Bumps is the indentations and unevenness provided on the surface. Using the bumps property, a smooth surface can be given an irregular and rough appearance.
The following are the Bumps options available in the drop down list:
| None | The surface is smooth without bumps. |
| Casting | The surface will have an irregular casting pattern. |
| Rough | The surface will have a rough, cast metal-like finish. |
| Wrapped bump map | The surface can be mapped by a bump image. |
| Wrapped dimple | The surface will have a regular dimpled appearance. |
| Wrapped knurl | A knurled pattern will be visible on the wrapped image on the surface. The knurling pattern is similar to the grips seen on tool handles. |
| Wrapped rough | The surface is wrapped with a rough, cast metal-like finish. |
| Wrapped tread plane | The surface is wrapped with a regular tread plate pattern. |
| Bum wrapped leather | Similar to the details of the surface of the leather. |
| Leather | The surface will appear similar to leather. |