Modeling Modular Game Assets

Modeling Modular Game Assets

This course teaches how to build modular assets for lego-style building of a game level. It’s focused on both modeling and texturing of low-poly assets for exporting to Unity.


Watch this brief video to see what the course is all about before diving in!


With Blender, we will build our game assets with as few polygons as possible. We will also build them to snap together like pieces in a puzzle.

Texture Creation

Using Blender's texture paint mode and Photoshop, this chapter centers on the process of creating texture maps for use in Unity's PBR shading system.

Creating “Portalethium”

Portalethium is a sci-fi game that the CG Cookie crew developed for the purpose of A) playing and B) learning. It’s a tower defense game that was built from the ground up using Blender for 3D asset creation and Unity for game development.

If you haven’t played the game yet, please play it here!

Modular modeling madness


We decided that a modular environment was the best way to approach building the game level. Modularity works like Lego’s, where pre-built pieces are interchangeable and extensible. This allows for a flexible level-design process that’s perfect for iteration. It’s also much easier to build a collection of interchangeable pieces than it is to build and texture an entire, un-modular level.

What You’ll Learn


Everything about asset creation for games is accomplished with resource efficiency in mind. This means using fewer polygons for models, overlapping UVs where able, and getting the most bang-for-our-buck out of our textures.

  • Modeling for modularity: These assets are sci-fi in genre and hard-surface in shape. Therefore the modeling approach is polygon modeling.
  • Efficient UV layout: To keep our assets as resource efficient as possible, we’re going to combine all our models’ UVs into one texture space. Also we’ll overlap UVs where possible to accomplish texture symmetry, as well as overlap UV’s of duplicate pieces of geometry so they all share the same texture info.
  • Texture Painting: Our textures are generated using an “evolutionary” approach where portions of maps are painted or baked with Blender and then layered together in Photoshop to create final versions. We will also be painting textures to take advantage of Unity’s PBR shading system.
  • Exporting & Importing: Portalethium is going to be built with Unity, so I’ll show you how to export our assets from Blender and import into Unity. I’ll also cover the workflow of updating our assets between the programs as we progress through the creation process.

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Lesson Questions and Answers

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  • Replies: 0

    Hi Kent,
    Thx for this great course, it’s a wonderful job as always. I just want to let you know something :
    I’ve noticed that each time you want to set the origin of an object, you either use the “Shift + Ctrl + Alt + C” shortcut or you go down the “Object” menu of the 3D view.
    I just want to make sure that you know that there is a quick access to that tool in the toolbar region under the “Edit” tab (you’ll find a dropdown menu called “Set Origin”).
    You may already know about this but surprisingly, I’ve never seen you use it although I find it much easier and quicker than the other two methods. 😉

    1 week ago

  • Replies: 1

    What was updated in the course?

    3 weeks ago

    • Replies: 0

      Nothing substantial. It’s a bit of a quirk with our current site (of which we’re working on a massive new version). So I may have fixed a typo in the About section and upon saving it still records that as an update. Sorry about that.

      3 weeks ago

  • Replies: 2

    Hi, now I’ve watched all the lessons I can see a heavy dependency on having access to the full version of Photoshop. The Metallic texture sections in particular rely on some features and working knowledge of PS that were assumed in the course i.e. they were covered very quickly without really explaining what the final image file contains. How feasible is it to use PS Element, GIMP or other software to achieve similar results?

    1 month ago

    • Replies: 0

      I agree as well. I know Photoshop is great, but not all of us can afford to spend $120 a year just for Photoshop. I can get SketchBook Pro for $30 a year and I enjoy that much more than Photoshop.

      1 month ago

    • Replies: 4

      If you’re familiar with GIMP than it should be pretty easy to mimic the techniques done with PS in this course. I didn’t use anything special to PS like filters or unique tools, it’s all just basic image manipulation functions available in any competent photo manipulator

      Question: If we taught GIMP or Krita at CGC do you think that would be a worthwhile choice? The danger is that we have a bunch of users learning strictly Photoshop from Tim and to teach GIMP/Krita on the Blender side, we create a disconnect between the users.

      1 month ago

      • Thanks Kent. I’m not suggesting that you teach GIMP or Krita. My opinion would be that it would certainly be of interest but that wasn’t point I was trying to make. You are obviously very competent int eh use of PS. For those of us that don’t use it, wha

        1 month ago

      • (sorry the web site truncated my reply) For those of us that don’t use, or have access to the full version of PS, what happened was a rapid fire mystical black magic moment where you achieved a result but at a pace that was different from the rest of the lesson. The objective wasn’t clear until AFTER you’d done everything. The process still isn’t clear in my mind because I’m not familiar with layers and groups and the operators and functions that can be applied to them. This makes it difficult to translate to other software tools that might be capable of achieving the same result. I’ll get chance to review this in a day or two and hopefully I’ll make steps forward in my understanding. Ultimately this (PS) is a hole in my experience and education so it is bound to be more difficult to get to grips with. However, for me to achieve the results you did I need to move that segment of the pipeline to another tool so understanding the process was more important than specific PS keystrokes and operations. That aside, thanks for a great course. I thoroughly enjoyed it and learned a lot.

        1 month ago

      • I understand your frustration @rubicon_paul and my sympathy is for it. We categorize course difficulty as either beginner (one dot), intermediate (two dots), or advanced (3 dots) and since this is an intermediate course, the expectation is that nothing taught is for beginners. So like you said, if PS is a hole in your education, then those parts of the course is certainly going to be difficult.

        But still, we hate hearing disappointment with our courses or parts of them. So what do you think I could do better in the future to best teach the broader [intermediate] audience, including you and those that aren’t you?

        1 month ago

      • Hi Kent,

        the photoshop stuff was black magic stuff for me too :-) But I just started with all the stuff so it is not much relevant. In my opionion it would be good to use PS and any other open source tool like GIMP or Krita to show the process. The idea is that Blender is also opensource. So when you start doing stuff you simply try to too choose all tools as opensource. I personaly choose Krita as for me is much nicer looking than GIMP. I used gimp before, but than i found Krita :-)

        3 weeks ago