Part I, rev 1.1

3D Studio MAX R3 tutorial by Claes Wikdahl, strat@mail.bip.net

In this tutorial I will explain the techniques and concepts behind mesh modeling as I do it. It will be from the basics and up, so that even a beginner can get the hang of it. At the same time, this is all you need to know to create some really advanced models. A thorough understanding of the basic aspects of meshmodeling is essential, so even if you think you got a grip on meshmodeling, read this through and see if you can pick something up.

This first part serves as a reference and basic primer to the mesh object and the Meshsmooth modifier in 3D Studio Max. Part two is a step-by-step tutorial in which we will put the theories discussed in this first part to actual use. I will not go through every single option and feature of this subject, but simply the functions I use frequently in my modeling process.

Mesh modeling

Mesh modeling, or box modeling as it’s also called, together with Meshsmooth is, if you ask me, the fastest and simplest (and thereby the best) way to create organic models. I say this after having used patches, surfacetools and nurbs to build characters. Of course these techniques has other advantages and may be more suitable in some situations, but let’s concentrate on mesh modeling for now. The advantages of this approach are:

• You get results at once – Start with a rough, boxy model to easily “sketch” the right proportions.
• You can without difficulties add more detail as you go along – You don’t have to plan everything in advance.
• You get a multiresolution mesh – Great for speeding up animation in the viewports.
• You get a smooth surface – No more fubar tri-patches.
• No shape is too complex or difficult to model – I promise.

What is a Mesh?

A mesh is made up of the following basic components:

	Vertex – A point in 3d space.
	Face – A surface created between 3 vertices. A face is only visible from one side. Which side depends on which way its Normals are directed.
...and...
	Edge, which really isn’t a component itself but rather a part of a face, is exactly what it sounds like: the edges of a face. Every face has 3 edges. Edges can be Visible or Invisible. Invisible edges don’t show in the wireframe view but can still be selected and are then displayed as dotted lines.

The Editable Mesh

You can create an Editable Mesh in two ways:

1. Collapse stack: In the Modify tab, click Edit Stack and, if you have no modifiers, choose Convert to: Editable Mesh. If you have a bunch of modifiers in the stack, you have to collapse it and then, if it still is not an Editable Mesh, choose Convert to: Editable Mesh.
   
2. Apply an Edit Mesh modifier. In R3 an Editable Mesh and the Edit Mesh modifier have identical functions (except for vertex animation).

    Note: Having Edit Mesh modifiers in the stack increases the file size considerably since the modifier duplicates the geometry.

The Editable Mesh in 3D Studio Max has the following Sub-Object modes:

	Vertex – Select and edit Vertices.
	Edge – Select and edit Edges.
	Face – Select and edit Faces.
	Polygon – Select coplanar faces as set by the Planar Thresh value. Imagine pouring water on a surface and the water is only stopped by sharp angles and, if Ignore Visible Edges is unchecked (default), visible edges. Note: When “counting polygons” in a scene or game you are actually counting faces.
	Element – Select all contiguous faces in a mesh. That is, if two faces share the same edge, they will both be selected.

The first thing you need to do when editing is select what you want to change. This could sometimes become very hard in a complex model. Here I will go through some techniques to simplify the process of selecting. You can Select and Region Select (drag) with the Select-, Move-, Rotate- and Scale Tools.

1.	There are three variations of Region Select (Main tool bar):
		Rectangular
		Circular
		Fence
	Also, you have these options (Status bar):
		Selects within and crossed by region.
		Selects only within region.
2.	To add to your selection, hold down Ctrl while selecting. To subtract, hold down Alt.
3.	You can save your selections! This is very useful when you have managed a complex selection. Make your selection, type a name for it in the Named Selections field (Main toolbar) and press Enter. Whenever you need that selection again, just select it from the list. These Named Selections are local to the Sub-Object mode that you're in at the moment. They will also disappear as soon as you collapse the stack.
4.	Ignore Backfacing (Edit Mesh Selection rollout). If checked, you can only select Sub-Objects that have their Normals facing towards you in the viewport. Try this on a sphere in the Perspective Viewport.
5.	Hide what you don't need to see. You can't work efficient when the viewports are messy. This also makes it easier to make complex selections by excluding geometry otherwise obstructing your view. Simply select the Vertices or Faces you want to hide and press Hide (Edit Mesh Selection rollout).
6.	Soft Selection (Edit Mesh Soft Selection rollout). This new feature implemented throughout R3 is really great. It lets you influence Sub-Objects outside the actual selection to a certain degree. Maybe most useful in the Vertex Sub-Object mode. Here the influence field is represented in color, which makes it easy to see what is going to be affected. The parameters in this rollout are pretty self-explanatory. Use the falloff parameter to change the size of the volume affected.

