Maya provides an entire battery of tools and basic surface types that will enable you to model virtually anything. The text describes the basics of polygon modelling, the most commonly used tools and some tricks; Subdivision surfaces are also mentioned. It includes an introduction to topology and some general modelling advice.
The text is primarily intended for beginners. However, advanced modellers and digital sculptors may learn some tricks from it as well.
The text is not meant to be an instruction manual, therefore it does not list all possible tools. It describes the author’s favourite tools, including practical examples. It is recommended that you try out a variety of tools and experiment with them, seeking further (better) methods. To learn to use Maya even better, look up detailed information in the manual.
Note: The tutorials assume a basic understanding of navigation, node-based philosophy, UI and manipulation of objects in a scene.
- Description of polygons and how to create them
- Polygon components
- Selecting components
- Displaying polygons, normals, snapping, pivots, poly count, Custom polygon display
Description of polygons and how to create them
Modelling by means of polygons and Subdivision surfaces has become very popular recently. NURBS surfaces are still being used, but even big effect studios, whose procedures and pipeline were centred on NURBS, are gradually switching to polygons and Subdivision surfaces. NURBS surfaces are still indispensable in design.
Description of polygons
A polygon is a geometrical shape of n edges. Objects and models consisting of polygons mostly contain squares and triangles, but many-sided polygons may be used as well.
A polygon is defined by its vertices (control points) which are connected by edges. The “filling” within them is called Face (the word “polygon” may also be used).
A polygon is either planar, i.e. all its vertices lie in one plane, or non-planar – not all the points lie in one plane. A triangle is always planar. Renderers automatically break all shapes up into triangles before rendering.
Creating polygons and polygon primitives
There are several ways to enter polygons into Maya.
1. by inserting predefined primitives
Primitives may be found in the menu [path]. Some are very useful and save modelling time.
You can set various parameters (such as size, detail etc.) in the Option Box before inserting a primitive. However, I prefer to keep the default values and reset them after insertion in the Channel Box.
2. by creating a polygon using the Create Polygon Tool ([path])
You can place vertices by clicking into space.
You can complete a polygon by pressing Enter. However, doing that deactivates the tool.
To confirm a polygon and continue using the tool, press y.
Delete or Backspace deletes the last point placed.
Insert activates the Manipulator mode which allows you to change the position of vertices; to return to normal mode press Insert again.
To create a hole in a polygon, hold Ctrl while placing its first point (not necessary for the others).
Ensure Planarity in the tool settings or Keep New Faces Planar in [path] ensures that thus created polygons are planar.
Append To Polygon Tool ([path]) works like Create Polygon Tool, except that it adds a polygon to already existing geometry.
To add a polygon, click on the edge of an existing one to which the new one should be appended; then create the polygon in the same way as with Create Polygon Tool.
3. by conversion from another type of surface, e.g. NURBS.
4. by importing a model from other software.
Polygon components
When a polygon (or other) object is in a scene, it can be manipulated as a whole – moved, rotated, enlarged etc. Such a situation is called Object mode.
To change an object’s shape, add geometry etc., switch to Component mode which allows you to adjust vertices etc.
The basic components that constitute a polygon and can be manipulated are
Vertex (control point)
Edge (connects vertices)
Face (the polygon itself)
There are several ways to switch from one component to another or to Object mode:
1. Marking Menu
If you click the right mouse button above an object and hold it down, Marking Menu will appear. To select a component, drag the cursor to the appropriate button and let go. Marking Menu also allows you to switch to Object mode.
Using Marking Menu has one disadvantage. Let’s say you enter Component mode via MM and want to select several vertices e.g. by means of marquee (drawing an oblong) or lasso. If there is another object nearby and you select it while selecting the vertices area, it will be included in the selection. This may be useful in some cases, as you will find out later. Otherwise it is quite counterproductive. That is why I mostly use keyboard shortcuts to switch between components.
2. Shortcut keys
- F8: Object Mode
- F9: Vertices
- F10: Edges
- F11: Faces
If you enter Component mode by shortcut key, you will not select an undesired object, which may happen when using marquee selection or lasso.
The last possible way of switching is by means of the Status Line, where there are buttons for switching to Component and Object Modes a where you can find the various components in the menus. I find this way very slow, also because I keep the Status line hidden while modelling.
