About this document
An imposter is a simplified representation of a 3D model. Manually creating a simple billboard imposter is a task that can take up to a few hours depending on the complexity of the model. With InstaLOD a multitude of 'Imposter Types' can be created quick and easy.
Although some imposter types have their own settings, most of the settings are identical across the different types.
The 'Padding' determines the distance in world-units between the baked object and the edge of the imposter geometry.
Using 'Gutter Size In Pixels' specifies the minimum distance in pixels between each UV shell created.
The 'Alpha Cutout' allows the removal of expansive-to-render alpha areas by cutting the geometry around the baked object.
Meshes with an 'Alpha Mask' value equal or below the specified value will be considered transparent when baking.
Using the 'Mesh' setting, the mesh operation will only be executed on meshes matching the specified regular expression. Matched meshes are displayed with a filter icon in the outliner.
Left: Padding 0 / Right: Padding 20 Left: Without cutout / Right: Cutout Resolution set to '32'
NOTE: When using models with input transparency/opacity textures, make sure that they are converted to Greyscale textures and not RGB or they will not bake correctly.
InstaLOD features the generation of various different imposter types to fill a huge range of use cases.
The classic billboard imposter is quick and easy to set up. By using the different world-space axis, the user can specify how many imposters per axis to create. Billboard imposters are great for distant objects that will not be seen from up-close or rotated around.
Hybrid Billboard Cloud Imposter
This imposter type creates convincing illusions with parallax when rotating around objects even from up close.
The Hybrid Billboard Cloud Imposter generates a point-cloud within the geometry area and places individual billboard faces within, to create a volume of billboards.
When the mesh is made up of multiple parts, the 'Hybrid Mesh Face Factor' enables part of the mesh to be created as a billboard cloud and the other half to be kept as original optimized geometry. The Face Factor specifies how much of the specified polygon count will end up in the cloudpoly mesh.
Custom Geometry Imposters are used to create even the most exotic imposters.
To use custom geometry as an imposter, the 'Imposter Mesh Suffix' must be added to the custom geometry. By default, the mesh suffix is set to "_imposter" but can be changed to fit into any pipeline.
Keep in mind that Custom Geometry Imposters are generated from the normals of the Custom Geometry outwards.
The 'Axis Aligned Bounding Box Imposter' creates billboards at the bounding-box edge of the selected object. These are created on all axis and are useful when dealing with box-like objects e.g. hedges or buildings.
The additional setting 'Displacement moves the individual sides of the imposter to the center by the specified amount in world units.
A Flipbook imposter is made up of a single billboard that rotates around the pivot point to constantly face the active camera. Depending on the position of the camera in relation to the billboard, the UV-space shifts to show the corresponding texture tile with the correct orientation of the of the object displayed. This creates the illusion of a 3D object using just a single billboard.
The Flipbook Imposter has the additional setting to chose how many 'Flipbook Frames Per Axis' are created.