Dilate

Dilate grows a solid outward by at least the radius you set, never less. Flat faces move outward. Outside edges and corners become rounded, holes become smaller, and nearby features can join.

An L-shaped solid after dilate

How to Use

  1. Select a solid part
  2. Click Dilate in the Round & Offset group of the toolbar
  3. Set Radius to the smallest distance to grow
  4. Wait for the operation to finish; use Cancel in the task area to keep the previous result

On a detailed part, MatterCAD builds fast by default. Every surface still moves at least the radius, but inside corners that should stay sharp can come out slightly rounded, and a note in the panel says so. For perfectly sharp edges, check Exact at the top of the panel; it is slower, and on a large part it can take minutes. Simple parts are always built exactly, so the checkbox doesn’t show for them.

With Exact checked, dragging the Radius slider shows a quick, see-through preview, and a Preview row appears in the task area. Let go to build the exact result; it replaces the preview, with a progress bar and the time left. Grab the slider again to stop that build and return to the preview.

Parameters

  • Radius - The least distance surfaces move outward (default: 1 mm). Must be greater than zero. Some faces can move a little further, never less
  • Exact - Shown only on detailed parts (256 triangles or more). Check it for the precise result with perfectly sharp edges; it is slower. Unchecked, the part builds in seconds
  • Segments - Only used by exact builds. The detail of the rounding ball (default: 16). More segments produce finer curves and bring the result closer to exactly the radius set, but take longer, especially on parts with pockets or notches

Tips

  • This changes the whole part’s dimensions. To round edges while broadly preserving the original dimensions, use one of the Round operations below
  • Radius is measured in the source part’s own coordinates. Non-uniform scaling applied afterward also stretches the rounding
  • These operations require a solid. Use Inflate Path to grow or shrink a 2D path