Object Mode
Component Mode
You can manipulate components by means of familiar tools – move, rotate, enlarge, snap, delete them and much more.
Selecting components
The basics of selecting components, basic tools
- left click: selects a component
- Shift+ left click: adds to current selection
- Ctrl+ left click: unselects a component
- left click + drag : defines the area to be selected by an oblong (marquee selection)
- Lasso tool (available in Toolbox): selection by lasso
Edge loop
Edge loop is a series of connected edges that “run” along a surface. Sometimes the beginning and end meet, forming a loop.
When an edge loop meets e.g. a 3- or 5-path “crossroads”, like in the following picture or the Ear picture, it finishes there.
There are several ways to select an edge loop in Maya.
1. Click on an edge of an object and choose [path] > Convert Selection To Edge Loop
2. By the Select Edge Loop Tool ([path]) which only serves to select edge loops.
Doubleclick on an edge to select an edge loop.
To select a part of an edge loop, left click on the first edge and again on the last one. Hold down Ctrl while clicking to deselect a part of a selected edge loop.
The tool allows you to select a number of tools without having to leave it.
Edge Ring
Edge ring is a strip of edges connected by their shared polygons.
Selecting and Edge Ring is similar to selecting an edge loop.
1. Select an edge and choose [path] > Convert Selection to Edge Ring.
2. By the Select Edge Ring Tool ([path]). Works like Select Edge Loop Tool except that it selects a “strip of edges”.
Border Edge
Unless a polygon object is closed like e.g. a sphere, it contains edges that define its borders. In Maya terminology these are called “Border Edges”. We can select these edges in the same way as others. However, it is often necessary to select a whole border or a part of it. If you try to use one of the ways of selecting edge loops, it will not work for border edges, even if the border edges form a loop. In Maya there is a special tool for selecting border edges: Select Border Edge Tool. You can find it under [path] > Select Border Edge Tool.
It works just like the tools for selecting edge loops and edge rings described above. Therefore doubleclick to select a whole border. Left click on the first and then last edge to select the part of the border thus defined.
Paint Selection Tool ([path])
The Paint Selection Tool allows you to select components by “painting” on the surface of an object.
The tool has quite detailed options settings, I will only mention the most important items.
section Brush:
- Radius U: allows you to adjust the brush radius
- Profile: determines how gradual the selection should be or changes the brush shape
section Paint operations:
- Select: the brush selects components
- Unselect: the brush unselects components
- Toggle: the brush inverts the selection, i.e. unselects selected components and selects the others
- Select All, Unselect All a Toggle All: works like the brush except that it affects the whole object – i.e. all its components.
- Add To Current Selection: when this option is on, new components are added to the selection with every drag of the brush
section Display:
allows you to set what should be shown in the viewport while painting the selection
Unless you want to spend time setting options whenever you select something by the brush, it is useful to set it for universal use and then open the tool itself without the Tool settings.
If you want to change the brush radius quickly while painting a selection, hold b key; a both-sided horizontal arrow will appear in the middle of the brush. If (while holding b) you left click in the viewport and drag rightwards, the brush will enlarge, dragging leftwards will diminish the brush.
Invert selection ([path])
Invert Selection inverts the selection. It is useful e.g. when you need to select everything except a few components. One way to do this is to select all by marquee selection (drawing an oblong) and unselect those few components. Or you can use Invert selection – simply select the components and choose Invert Selection. The selection will be inverted.
Convert selection
Convert selection is useful when you have selected one type of components and need to convert it to another type. E.g. you have selected an edge loop and want to convert it to a selection of vertices.
You can convert various selected component by means of:
- [path] > Convert Selection to Vertices (Crtrl+F9)
- [path] > Convert Selection to Edges (Ctrl+F10)
- [path] > Convert Selection to Faces (Ctrl+F11)
You will have noticed that I have not mentioned all, just those most often used. The shortcut keys are given in brackets as quicker alternative. Moreover, the F-keys refer to the various components. Therefore if you switch to vertices by F9, Ctrl+F9 converts the selection to vertices.
A fairly interesting function is [path] > Convert Selection to Face Path.
