3D OBJECTS

Maya allows you to model 3D objects as either polygons or NURBs.

A polygon is a familiar 3 dimensional shape made up of polygonal faces, e.g. a cube is made up of six square faces.

There are three different types of polygonal faces:

• Quads have four edges, e.g. a sphere is made up of a number of quads, and quads is the default shape to model with, as they are easy to subdivide, to texture upon, and its more predictable to deform.

• In-gons have more edges than four: e.g. a polygon with 6 edges is an icosohedron. You should avoid these where possible because you can have issues subdividing them.

• Tris, or triangles, are the lowest number of edges to define a face in 3d space. In games triangles are more common because the geometry needs to be simple. Note that when objects are rendered, they’re often broken into tris by default.

The more polygons an object has the more processing power is required to represent it but the more complex and smooth it looks. If you are creating a model to render as an external image the number of polygons might not be a factor, but in a game in which multiple objects are moving in response to dynamic player input the number of polygons can become an issue.

Consequently, it is common to ‘optimise’ game objects, either by making sure they have as few polygons as possible (a ‘low poly count’), or by creating multiple versions of the same object so that the game engine can swap models of a different Level of Detail (LOD) depending upon how far away it is. By analogy, in a movie the weapons, clothes and armour of the main characters in close-ups are much more detailed and carefully produced, whereas the props of background characters are less detailed and mass-produced.

NURB stands for a ‘Non-Uniform Rational B-Spline’, which sounds complex but is basically just a 3D object whose surfaces follow underlying curves whose paths are defined by control points. The example below shows a tube extrapolated from a swirling curve; a real life example of the same kind of process would be twisting a wire to pass through several points on a piece of paper (the ‘curve’) and then wrapping a tube around the path of that wire (the ‘surface’).

An analogy for polygons vs nurbs is raster vs vector. Many images are raster, meaning they are made up of individual pixels and if you zoom in on them, or rescale them larger, they look blocky, losing quality (you can see this effect if you zoom in on the raster image above until the pixels become clear). By contrast, vector graphics are not made up of pixels, but a mathematical description of a shape. Fonts operate this way, allowing you zoom in and rescale them for screen or print without losing fidelity (if you zoom in on this text, you will find it stays crisp). Just as you need more pixels, i.e. a higher resolution, for a picture to look good when zoomed in, a polygonal mesh needs more polygons to look good at high resolution. However both vector and NURBs can look good at any resolution.

Note: Polygons are the industry standard in games, and it is possible to work in Maya without using NURBs. However, some highly curved or complex objects are much easier to make as NURBs, so it can save time to make an object as a NURB and then convert it to polygons.

WORKFLOW

‘Workflow’ just means ‘how you do things’ and is a term is used in modelling, animation, software development and many other artistic and technical fields. The term ‘pipeline’ often is used as a synonym for workflow, but places greater emphasis on how certain things need to be done in sequence, usually as part of a larger project, e.g. a 3D model needs to be made so that ‘further down the pipeline’ a 3D artist can create textures for it, and needs to be ‘rigged’ so that ‘further down the pipeline’ an animator can pose and animate it.

Maya has some standard workflows, but there is rarely a single way to do something. When you load the program you will see so many features it is typical to be overwhelmed. It is best to begin by performing small tasks to figure out one basic workflow, e.g. how to create a polygon, how to select different parts of a polygon, how to modify parts of a polygon, and so on.

From there, you should experiment with the Maya interface, ignoring icons, terms and functions you don’t need, and slowly introducing features to your workflow. If you repeat tasks the interface and basic workflows will become familiar and you will find a workflow that works for you.

Perhaps the most useful thing to learn are Hotkeys, i.e. keyboard shortcuts which save you from navigating menus and icons. For example, Ctrl+S will save a scene you are working on, H will let you hide and reveal a selected object, and so on. You can see a full list of these in the Maya documentation.

GETTING STARTED

To get started you need to have Maya installed on your computer and start the program. Students and teachers can get a free license to download and use Maya using their institution’s e-mail from: https://www.autodesk.com/education/free-software/all

When Maya is installed on your computer:

▶ Double click on the Maya icon to load the program.

You will see an Output Window that gives you information about the version of Maya you are running and other information. You can ignore or close that window.

When you first load Maya an introductory window usually pops up with links to some short tutorials and indicates that any new features since the last version of Maya will be highlighted. You can untick the box so they do not show on startup and subsequently access that information via the Help Menu.

While the following document and its accompanying videos serve as a good introduction to Maya, you need to get used to finding a wide range of available resources online, much of which involves basic Google searches with a clear description of what you want to do.

