Tutorial 8 - Introduction to Polygonal Surface Editor
This tutorial assumes you have a basic understanding of "4D Blue" functions. It is an introduction to polygonal surface editor and explains the way it works and how it should be used. In a broad overview it covers the editor functions and options.
Step 1 - Switching into "Editor" mode.
	Create any polygonal object and select it. A "Polygonal Sphere" is a good example. Then select the "Surface Editor Toolbar".
	You will notice a "short" information dialog and a button asking you to create "Editable Object" constructor. Most objects in 4D Blue are parametric by default until they are changed to "Editable Objects". The advantage of it is that they can be easily changed and animated since the underlying polygonal or NURBS surfaces are always recreated as the parameters are changed. However, in order to perform more advanced operations on the surfaces, they have to be "frozen" and can't be anymore recreated as the changes would be immediately lost. "Editable Objects" or "Collapsed" constructor is what we need. It doesn't have any options, and internally it just stores the surfaces which then can be edited without any worry that they can be overwritten. The "Create 'Editable Objects' Constructor" button is just a shortcut to "Collapse All" operation on the transformation stack. If you don't want to collapse the whole stack, manually collapse the top most constructor. For this tutorial, just click on the button.
Step 2 - Editor top toolbars.
	You will immediately notice that the top toolbars has changed, and the selected surface looks different with a blue color and many more details drawn. The first new top button is a "Pivot Lock". Usually the pivot point is automatically recomputed when you select vertices, edges or faces and it is placed in the center of the selection. However, in many situations it is needed to "lock" the pivot to particular location and keep it there as you work with the mesh. After the pivot is locked, the "Move Pivot" tool can be used to position the pivot point at a desired location.
	The next two icons switch between the "World" and a "Local" mode. In the "World" mode the node XForm is used and the object is shown at exactly the same position as in regular mode. In the "Local" mode the object is positioned in its local coordinates.
	The next 4 top icons switch between the 4 different elements that can be worked on: Vertices, Edges, Triangles and Faces. Many operations work different way based on the "element" type mode and many work only in particular mode. Triangles are almost never used, but they still can be adjusted if needed. The bottom 4 icons switch between 4 different selection modes: Set, Add, Remove, Toggle. The set mode usually allows a single selection and works exactly like the regular select operation. The add mode allows to select more than one element by "adding" them to selected list. The remove mode removes selected elements from selected list. And the toggle mode switches the selection of the elements between selected and unselected. Try it now on your surface with different element and selection modes to get acquainted with them. Also don't forget that the "Ctrl+LMB" rectangle selection tool can be used as well. Try it as well.
	The first 4 icons in the bottom toolbar are additional new "operations" that can be used in the surfaces editor mode. They are "Move Normal" that moves the elements in the direction of the normal vector. Then is the "Scale Normal" that scales the element using the normal vector as the axis. The next two operators are the "Magnet" move operators. They work exactly as regular move operators, but they also adjust surrounding vertices based on their distance from the selected vertices--very handy when modeling a human face for example. The operator’s parameters can be adjusted in the "Tools Setting" rollup dialog in the side toolbar. As always LMB and MMB work different way for most of the operators.
	The next set of operators works on the selected elements almost exactly like their related transformations. For example, if you select the top faces of a sphere and use the twist operator, the operator will twist these selected faces. If needed, adjust the "boundary" settings if available and/or adjust the pivot point position to achieve expected results. Quite often it is needed. If things go wrong, always remember you can use the "Undo" option to go back to previous states.
	The next 3 operators add new faces to the mesh. These operators work only in the "Faces" mode. Pressing "Shift" when working with "Extrude" and "Bevel" enables them to share common edges between selected faces.
	The next groups of tools are simplified versions of the rollup dialogs from the side toolbar. They allow you to quickly perform the most common operations without the need to always scroll between the rollup dialogs. The first group is simplified version of "Select" Dialog. The number fields show the number of selected elements of particular type and the total number of elements of particular type.
	The next groups of tools are vertices tools. First button deletes all selected vertices. The second deletes all vertices that are no longer used (isolated). Third, changes the color of selected vertices. The fourth and fifth are used to weld and separate welded vertices. Welded vertices are like normal vertices except that in many operations they appear as a single vertex - especially important during subdivision.
