Default Shortcut: Shift + P
Menu Path: Create > Surface Tool
The Surface Tool is a sophisticated, context-sensitive tool for interactively creating strips of polygons. It is commonly used in conjunction with Surface Snapping to re-topologize an existing mesh. It can be used on a selected object to extend an existing mesh, or with nothing selected to create a new object.
The Surface Tool defaults to Multi Select mode. Clicking on a component will switch the selection mode to that type until you right-click or finish adding a strip of polygons. The tool behavior changes according to the current selection mode, as detailed in the "Context Sensitivity" section below. If a component is selected, right-clicking will deselect the component and return the tool to Multi Select.
Objects which are selected when you enter the tool will be available to add geometry to. Objects which are deselected will be used as snapping targets if Surface Snapping is enabled. If you are using the tool to create new geometry over an existing object, de-select the existing object before entering the tool.
The positions of components of the active shape, including those added by the tool, can be tweaked by simply clicking and dragging on them. (Note that this is different than using the Tweak command, which will not work while this tool is active. The behavior is the same.) If you tweak a component which is available to add geometry to (i.e. it is on the border of an open surface), the component will remain selected so you can start adding geometry. Right-click to deselect if you wish to continue tweaking.
- The behavior is similar to that of the Polygon Tool, which lets you draw or select each vertex of a new face in order. Click and drag to move vertices as you place them. Right-click to complete the face. If you enter the tool with nothing selected, it will default to Vertex mode so you can draw out the first face of your new object. This selection mode is also the only way for the Surface Tool to create polygons with more or less than 4 sides.
- A new edge will be extruded from the currently selected edge. Move the mouse without clicking to position the new edge. Click to create the edge, and drag to change the edge's size if desired. Right-click to cancel if you don't want to create a new edge.
- A new edge will be extruded from the nearest edge of the currently selected face. Move the mouse without clicking to position the edge. Click and drag to draw out a strip of polygons. Each polygon will be the same length as the first-created polygon. (Let go and repeat the click and drag process if you want sections of a different length.) Right-click to cancel if you don't want to create a new edge.
- If you are in Face or Edge mode, you can use highlighted edges to change the behavior of the tool. If the highlighted edge is adjacent to the selected edge, then clicking will merge the new face with that edge as well. Click and drag to position the remaining free vertex. This is useful if you want to fill in rows of polygons, for example.
- If the highlighted edge is not adjacent to the selected edge, it will be used as the termination point of the current strip of polygons.
- In both cases, Vertices will be highlighted in red where the new geometry will be merged with existing geometry.
The most common use of the surface tool is to create a new (usually lower-poly) object whose geometry follows that of some other object. To do this, deselect your target object and enter the tool. Make sure Surface Snapping is enabled and the target object is Ghost shaded. (This can be set up automatically in the tool's options.)
The tool will start in vertex mode, allowing you to draw the first polygon of your new object over the existing object. From this point, you can draw out new geometry by selecting vertices, edges, or faces and extending them. Be sure to highlight edges where you want the new geometry to be merged. Surface snapping is projected based on the current view, so it is helpful to remember to rotate the camera as you work to give a good projection. Use Vertex mode to draw faces which are not four-sided, or to fill in holes.
Enable Surface Snapping on Tool Startup
- This option will automatically enable Surface Snapping when the tool starts up, and revert snapping to its previous state after you exit the tool. This is useful if you use the tool primarily for drawing new geometry over an existing shape.
Ghost Shade Unselected Objects on Tool Startup
- This option will automatically set unselected objects to Ghost shading mode, and revert their shading modes to the previous settings on exit. This is useful if you use the tool primarily for drawing new geometry over an existing shape, as it is easier to see the new geometry.
- The Surface Tool works as a sticky key, meaning you can hold down the hotkey to temporarily enter the tool. Some users replace Tweak with this command because of its added functionality.