It converts the selection to a “strip of polygons”. If you e.g. select an edge and choose Convert Selection to Face Path, the result will be similar to choosing an Edge Ring and converting the selection to faces (polygons).
Instead of a strip of edges you will get a strip of polygons.
Let me give an example of practical use.
Let’s say that for the following front panel of a car we want to select all the polygons in the part extruded inwards (see figure).
Normally, we would have to select the polygons one by one with Shift (or by the Paint Selection Tool).
However, if we only select the edges determining the “depth” of this part …
… and choose [path] > Convert Selection to Face Path, the whole part will automatically be selected and the selection converted to a “strip of polygons”.
Note: The same result may be achieved by selecting edges, converting the selection to an edge ring and further conversion to faces (Ctrl+F11).
Grow and Shrink Selection Region
- [path] > Grow Selection Region widens the current selection.
- [path] > Shrink Selection Region narrows the current selection.
I have not found much use for these yet, but you never know – they may come in handy.
Selection Constraints ([path])
Selection Constrains is a rarely used tool, but it might be useful to be aware of it.
It works as a filter which determines what should be included in a selection.
Before using S. C. the selected object can be in Object Mode, i.e. a component need not be selected. You can switch between components while the S.C. option box is open. This will also affect various option menus, e.g. there are more options for faces than for vertices.
In the upper part of the dialogue box under “Constrain:” we can determine when the limitations should apply.
Nothing: does not change the current selection
Current and Next: the limitation applies to current and next selection
Next selection: the limitation applies to next selection
All and Next: the limitation applies to current selection, selects all components, then works for the next selection as well.
I mostly use Current and Next, possibly All and Next.
The tool contains a number of sections where you can define what the selection should be limited to.
Let us give examples of some of the options:
Properties > Location > OnBorder: selects only the components on the border.
On the other hand Inside limits the selection to components that are not on the border.
Properties > Order > Triangles: selects only triangular polygons, this option is obviously available only for components of the Face type (polygons).
“Quads” limits the selection to quadrangles and “Nsided” to 5- and more-angled polygons.
Reset > Disable All in the menu option box turns all limitations off.
Close and Reset: closes the option box a resets all limitations to default setting, i.e. none. However, the current selection remains unaffected. There will be no limitations for the next selection.
Close and Remember: closes the option box, but remembers the limitations for all further selections, until you activate Selection Constraints again and reset the options.
Isolating a part of a model
Sometimes you need to concentrate attention on a certain part of a model, and apply some modelling processes to it only. For this purpose serves the option Show > Isolate Select > View Selected in the viewport menu. It is available for every viewport.
Select the faces you want to isolate, apply this option and only the selected part will remain in the viewport. You can then do modelling operations on it. To display the rest of the model as well again, apply the function again (untick View Selected).
Tip: To do the opposite, i.e. hide the selected polygons, do the inversion of selection ([path]) mentioned above before applying Show > Isolate Select > View Selected.
Saving the component selection
The possibility to save a selection of components is another useful modelling tool.
You might know already that it is possible to save a selection of objects under a name and later activate them again by means of Quick Select Sets.
This procedure may be used for components as well, it allows you to save selected polygons, vertices, edge loops etc.
To save a set, select the components and apply [path] > Quick Select Sets… . Name set.
To activate a set again, go to [path] > Quick Select Sets a select its name.
You can save a number of sets in this way.
Pick Walk
The so-called Pick walk is quite useful in some cases, e.g. when there is a lot of geometry and it is difficult to select a vertex without selecting something else. Or when there is a manipulator in the way.
It allows you to select vertices by the cursor arrows on the keyboard. In fact you can “navigate” the selection along an object.
Just select one vertex and then move by the cursor keys in 4 directions. The selection jumps to the neighbouring vertex.
There is one limitation – you cannot select vertices that you cannot see in this way. However, all you need to do is change the camera angle.
Displaying polygons, normals, snapping, pivots, poly count, Custom polygon display
Custom polygon display
[path] > Custom polygon display > option box allows you to set displaying of polygons and their various qualities in the viewport.
Again, I will only mention the important ones, in order not to bore the leader.