• Autodesk online manual

• View Maya hotkeys

• Maya 1-minute startup movies

• Online forums

• Youtube tutorials

• Maya Tutorial for Beginners (1:48:15)

• Lynda.com: Maya 2018 Maya Essential Training

SELECTING AND EDITING POLYGON COMPONENTS

Once a polygon is created you can select it with the LMB. However each polygon is made up of different components, and you often need to select one or more of these rather than the entire object:

· Vertex: a point in 3d space, a dot represented by x,y,z (vector 3d)

· Edge: a line that connects two vertices

· Face: the visible surface, or plane, between 3 or more edges.

Click the RMB to bring up the selection menu to choose the type of component you will select:

The colour of an object’s components will change from red, green to orange if you roll over, select or roll off a selected object. The image below shows the three main types of selection: vertex, edge and face, respectively.

In addition to selecting a vertex, edge or face, you also have options for:

· Object: the entire object

· Multi: will select whatever type of component you click on.

We also can click the icon for Select by Component Type in the Status Line, and clicking the bar to its right to bring up icons for the type(s) of component selection you want to be active.

Changing selection modes plus using the hotkeys for the core Tools: Q (Selection), W (Move), E (Rotate) and R (Scale) is the best starting point for basic modelling. The image below shows a simple example of two vertices of a cube that have been selected and moved away from the rest of the cube.

The base shape will highly determine the kind of shapes you can build from it. This is similar to how, when learning to draw, it helps to break a complex shape, like a person, into simple shapes, such as spheres and cylinders, except in a 3D package you often literally create complex objects from a series of simpler objects.

ADDING FACES

When we create a polygon we have a default size and number of faces, which limits your ability to manipulate it, but there are three main ways you can quickly add additional faces, or ‘subdivisions’:

1. As noted above, use Create > Polygon Primitive but choose the □ option box, define the polygons size and other settings, then click in the view panel to create it. These settings will apply each time you click on the icon to create that type of primitive.

2. In the Channel Box we can set the defining properties, e.g. the radius, width, height, depth and so on, depending upon the polygon. The number of polygons can be altered by changing the Subdivisions Axis.

To access this, click on the INPUTS options for the object, e.g. polyCube1, and you will reveal some additional options. In the example below, a basic cylinder has had its height subdivisions increased from 1 to 6, which has added faces up its sides. You can change a variable either through 1. direct input, or 2. clicking on a variable, moving the cursor over the view panel, then holding the MMB and draggin left or right to increase/decrease the variable(s). You also can use <SHIFT> to click on and highlight (blue) multiple variables and edit them all at the same time.

3. In the Attributes Editor, we have a host of different tabs (or ‘nodes’) that identify a different range of an object’s properties. In this case if you look for the geometry tab labelled according to the type of polygon, e.g. polyCylinder1, you will see some of the same variables as in the Channel box, but you can adjust them via the sliders. In the example below, the same cylinder has had its axis subdivisions reduced from 20 to 9, making it more blocky.

EXTRUSION

While the Move and other basic tools give you the ability to make drastic changes to a polygon, often you will want a more precise ability to deform faces: the extrude tool is particularly useful for this.

▶ Right click and select Face

▶ Left click on one or more faces

▶ Edit Mesh > Extrude (or Ctrl E).

This will allow you to extrude the selected faces, i.e. pull them in or push them out, without deforming the surrounding geometry.

The extrude face pop-up menu will let you manipulate Thickness (degree of extrustion), Offset (scale), Divisions (how many subdivisions are added to the extruded volume) and Keep Faces Together (which will move all selected faces as a single group).

You can extrude edges as flat planes, and points as triangles. However, you can only extrude from existing geometry, which means sometimes you may have to create additional edge loops or subdivisions until you can isolate a face to extrude.

SYMMETRY

Many objects, such as animals, characters and vehicles, are symmetrical, so you often want changes made to one side of an object to be reflected on the other side.

▶ Double click on a Tool, or click on the Tool Setting icon or tab, to bring up Tool Settings

▶ Scroll to and open the Symmetry Settings submenu, and click on the arrow to open the Symmetry dropdown menu (if it is greyed out it may be because your Soft Select is still active).

▶ Set Symmetry to off, or x, y and z for either Object or World space, or to Topology.

By default you would use Object space, but there are instances you might want to mirror World space or use a reference point for your symmetry. Depending upon the orientation of your object, you may have to change these axes and select parts of the object to check that the symmetry is working the intended way.

The Tolerance setting determines the minimum amount of movement before which Maya will start mirroring your changes. This would be useful if, say, you wanted some minimal differences in symmetry to better capture the imperfection of a natural or damaged object.

The seam options are for NURBs, so you can ignore this for now.

Note that as you start selecting and moving groups of vertices, edges and faces you want to avoid them overlapping so that some become hidden inside the object. This may not be an obvious issue while building your basic shape, but geometry with overlapping or hidden vertices has major implications later in a modelling pipeline. If you smooth overlapping geometry you can end up with warping or pinching effects, and animating such geometry can lead to unexpected deformations; furthermore, if you add UV textures, or colour, to problematic geometry the textures may be correspondingly warped or pinched.

