Removing Polygon Mesh Components

There are several different ways to remove polygon mesh components:

Delete Components removes the selected components and any other components that share them, leaving nothing in their place. See the next section, Deleting Polygon Mesh Components.
Collapse Components deletes the selected components, then reconnects any other components that shared them. See Collapsing Polygon Mesh Components.
Dissolve Components deletes the selected components and fills the resulting gap with new polygons. See Dissolving Components.
Dissolve and Clean Adjacent Vertices dissolves the selected components (as described above) and also removes any points that are shared by only two edges as a result of dissolving components. See Dissolving Components and Cleaning Vertices.

All of these options are available from the Modify Poly. Mesh menu on the Model toolbar, as well as from the context menu that appears when you right-click on an object in a 3D view while components are selected.

When components are selected, pressing Delete performs different actions:

Points and edges are dissolved and adjacent vertices are cleaned.
Polygons are deleted.

Deleting Polygon Mesh Components

You can delete polygons, edges, and vertices using Alt+Delete. Deleting removes polygons, leaving empty holes.

When vertices are deleted, any edges and polygons that share those vertices are also deleted (below).

Deleting selected vertex
When edges are deleted, any polygons that share those edges are also deleted (below).

Deleting selected edge
When polygons are deleted, any edges and vertices that are no longer attached to a polygon are also deleted (below).

Deleting selected polygons

To delete polygon mesh components

Select some vertices, edges, or polygons on a polygon mesh object.
Press Alt+Delete or choose Modify Poly. Mesh Delete Components from the Model toolbar.

For polygons, you can also press Delete.

Collapsing Polygon Mesh Components

You can remove polygons, edges, and vertices by collapsing them using Ctrl+Delete. The components are removed and remaining components are reconnected, creating no new holes.

When a vertex is collapsed, it is removed along with any edges that share it. The other vertices that were connected to those edges are joined in a loop by new edges (below).

Collapsing selected vertex
When an edge is collapsed, it is removed along with its two endpoints. The other vertices that were connected to those edges are all joined to a new vertex at the midpoint of the collapsed edge. The effect is as if the original edge was scaled to zero (below).

Collapsing selected edge

If you collapse just one edge of a double edge, the selected edge is removed. The vertex at the end of one of the "dangling" edges is removed and that edge is reconnected to the other "dangling" vertex, which is moved to the midpoint. This affects other polygons adjacent to the double edge.

Collapsing one edge in a double edge
When a polygon is collapsed, it is removed along with its edges and vertices. The other vertices that were connected to those edges are all joined to a new vertex at the midpoint of the collapsed polygon. Again, the effect is as if the original polygon was scaled to zero (below).

Collapsing selected polygon

When multiply selected polygons are collapsed, connected polygons are collapsed together as if they were a single polygon. Disconnected islands of selected polygons are collapsed separately.

To collapse polygon mesh components

Select some vertices, edges, or polygons on a polygon mesh object.
Press Ctrl+Delete or choose Modify Poly. Mesh Collapse Components from the Model toolbar.

Dissolving Components

You can dissolve components using Ctrl+;. When you dissolve components, they are deleted and the resulting holes are filled with new polygons.

NoteYou have the option of automatically cleaning vertices when dissolving. See Dissolving Components and Cleaning Vertices.

When vertices are dissolved, any edges and polygons that share those vertices are deleted and the resulting holes are filled (below).

Dissolving selected vertex
When edges are dissolved, any polygons that share those edges are deleted and the resulting holes are filled (below).

Dissolving selected edge
When polygons are dissolved, any edges and vertices that are no longer attached to a polygon are deleted and the resulting holes are filled (below).

Dissolving selected polygons
Note
- If you dissolve a single polygon, it has no visible effect.
- You cannot dissolve boundary edges.

To dissolve polygon mesh components

Select some vertices, edges, or polygons on a polygon mesh object.
Choose Modify Poly. Mesh Dissolve Components from the Model toolbar.

Dissolving Components and Cleaning Vertices

You can dissolve components and clean their adjacent vertices using the ; (semicolon) key. In addition to removing the selected components and filling the holes with new polygons, this also performs the following actions:

If a vertex was shared by three or more edges before dissolving, but shared by only two edges after dissolving, the vertex is then collapsed.
Vertices that were already shared by only two edges before dissolving are not collapsed.
Vertices that are still shared by three or more edges after dissolving are not collapsed either.

The following shows the effect of dissolving polygons and cleaning vertices:

Before

Selected polygons will be dissolved.

After: Dissolving and cleaning vertices Vertices shared by two edges after dissolving are collapsed (A).

Vertices already shared by two edges are not collapsed (B).

Vertices shared by three or more edges are not collapsed (C).

After: Dissolving only

To dissolve polygon mesh components and clean vertices

Select some vertices, edges, or polygons on a polygon mesh object.
Press ; (semicolon) or choose Modify Poly. Mesh Dissolve and Clean Adjacent Vertices from the Model toolbar.

For edges and vertices, you can also press Delete.

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