Objects Affected >
Selected: the display change applies only to selected objects
All: the display change applies to all objects in the scene
The section Vertices allows vertices to be displayed even when you are not in the Component mode of vertices; it also allows the normals of vertices to be displayed.
Edges – displays hard/soft edges
Highlight>
Border Edges: a very useful setting, allows you to set highlighting of border edges
Edge Width: allows you to set the width of highlighted border edges
Face>
Centers: displays little squares that represent the centres of faces. If your faces are set without these squares like mine, displaying them temporarily allows you to discover polygons with zero edge length.
Normals: displays normals of faces, useful when you need to check the direction of normals
Non-planar: highlights non-planar polygons
Show Item Numbers – displays the numbers of components
Normals Size – allows you to set the length of displayed normals
Backface Culling
The default setting of Backface Culling is Off, you can see all the polygons of an object, including those that are “on the dark side” of the model (not in the camera range). You can also select components of “dark side” polygons (e.g. by means of marquee selection).
If you turn BC on, the dark side polygons will neither be displayed nor will you be able to select their components, until you focus the camera on them.
The mode Keep Wire displays dark side polygons, but does not allow you to select their components. It is therefore a certain combination of the two above.
Normals
Every polygon (face) has its normal, which is the vector perpendicular to its surface. The normal is always on one side of a polygon only. The front of a polygon is the side from which the normal points into space. There is no normal on the backside.
Displaying normals allows you to see their direction and determine the front of the polygon.
Once you get to smoothening objects, you will appreciate the importance of checking normals.
You can display normals by [path] or [path]> Custom Polygon Display > option box > Face: tick the item Normals
The [path] > Reverse allows you to reverse normals to the other side. You can select a whole object and reverse its normals. The same can be done with individual selected polygons.
If the tool is set to the mode Reverse, the normals of selected polygons or a whole selected object will be reversed, the others will not be affected.
If you want to reverse the normals of selected polygons and all the other normals of a model as well, choose the option Reverse and Propagate. I have not used this option so far.
I personally have the tool set to Reverse and keep this option by means of Save Settings.
If you run into problems while modelling, wrong direction of normals might be the cause. If all the normals of an object do not point in the same direction, problems are bound to occur.
To correct such a situation use the [path] > Conform.
When this is applied, all the normals will point in one direction, whether inside or outside an object.
If the normals of some polygons pointed different way than the others, this will unify the direction.
In general, the normals of a model should point outside, not inside it (there are exceptions to this rule). If they point inside after applying Conform, turn them outside by Reverse.
We will discuss normals further when we get to smoothening of polygons.
A troublesome object seems alright at first glance.
Displaying normals will show the problem part – where the normals point in the opposite direction.
Applying Conform to a whole selected object will make its normals point in the same direction.
Vertex Normals and Soften/Harden Edge
Vertices also have normals (not to be confused with normals of faces). They determine how soft the transition of shading between faces will be. Each vertex has a number of normals equal to the number of faces sharing this vertex.
By changing the angle of normals you can achieve soft transitions of light on the edges, and therefore softer edges, or else hard transitions, where individual facets can be distinguished.
To set the angle of vertex normals in Maya, and thus the softness of shading transitions as well, there is the tool [path] > Soften/Harden > option box.
The bigger the angle you set, the softer the shading will there be on the edges.
The button All Hard serves to set extremely hard edges quickly (0 degrees; vertex normals pointing in the direction of faces).
The button All Soft shifts the slider to 180 degrees and ensures the softest possible edges (vertex normals pointing in the same direction).
The following example shows a sphere of glossy material. At first, All Hard was set and then rendered. In the second case, All Soft was set and again rendered.
All Hard:
All Soft:
Vertex normals can be displayed by [path] > Custom Polygon Display > option box. In the section Vertices tick Normals. This allows you to see what normals look like at smooth and hard shading.
All Hard, vertex normals point in the direction of faces:
All Soft, vertex normals point in the same direction:
You can also change the hardness of the shading of individual edges or faces, by selecting them and setting the angle or choosing All Hard/All Soft. In the following example All Hard was applied to selected edges.
Such adjustment of edges hardness can be useful e.g. when you have model which you do not want to smoothen further by means of a smoothening algorithm, but you need to sharpen the edges in some places.
