This section contains the parameters for the "Cleaned" process method. This method simplifies the meshes to make lighter models and give smoother VR experiences.

The simplification is based on two principles:

  • Merge actors: SkyReal has performance issues when handling a number of actors (parts and products) greater than 10000. SkyPrep offers the possibility to merge sub-nodes to reduce the number of actors and increase performance. The drawback of this is that each actor will no longer be selectable individually, but will have to be selected with the other actors with which it has been merged.
  • Remove triangles: A vast amount of triangles can saturate the memory and make the preparation of your CAD file fail, or make the VR experience very slow and unpleasant. This simplification principle uses both defeaturing (remove holes, screws, bevels etc…) and mesh decimation (quadratic edge collapse method).

Merge actors parameters

  • Max actors is the targeted number of the actors after simplification
  • Max hierarchy merge is the maximum depth that can be merged. It avoids having entire branches merged. For simulation with deep trees, this value must be increased to allow the algorithm to reach the max actors target
  • Allow flatten hierarchy allows the destruction of the product tree to remove a big amount of actors

Remove triangles parameters

  • Max triangles is the targeted number of triangles after simplification
  • Allow defeaturing removes holes and screws contained in a cylinder defined by "Max feature diameter" and "Max feature depth"
  • Allow mesh simplification activates the mesh decimation algorithm to reduce the total amount of triangles to the value entered in Max triangles
  • Allow color reduction simplifies and groups vertex colours

Other parameters

  • Level of details (LOD) generates decimated versions of meshes that are loaded depending on the visibility distance
  • UV mapping is the method used to unwrap a mesh on a plan. It is commonly used to apply a texture on a mesh, but its sole purpose in SkyPrep is to make Unreal Engine calculate light rays and reflections faster. Hence why, a sphere projection is used by default, as, even though it does not respect proportions, it allows for quick calculations. UV Atlas is a smart unwrapping method which respects proportions (useful to apply textures afterwards), however it is long to process and quite unstable.
  • Physical envelope lets you decide you want to calculate collisions
  • Remove duplicate determines if several instances of a part are at the same position and leaves only one