SOFT SELECT

If you select several vertices and move them, or extrude them, you will find that they create sharp contrast with adjacent vertices. If we want a more organic manipulation, you can use soft select.

▶ Double click on a Tool, or click on the Tool Setting icon or tab, to bring up the Tool Settings panel

▶ Scroll to and open the Soft Selection submenu and toggle the Soft Select option (you can press B as a shortcut to toggle this).

You will see the display will change with a colour gradient on the edges and vertices, showing the degree to which manipulation will affect the highlighted region more organically. This will work for the Move, Rotate and Rescale tools.

The Falloff radius is the most important feature, as it determines the scale of the soft select function. However, you can control the way in which the falloff works by adjusting the Falloff curve, as well as the interpolation mode, and you have some presets for these curves.

You also can change the Falloff colour by just left clicking on the colours or moving their position; however this is just to change the visual interface that shows the falloff settings.

Note: make sure you turn off Soft Select when you’re finished.

SMOOTHING

Physical objects have a combination of smooth and sharp edges. There are four main methods of creating smoothness:

1. Smooth Mesh Preview Smoothing

Use the number keys 1-3 to preview your object:

1 – shows your base geometry.

2 – shows your smooth mesh with your geometry overlaid.

3 – shows a smooth mesh preview.

Select Mesh > Smooth and it will apply smoothness. You can edit the number of divisions it uses to smooth your object, or initially choose the option box to edit the subdivisions as well as other controls. This will retopologise the object in the manner of your smooth mesh preview.

2. Crease Tool Smoothing

Use the Mesh Tool > Crease Tool to select edges and move them along to create sharpened edges

You could use the Mesh Tool > Crease Set Tool to add a series of creases to a single set to get consistency across a series of edges.

3. Edge Loop Smoothing

We could also Edit Mesh > Insert Edge Loop Tool to add a new loop of polygons .

4. Subdivision Smoothing

1. View Modify > Convert To > Subdiv

2. In Component > Vertex mode you will see the base complex geometry, but if you select a vertex and right click > Refine Selected you will create more detail. Each Refine Selected will alter the Display Level in the Attribute Editor.

If you go into Display > UI Elements > Polycount you can track the number of verts, edges, faces tris and uvs.

ACTIVITY: SIMPLE BOX MODELLING

The process of creating basic primitives and modifying them is called ‘box modelling’ and it allows you to create very complex objects.

You should experiment by creating a dome, a chair, and some other simple shapes, and then try your hand at box modelling a plane:

1. Go to File > Set Project, create a new folder on your desktop called Spaceship, and when it prompts you to do so, create a MEL workspace. (MEL simply refers to the scripting language that underpins Maya.)

2. Select the Polygon Menu Set.

3. Create > Polygon Primitive > Cube (or Cylinder, depending upon the type of fusilage you prefer).

4. In the Channel Box set the subdivisions for height, width and depth to 10.

5. Use the Scale (R) option to stretch your cube’s length along the Z axis.

6. Hold down the RMB and select the Faces selection mode.

7. Double click on your Selection tool to bring up the Tool Settings window and turn on your Symmetry (Object X, it will be different if you stretched your cube along a different axis than Z).

8. Select several faces along the middle of the sides of the plane and use Ctrl-E to Extrude the wings.

9. Select faces behind the wings and Ctrl-E to extrude horizontal tail fins

10. Turn off Symmetry, select a short row of central faces on the top rear of the plane, and Ctrl-E to extrude a vertical tail fin.

11. Select a rectangle of faces on top of the plane, and Ctrl-E to extrude a cockpit.

12. In the Tool Settings window, turn on Soft Select.

13. Select the faces at the front of the plane and use the Move tool to pull out the nose.

14. RMB and select Vertices selection mode.

15. Tumble around the ship to front, side and back views, selecting groups of vertices on the wings and then the cockpit (turning Soft Select off and on where appropriate) so that the wings are swept back and the cockpit turns in.

16. Cycle through 1, 2 and 3 to look at the smooth mesh preview. Take note if there are any pinching or knotted areas: this indicates you allowed vertices to overlap during modelling. It is possible to repair these using other tools, but much easier to avoid them, and sometimes best to just start again!

17. Make any final manipulations to the geometry.

18. Click on Mesh > Smooth.

19. File > Save your Project.

SAVING & LOADING SCENES

You can save a scene using the Status Line command, or by going into the File > Save (Ctrl+S), or File > Save As (Ctrl+Shift+S) when you wish to save a different version.