Snapping
Very often it is necessary to snap some components to others or e.g. to a curve.
This simply means moving them to that place, not that they become constrained there in any way.
The following examples show snapping components that also works for whole objects, if you want.
The tool Move (key w), used for snapping, includes a setting called Keep Spacing.
When this is off, snapping the selected vertices moves them all to the destination point. When it is on, vertices keep their original spacing after being moved and snapped.
To turn Keep Spacing on/off, hold w key and click anywhere in the viewport with the left button, holding it down. This activates the Move Tool Settings (by means of the Marking menu), where you can turn Keep Spacing on/off. I keep it on all the time (tick (x) next to the name).
w + (left click + hold):
You can also turn Keep Spacing on/off in the Move Tool Settings – to activate it click the icon Move in the Tool Box or display it instead of the Channel Box.
Here the option is not called Keep Spacing but Retain Component Spacing. However, it is the same.
We want to snap these vertices to the apex of the pyramid.
Keep Spacing On:
Keep Spacing Off:
You can snap to:
- 1. vertices/CVs – hold v key
- 2. edges/curves – hold c key
(if you hold down the middle button and drag in some direction, you can slide along an edge/curve) - 3. grid – hold x key
You can also activate snapping in the Status line, just make sure you don’t forget to turn it off again.
Rightwards: grid; edges/curves; vertices/CVs/points:
The snapping itself is done as follows:
- 1. Select the desired components.
- 2. Activate the Move tool, unless it is already active.
- 3. Choose the kind of snapping (point, edge/curve, grid) and hold the respective key (or select the kind of snapping in the Status line).
- 4. Click on the “destination” of snapping with the middle button. (Of course you can just move the selection with the left button to the destination, and snap it thus, but I recommend the way using the middle button which ensures that the selection does not snap to something else along the way.)
Example:
Select the vertex.
Hold v key.
Click with the middle button on the destination vertex.
If you want the component to snap, but move along a certain axis, select the desired axis of the Move manipulator (it becomes yellow) before snapping the components.
Select the axis.
Hold v key.
Click with the middle button on the destination vertex. The selected vertex will move to the level of the destination vertex along the Y axis, because the movement was limited by this selected axis:
You can also snap components to the components of the object you are working with. If you e.g. select a vertex, you can slide with it along the shared edge by means of snapping to edge.
Setting the pivot while transforming components
While transforming components you sometimes need to adjust the “action centre”, i.e. the pivot.
Logically, the pivot of a transformation is where its manipulator is. If this does not suit you, you can change it by moving the pivot of the transformation.
As in the case of objects, switch to Pivot mode by pressing the Insert key; then you can move or snap the pivot (e.g. to a vertex, edge etc.). You leave the Pivot mode by pressing Insert again.
Tip: To enter Pivot mode quickly use d key – you are in Pivot mode while you hold it, you leave it when you release the key.
Example: We want to diminish the following faces in the direction of the centre of the prism.
However, the tool always diminishes in the direction of the pivot which is not placed properly. The result would look as follows.
Therefore we will snap the pivot to the vertex on the centre of the prism and leave the Pivot mode.
Now we can diminish in the direction of the new pivot location.
Poly Count
To find out how many polygons there are in your scene, how many polygons constitute a selected object or how many components have been selected, you need Poly Count, accessible by [path] > Poly Count.
Poly Count basically consists of a table.
The rows state what components are being determined:
- vertices
- edges
- faces (polygons)
- triangles (after dividing before rendering)
- UV axes
The columns are as follows:
The upper figure therefore tells us that there are 1617 polygons (Faces) in the viewport, the selected/”active” object (a sphere in this case) has 780 edges and 181 vertices have been selected.
If you want to know the exact number of polygons (or other items) in the scene, you must zoom out the camera in the viewport to see the whole scene, because the first column gives the number of components in the viewport, not the whole scene.
Not all the objects are within the camera range (in the viewport). 415 polygons in view:
Zoomed out to the whole scene, e.g. by means of a key. 1617 polygons in the whole scene:
Determining the number of selected vertices can be useful e.g. to discover unwanted geometry which exists in the same place as the one you are working with. In such case you will find e.g. 2 vertices where there should be 1.
… to be continued, stay tuned!