Generating Impostors with Impostors Creator
Impostors Creator tool is used to create impostors that are rendered instead of real objects at large distances. Impostors are usually used to optimize performance if you use mesh clutters: at a certain distance from the camera, they are rendered instead of the real geometry.
The Impostors Creator tool allows generating impostors for a single object or for objects baked into a mesh clutter:
- For a single mesh object (Static Mesh, Dynamic Mesh, Skinned Mesh), the billboards-based impostor is generated.
- For the elements of the Mesh Clutter, the impostors based on the Grass object are created.
The tool also provides special settings for generating impostors for vegetation. Impostor textures generated for vegetation ensure that when rotating a camera around any tree, its trunk will exactly match its geometry original regardless of the tree shape complexity.
See Also#
- The articles on Grass and Billboards objects.
- The articles on grass_impostor_base and billboards_impostor_base materials.
- The part of the Content Optimization video tutorial dedicated to generating impostors.
Impostors Creator Settings#
The Impostors Creator tool has the settings described below.
Textures#
The tool allows generating the following textures for impostors:
The following pictures show the difference between impostors, which textures have been baked in different modes:
For each texture, you can choose the format:
- .tga
- .png
- .dds
- .psd
All textures are imported with the Unchanged flag disabled. It means that runtimes are created for the generated impostor textures.
Settings#
Resolution | The size of the grabbed texture. | ||||
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Supersampling | The number of samples per pixel used for supersampling. The grabbed image is rendered in higher resolution (N times bigger) and than down-sampled to the specified size. The higher the value, the more reduced aliasing is. You can specify any of the available values for textures of any resolution. For example, for 4K textures you can specify 4x or even 8x supersampling. The option is available even for 8K textures. Available values: 1x, 2x, 4x, 8x. | ||||
Aspect | Aspect ratio (width/height) of the grabbed images. The aspect affects the size of the impostor texture cell that stores the grabbed frame. For example:
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Phi | The number of frames to be grabbed into the impostor texture when the camera rotates horizontally around the object (i.e. left or right). Available values: 4, 8, 16, 32, 64.
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Theta | The number of frames to be grabbed into the impostor texture when the camera rotates vertically around the object (i.e. upward or downward). Available values: 1, 2, 4, 8, 16.
When selected value is equal to 1, Lerp Mode for the impostor material (billboards_impostor_base and grass_impostor_base) shall be set to Horizontal Only. |
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Padding | Texture padding. The recommended value is 256. |