The
Mesh Warp effect applies a grid of Bezier patches over a layer,
which you can manipulate to distort areas of an image. Each corner
of a patch includes a vertex and two to four tangents (points that
control the curvature of the line segment that makes up the edge
of the patch). The number of tangents depends on whether the vertex
is in a corner, on an edge, or inside the grid. By moving the vertices
and tangents, you can manipulate the shape of the curved line segment. The
finer the grid, the tighter the adjustments you can make to the
area of the image inside the patch.
This effect works with 8-bpc and 16-bpc color.

Original (top left), with distortion mesh (bottom left), and
with Mesh Warp applied (bottom right)

To
select multiple vertices, Shift-click the vertices.
- Rows, Columns
-
Specify up to 31 patches vertically (Rows) or horizontally (Columns).
For broader distortion, use fewer patches. For finer control, use
more. Drag the vertices and tangents to change the grid shape. The
image follows the grid shape according to the elasticity setting
and the boundary created by the adjacent patch.
- Quality
-
Specifies how closely the image follows the shape defined
by the curve. The higher the quality value, the more closely the
image follows the shape. Higher quality settings require more rendering
time.
- Distortion Mesh
-
Click the stopwatch to animate the distortion over time.
Note: Each
patch becomes a boundary for the distortion. For example, when you stretch
a patch, the area of the image in the patch stretches, squishing
the area of the image in the adjacent patch. The boundary of the
adjacent patch protects the image inside it from being squished
to zero. In other words, you can’t push an image out of its patch.