Rasterizing a Shape Layer
Photoshop CS3 Tutorial
How to Rasterize a Photoshop Shape Layer
Shape Layers are vector based layers where the shapes are defined by multiple control points. By moving the control points, the shape can be edited.
You can't paint a shape layer until it it rasterized. Once the layer is rasterized, it becomes a bitmapped image and is defined by a series of tiny square pixels.
Open a blank document in Photoshop (File > New). Set the size to 500 pixels by 500 pixels at 72 ppi.
Select the Ellipse tool and set the options to Shape Layers.
Draw an ellipse in the workspace.
Click on the shape layer in the Layers palette.
To rasterize the shape layer, choose Layer > Rasterize > Shape. Notice that the layer thumbnail converts to a normal layer. Once rasterized, the shape control points are no longer editable.