Manage Large Scenes in 3ds Max

Figure 1: Housing development in 3ds Max

Scene sizes are growing and the demand to show more—and show it more realistically—evolves constantly. We are expected to push the limits, to reach an idea, into someone's imagination, and build it from scratch, one triangle at a time. We mold it, move it, animate it, analyze it, and push the very cores of our computers and its ability to process in order to create characters that topple buildings and toss tanks for big screens, create sustainable developments, help with advancements in technology, science, and more. The ability to manage scenes with these expectations can be the key to their success.

First, our duty is to utilize every bit of processing power, RAM, and space we have available to develop the best product possible. This starts with poly count for every single object we have placed in our scene, whether it's a blade of grass or a skyscraper. Simply put, the more polygons in a scene the more our computers have to process, resulting in higher render times and lag during workflow.  Fortunately 3ds Max® provides some tools to help reduce the poly count of objects in our scenes.  Shown in Figure 1 is a model with an exceptionally high poly count.

Figure 2: Gear system for watch—203,150 Polys; 134,967 Verts

Figure 3 below shows the same model after running 3ds Max's Optimize Modifier.

Figure 3: Gear system for watch—91,456 Polys; 79,120 Verts

As you can see there's little difference between the edge-free renders.

Using the modifier is simple: select the modifier and change the Face and Edge Thresh values.

Figure 4: 3ds Max Optimize Modifier

If you've already developed your scene and simply want to scan it for areas you can optimize, this is simple as well. Choose the Select by Name tool (number 1 in Figure 5) and add Faces to the columns available to sort by (number 2 in Figure 5).

Figure 5: 3ds Max Select by Scene tool

Second, keep in mind the distance from which your object appears. The farther the distance from your camera, the more likely it is that you can exclude particular details such as fillets, bevels, chamfers, or even entire faces since many of them may not be visible to the eye in the final product.

Third, in order to effectively manage a complex scene it's necessary to use proxy objects. Proxy objects are low-poly representations of high-poly models in a scene, based on a single source file. These can be trees, blades of grass, cars, people, or whatever you decide.  They allow us to place hundreds of these objects using various tools such as linear or random arrays in a matter of a few minutes, while populating our scenes with only low-poly representations of what they actually are. This frees up memory, allowing us to work more quickly within our scene. When it comes time to produce the final result, the render will process the high-poly version to produce the best possible render.

Tip: when creating a model that will act as a proxy object, it's best to produce it in its own scene; using your larger (parent) scene can cause problems.

Figure 6: City scene with proxy trees

Fourth, use xrefs.  Xrefs allow us to build incredibly complex scenes by dividing them into multiple files. In high-production environments this is also helpful by allowing members of multiple teams to work on a specific scene. For example, when working on a large community development, one member can work on the streetscape while another works on the homes or traffic features.

Finally, planning for predetermined camera angles allows us to minimize poly count by focusing our attention on details seen in specific frames, allowing us to ignore or even delete objects that we wouldn’t see. Spend time setting up scenes early in the production process to avoid a lot of unnecessary work. 

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