	The next groups of tools are edges tools. The first button deletes selected edges and faces that use these edges. The second button performs "Loop Cut" - i.e. splits the surfaces into two around the selected edge loop.
	The next groups of tools are faces tools. The first tool deletes selected faces. The second extracts selected faces into new surface. The third flattens selected faces. The fourth flips the normals of selected faces. And the fifth split the selected faces into triangle faces if they are quads.
	The next groups of tools are mirror tools. The first button enables mirroring preview. The next three buttons control the symmetry axis. The object is always mirror with respect to the origin point - (0,0,0) and the selected axis. The last button performs the mirror operation - i.e. converts the preview surface into working surface.
	The next groups of tools are subdivision tools. The first two buttons control the number of subdivision iterations. The next button controls if the contour should be frozen or not. The fourth button controls whether faces or triangle edges that should be used. Most of the time the default faces edges are fine. The fifth button controls if the source surface should be displayed as well as the subdivision preview surface. Unless transparency is enabled, usually displaying only the new subdivision surface is the preferred way. The sixth button controls if the whole surface should be subdivided or only the selected faces. The last button performs the subdivision - i.e. converts the preview surface into working surface.
Step 3 - Editor side toolbar.
	The "Surfaces Editor Toolbar" contains the complete set of all editor tools and is most often used for more advanced or detailed operations. To simplify the editor workflow many of the commands has been replicated in the top toolbars as described above. Many can be also accessed from the custom context menu - RMB. Try it now too - the context menu in surface editor is slightly different from the usual context menu. To aid modeling two check boxes are shown below surface list. Enable them to reduce clutter on screen from other objects or surfaces.
	The editor dialogs are separated into smaller rollup dialogs to reduce the UI clutter and speed up accessing the necessary commands. The rollups that contain exactly the same commands that can be accessed from top toolbar are not described in detail below. The "Tools Settings" toolbar contains a dynamic dialog that changes based on the selected tool/operator. Often it is necessary to adjust values in it for the operators to work as expected. Unless needed, try to keep it always open.
	The "Vertices Parameters" dialog. Subdivision locked check box locks selected vertices during subdivision. They will not move. This is often handy if you need to keep few sharp edges. UVW coordinates are a very low level of adjusting UVW coordinates for every vertex. Usually last resort if nothing else worked. UVEdit tool when fully completed will be much better way to perform UVW mapping of a whole surface. Welding radius controls how close the vertices have to be to each other to be welded together. If the "combine" flag is selected the vertices are not welded but are combined instead. Often normal vector and UVW mapping information is lost in the process. Combined vertices can not be separated.
	The "Faces Parameters" dialog. Each face can belong to a single group. There is 64 maximum groups. Usually all faces are part of the same group, but at times it is handy to separate them into groups. Then a whole group can be selected, and the group material changed for example. Thus it is possible for single surface to use more than one material or have smooth and flat shading. The buttons works exactly like described above in the top toolbar section.
	The "Groups Parameters" dialog. As mentioned above, faces can belong to different groups. In this dialog each group parameters can be adjusted.
	The "Mirror Surfaces" dialog. It contains almost exactly the same commands as the top toolbar, but it also allows you to precisely specify the "Axis Threshold" value. This value is used to specify how close the vertices have to be on the axis plane to be considered as "center" vertices.
	The "Subdivision Surfaces" dialog. The iteration count controls the number of subdivision iterations that are performed to create the final subdivided surface. The more iterations, the smoother the surface will be, and also the larger it will be. Subdivision weight controls the smoothness factor. A subdivision with weight 0 will simply tessellate the surface, which at times is exactly what is needed. A weight of 0.5 produces the smoothest surface. Smaller weights maintain some level of "edginess". Weights that are higher than 0.5 produce interesting, but often strange results.
	The "Display Options" dialog. This dialogs controls what elements of the surface are displayed when they are unselected and selected. It is often good idea to avoid mismatching between selected and unselected elements - i.e. if selected vertices are display, most likely unselected vertices should be displayed as well. Of course, there are exceptions to it. Display only the elements that you need to reduce the amount of clutter on the screen. Try all the options now to get familiarize with them. Switching between different display modes when modeling an object is often necessary. The custom context menu (RMB) is often handy as a quick alternative to set display parameters as it contains all the display flags.