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Why does the volume of FBX file increase after importing unity2021 and building?

Discussion in 'General Discussion' started by mike2022unity, May 9, 2023.

  1. mike2022unity

    mike2022unity

    Joined:
    Nov 29, 2022
    Posts:
    7
    Unity2021 Android and webgl

    The FBX source file is only 14M, but after build it becomes 45M





    Online is very anxious to thank you
     
  2. neginfinity

    neginfinity

    Joined:
    Jan 27, 2013
    Posts:
    13,496
    Unity does not store models as fbx. It converts them to internal format. Unity also requires additional per-vertex data in a model, and if it is not present in fbx, it will be computed, and that can cause fbx size to grow.

    Basically, normally each model vertex will store position (3 floats), normal (3 floats), uv coordinates (2 floats), tangent (3 floats), binormal (3 floats), and optionally lightmap coordinates (2 floats). If your model only comes with position/normal/uv, its size can easily double.
     
    Ryiah, CodeSmile and mike2022unity like this.
  3. Noisecrime

    Noisecrime

    Joined:
    Apr 7, 2010
    Posts:
    2,035
    Does the fox have embedded textures? That could inflate the size when imported into Unity, which depending on image format and type of image data in the texture could balloon the file size considerably for large dimension textures.

    Animation can also inflate the size, depending on the import settings.