Content Optimization

Use common sense and personal experience to decide on what values should be set for various objects in your scene: for example, small objects are not discernible at a big distance, why setting an infinite visibility for them. Based on this you can:

• Configure visibility distance for all objects globally or individually.
• Configure levels of detail to simplify a model at a distance, thus reducing the rendered number of triangles.
• Consider using occlusion culling to avoid rendering of objects that are hidden behind a bigger object.

Assess the approach that was used at creating the models and consider if they can be optimized for a better performance when rendered in real time:

• Don't create one inseparable mesh for a big model (such as a building) uniting a great number of elements (doors, poles, stairs, etc.), otherwise you won't be able to use various optimization tools available in the engine (such as clusters and clutters that can speed up rendering of numerous identical parts and reduce performance costs).
• Use impostors wherever applicable (background/distant vegetation and some other distant objects quite often don't require geometry, so you can just replace the model with a flat square photo of the model — just two triangles, it's definitely less than any model that you have).
• Make sure that the potential of a material is used to the full extent: for example, small bumps and curves may be implemented not as the object geometry, but using the normal map (displacement sample). Check Art Samples to find more ideas.
• Inspect the content in your scene carefully, you might have added objects that you don't use (hidden somewhere inside a building or underneath the scene). Remove them, otherwise they'll also affect performance.

The number of triangles rendered for shadows also can be significally reduced in a number of ways:

• A shadow is a projection of a model that's why a shadow cast by a model contains the same number of triangles as the model. But any shadow definitely doesn't require so many details. Use the most simplified LOD to cast shadows: enable shadow casting by that LOD and disable it for all other LODs.
• Shadows are not necessarily required in the distance. Configure the shadows visibility distance.
• Disable shadows cast by objects and enable screen-space shadows to check if they will be enough for your project. If you are dissatisfied by screen-space shadows at a short range, consider using them starting from a certain distance and configure shadow casting for all objects correspondingly.
• Use static shadows for objects that won't change their position, and the light source won't also change its position.
• Use shadow settings sparingly (such as Filter noise and Penumbra noise)

Dynamic lights affect performance, therefore develop a habit of replacing them with static lights or even faking them wherever possible. This is primarily applicable in indoor scenes and scenes with unchanging light conditions. UNIGINE has a set of tools and approaches for that:

• Voxel Probes contain indirect light baked from static light sources, so that an object moving inside the probe is shaded appropriately.
• Billboards, Volumetric Objects may represent a light source visually, but without providing any actual illumination.
• Static Lighting may be used for night scenes. You can find a simplified example for that in the Lighting section of Art Samples.
• Lightmaps store brightness and reflected color of lit surfaces and can be used in static scenes.