However, as you work on complex projects you may find you want to save regularly in case of problems, in which case you can use Increment and Save (Ctrl+Alt+S). This will save the file, but add a number to the file name so that you can return to different iterations of your saved work.

You can save a Scene in one of two formats: Maya ASCII (.ma) or Maya Binary (.mb). The manner in which you save a scene does not change its appearance, only the format in which it is saved.

A Maya ASCII file converts your model and scene into a series of text commands in the standard ASCII character codes (i.e. alphanumeric characters), which means you can open it in a text editor such as Notepad or Wordpad. If you know what you’re doing, this could allow you to repair a corrupted file.

A Maya Binary file has all its text components stripped out and is saved as numeric values. This makes the file smaller but unable to be opened in a text editor. This is the default method, and perfectly fine unless you know enough about MEL scripting to repair a file.

OBJECT HIERARCHY AND PARENTING

Window > Outliner shows you all the objects in your Scene. By default you will have four cameras as well as any objects you have create (in the example below there are two cubes, one on top of the other: pCube1 and pCube2).

• If you double click on an object you can rename it.

• If you MMB click on an object and drag it to another object, you can make it a child object.

• You can create a new group by selecting multiple objects and Ctrl+G

• You can ungroup items by selecting an item and pressing Shift+G.

LAYERS

You should make a point of using layers during a Maya project. This is a simple as selecting an object and clicking on the right hand layer icon with the sphere, which will add those objects to a new layer. The other icons let you move a layer up and down, and assign a selected object to the selected layer. You can click on the icons next to a layer to make it visible/invisible, or set it as a transparent or reference layer, i.e. a layer that is visible but not selectable. You also can double click on a layer to rename it or assign it a colour etc.

Once you have figured out how to create basic polygons, you want to streamline the process and explore other tools and aspects of modelling workflow.

There are a range of other polygon editing tools. Particularly useful is being able to use Reference Images, to Duplicate objects, reset an objects Pivots and Parents, as well as a host of other Mesh Edit and other editing tools, as well as lattice and non-linear deformers.

PIVOTS AND PARENTING

When we rescale or rotate an object, Maya does so relative to its pivot point. Usually this is the middle of an object, but sometimes we need to move it. To do this, simply press D or INSERT, and you can move or rotate the pivot.

The following object has its pivot located first at its centre, and so rotates around it, and then at its bottom edge, and so flips around that point when rotated.

ACTIVITY: Model a Low Poly Scene

1. Model a simple low poly rock by creating a sphere and using the sculpting tools to deform it.

2. Model a simple low poly standard box tree by creating a cylinder for the trunk and a sphere for the foliage.

3. Model a simple low poly pine tree by creating a cylinder for the trunk, adding subdivisions, and rescaling these out to create the layers of branches and needles.

4. Model a simple low poly tree with multiple roots and branches by extruding some faces along an EP Curve, adding spheres for foliage, and sculpting the foliage with a sculpting tool.

5. Model a simple low poly hilly terrain with a riverbed by creating a plane and using the sculpting tools to add 3D textures to it.

6. Model a simple bridge by creating a cube, and a mix of extruding, bridging, and duplicate special.

7. Duplicate, group and arrange objects into a scene in an orderly manner.

8. Save your scene files and copy them to a portable drive so that you can access them later on another machine. (You should take note of the version of Maya you are using.)

5. The Viewcube shows you your current camera angle, and, when you click on it, lets you choose a new camera angle. If it isn’t visible when you load Maya it may be for two reasons.

a) It is not turned on: simply click on Display > Heads Up Display > Viewcube.

b) From Maya 2016, if the view panel’s renderer is set to Viewport 2.0 the ViewCube will not appear. If you can’t see the viewcube, click on the View panel’s Rendering menu and select Legacy default Viewport or Legacy High Quality Viewport.

6. Hotbox. If you hold down the space bar you can bring up the Hotbox, which shows every Menu option for the main Menu sets. Click and hold the mouse bar on a menu option to view it.

If you find the Hotbox overwhelming you can customise it by holding the space bar, clicking and holding down on Hotbox Controls > Hotbox Style, and choosing Zone and Menu Rows, Zones only or Centre Zone only to alter which menu options appear.

7. Hotkeys: You can check and/or change the Hotkeys by going to Windows > Settings/Preferences > Hotkey Editor.

8. Shelf editing: You may wish to create your own shelves with customised commands that don’t have short cuts and/or which you want to use regularly. To do this click on the cog icon to the left of the Shelf panel and bring up the Shelf Editor. This lets you edit the existing Shelves, or create your own Shelves using icons for any available function in Maya.

• Quad Draw Tool (to retopologise a mesh for animation or game by reducing/increasing polycount)

• Compute Guide to Basic Character Creation in Maya (1:45:40)

• Maya Animation Tutorial for Beginners (1:02:19)