Quad patch create a flat grid with a default of 36 visible rectangular facets. A hidden line divides each facet into two triangular faces for a total of 72 faces. The plane can be convert into acurve shape from the quad patch.
Step 1: First of all, create a quad patch.
Figure 48: Quad Patch
Step 2: Select quad patch and click on the right button of mouse. Then click on convert editable patch.
Figure 49 Convert editable patch
Step 3: Set up the orthographic view. Then Select vertex mode and select some vertex as it has been given in the image.
Figure 50: Select vertex
Step 4: Click on move tool and move Z-axis up side.
Figure 51 : Drag Vertex