

• Specify if it's day or night in your city

  

  

  

  

  NOTE: As of City Generator v0.5.7, textures will ONLY be generated in Blender Render, NOT yet in Cycles. So, make sure you are in Blender Render BEFORE you click the Build City button:

  

  You can read the City Generator online manual on their website and see many more examples.

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NOTE: There is another addon listed on the Blender Wiki called "City Block Generator". However, this addon only works with Blender versions 2.4x - 2.5x, so it's not an option for any versions later than 2.5

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Adding Special Building Details for Close-Up Shots

If you ever want to have a close-up shot of a particular part of your city and want to add specific building details, you can use these add-ons:

• Block Wall Builder: Block Wall Builder allows you to build your own custom walls. It has a lot of functionality, including the ability to add holes in the wall for windows, doors, etc.:

  

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• Window Generator 2: Add custom windows. Download it here and read more about it here. Here are some samples:

  

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• Jamb Generator: This addon from Seyit Ali YAPRAKCI makes custom door frames/jambs:

  

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• Archimesh: Archimesh gives you the ability to add great detail to your buildings: add rooms, house structure (walls), doors (one and two leafs), columns, stairs (strait and curved), tile roofs, cabinets, shelves, windows, books, lamps, curtains, etc. It can also UV unwrap rooms! You can download it here and you can get more information on how to use it here. Here is a sample of the cabinets with shelves:

  

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• Balcony Generator: This addon, also from Seyit Ali YAPRAKCI makes balconies:

  

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• Chimneys: This addon, again from Seyit Ali YAPRAKCI, makes chimneys:

  

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• Flat Board Generator: This addon allows you to make hardwood floors:

  

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• Add Pipe Joint: You can read about this built-in addon here and here are some sample joints:

  

  NOTE: If you want to extrude pipes from these joints, see this question and answer for details on how to do it.

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Add Snow and Icicles

If it's winter in your city, you can add piles of snow to your meshes with the technique described here and with the Icicle Generator you can add icicles:

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Adding Terrain for your City

If you don't want your city to be on flat ground and aren't using Suicidator City Generator, you can make unique landscapes easily with the built-in addon ANT Landscape:

The Blender manual describes how to use this built-in addon.

NOTE: Previously, these landscapes all had the normals flipped the wrong way, which makes the underside of the mesh be considered the top. This has been fixed in an update, but if you have an older version and you're finding this is a problem for you, you can fix it simply by flipping all the normals:

• Select landscape → TAB → select all (A) → W → Flip Normals

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Add Trees

"Sapling" is a built-in addon that allows you to make trees:

This addon is amazingly robust, capable of making a huge array of different kinds of trees and bushes:

This addon is much easier to use if you watch a tutorial about it.

For more detailed information about making trees, see this page.

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Add Scattered Debris, Litter or Plants

If you want to have litter around your city, or debris & weeds in an abandoned lot, you can do that using a Hair Particle System, which you can learn how to make on this page.

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Add Rocks

The Add Rocks addon allows you to quickly add randomly generated mesh rocks, thus making it much quicker to add detail & practicality to your outdoor settings, urban or otherwise. Here you can read about & download this addon (note: the Add Rock addon is part of the bundle described in that post.) Here are some examples of the 5 rock presets:

For lots more details on making Add Rocks, see this page.

NOTE: One thing to be aware of is that each rock has many modifiers on it, and these slow down render time. See this page (at the bottom) to get details on how to solve this issue.

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Add Ivy

Blender's built-in "Ivy Gen" addon is very good at creating realistic looking ivy:

Answer 2

In addition to the other great answers here, I would add Gleb Alexandrov's tutorial video: How to Create a City, Covered With Fog. Regardless of whether you opt to add the fog, this is a very helpful (and quick) tutorial for creating cities.

He uses the Open Street Map add-on to generate the layout, so the angles of the buildings look very natural because they are based on real cities. And his texturing approach is brilliant.

Some screen shots from the tutorial:

Answer 3

If you need to work with Cycles, there is the BlenderGuru tutorial on building cities. It uses a particle system with one particle (from a group of objects) per face of your street plan. With a group of 30 to 40 low-poly building models you can build a pretty substantial city.

In this case I did not need streets so I packed my buildings tight but the tutorial includes a technique to create them. I used three particle systems one for the center with a dozen different models, another for the hi-rises with another set of models and a third system for the outlying lower buildings.