Optimization guidelines

The frame rate must be optimal for real-time 3D applications.

You can reduce the frame rate of CAD models to less than 60 frames per second. CAD models may have complex topologies, which translates into a high polygon count, but may also have many parts and materials, which translates into many draw calls.

Reduce the polygon count

Decimate your model

The most common way to reduce the polygon count is to decimate meshes. You can decimate meshes at import.

Decimation works up to a certain limit, after which geometries are too damaged. If the polygon count is still too high after import, you can apply other strategies, depending on your model and your needs.

Delete occluded geometries

You can delete inside geometries.

This processing proves particularly efficient on these models:

Models that have internal parts
Models that have been designed as solids
Models that have been designed using CAD software

Retopologize meshes to create a rough mesh

You can bake the normals map to mimic slight surface changes while reducing the polygon count.

You can retopologize meshes for levels of detail.

Reduce the number of draw calls

A draw call is a command that is sent by the CPU to the GPU to draw something on screen. Because the CPU and the GPU have different purposes, they only briefly communicate during the rendering of a single frame.

The more time is spent on draw calls, the less time is left for the GPU to execute these commands during the remaining frame time. A good strategy is to reduce the number of draw calls or to group commands into a single batch command.

We recommend that you simplify the product structure and reduce the number of submeshes. For example, you can use these features:

Combine meshes
Retopologize meshes

Merging is the easiest way to reduce the number of draw calls, but has two disadvantages:

Merging flattens the hierarchy. You can choose to merge models at specific levels, to merge only the subassemblies that represent a set.
Merging destroys the instances of a same object. If your assembly mainly consists of many instances, merging might not be greatly beneficial.

You can retopologize meshes for these purposes: