Smoothing groups

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The cylinder on the left is not smoothed.
The cylinder in the middle is smoothed with the default lightmap scale of 16.
The cylinder on the right is smoothed with a lightmap scale of 8.

Vertex Smoothing simply uses Vertex normals (vectors) as if they were Surface normals to generate a kind of pseudo-subdivision surface for the Lighting shader to work with.

When a number of adjacent surfaces are assigned to the same Smoothing group, the Rendering Engine will "soften" the light and shadow across each vertex or edge shared by the group. This makes the geometry seem smoother when viewed from most angles. It does not soften the profile or silhouette of the object.


  • Brush geometry must be manually assigned to a Smoothing Group in Hammer. Model geometry smoothing data is configured in the model editor before SMD export.
    Confirm:Brush smoothing groups may not include Model geometry, and vice versa.

Auto Smoothing

  • Some games, VBSP will auto smooth angles 45 degrees and under.
    Confirm:Any games other than CSGO?
Brushes of 45 degrees or less will be auto smoothed.

See Also