So, how can you edit your object? First of all, all Sub-Objects can be transformed, that is moved, rotated and scaled. You can also hold down Shift while transforming and thereby clone the selected Sub-Object(s). Transforming objects in the perspective viewport is really a piece of cake in R3 thanks to the new transform gizmo. However, in some situations the gizmo can be somewhat frustrating when you’re trying to move or select something. In this case, just hit x on the keyboard to toggle the gizmo on/off.

If you are working a lot in a shaded viewport, it’s a good idea to enable Edged Faces. Toggle Edged Faces on/off with F4 on your keyboard. This puts the wireframe view on top of the shaded so to speak.

Let’s go on to the individual Sub-Objects.

Vertex

This is where you do most of the actual moulding and fine-tuning by transforming the vertices. The other thing you will do in this mode is welding vertices. This means joining 2 or more vertices to 1, making faces and their edges share the same vertex. Simply select the vertices you want to weld and press Selected in the Weld group located on the Edit Geometry rollout. All selected vertices within the threshold value entered in the field to the right of the Selected button will be welded.

On rare occasions you might need to Create or Break vertices (both on the Edit Geometry rollout). Create is pretty straightforward and Break simply does what Weld does but backwards, splitting the selected vertex into one for each face attached to it.

Edge

You can of course also scale-extrude. This is great for adding more density in the mesh, for example around the eyes of a creature.

Speaking of increasing density, let’s have a look at the Cut function. This is identical to Cut in face Sub-Object mode. Press the Cut button in the Edit Geometry rollout and click on an edge. Now you can draw a line over those faces you want to cut. You don’t have to click on every edge you pass over; you can draw a line all across your object if you want. Click the right mouse button when you’re done or to interrupt the operation.

Try selecting all edges to see even the invisible ones (as dotted lines). Notice that, if you ended a cut in the middle of a surface, additional faces (with invisible edges) are automatically created.

Another valuable function is Chamfer. Select the edges you want to chamfer and drag the spinner to the right of the Chamfer button on the Edit Geometry rollout. Watch out so that you don’t accidentally create overlapping or intersecting faces.

Near the bottom of the Edit Geometry rollout we find some precious (I’m using Words synonym function…) buttons. The first being Select Open Edges. Press this button to see whether you have some unintentional gaps in your mesh, which means welding some vertices to fix, or if you want to select all edges around an eye or a leg socket.

The second button I’m thinking of is Create Shape from Edges. This is practical if you for instance want to model a car window, using splines, to fit perfectly, or you can convert the whole object to splines:

Mesh – Spline - Mesh

Enter edge sub-object mode, choose Edit – Select all (menu bar) and press Create Shape from Edges. In the dialog that comes up check Linear and Ignore Hidden Edges. Exit sub-object mode and delete the Mesh object. Select the Spline object and apply a Surface modifier. Check Remove Interior Patches and set Steps to 0. Apply an Edit Mesh modifier and collapse the stack. We’re back!

In the Surface Properties rollout we have two buttons to decide if an edge should be visible or not. I hope you understand how to use them.

Face

We have already talked about extrusion. One difference from edge sub-object mode is that you can’t Shift-Move a face to extrude it. This will cause the selected faces being duplicated without attachment to its original element. No, you have to select the faces to extrude and drag the spinner to the right of the Extrude button. Another difference is that the actual face being extruded is moved and not duplicated.

Cut works exactly like in edge sub-object mode. See above.

In some situations you might have to create new faces. This is accomplished by pressing the Create button and clicking on 3 vertices in a row, drawing a face. Depending on which way (clockwise or counterclockwise) you draw the face, normals will be pointing in different directions. If you created a face and nothing seemed to happen, the normals are pointing away from your view. Try drawing it the other direction.

While we are on the subject of normals, on the Surface Properties rollout in the Normals group, there is a button marked Flip. This lets you flip the normals of the selected faces, thus deciding from which direction they will be visible.

Polygon and Element

Polygon and Element are only alternative ways of selecting faces. This means editing is identical to editing faces. See above.

Meshsmooth is an absolute necessity to this modeling approach. This is where the magic happens. Without Meshsmooth, mesh modeling wouldn’t be a viable option for hi-res modeling.

Meshsmooth is a modifier that you in most cases apply last in the stack. It does not destroy mapping coordinates or material ID’s from the underlying mesh.

The only parameters I usually change in this modifier are Subdivision Iterations. That is how smooth/dense the mesh will be. You can have different values in the viewports and at rendertime; just check Render Values Iterations and enter a value. Usually 1 iteration is enough in the viewports and maybe you want to increase to 2 in Render Values.

When you let Meshsmooth operate on Polygons (default and what you almost always want) Edge Visibility is of importance. Meshsmooth simply ignores Invisible Edges. (Much like the Polygon Sub-Object mode of Edit Mesh with Planar Thresh at 180.)

I rarely use it but I’m bringing it up anyway: Meshsmooth also has two Sub-Object modes: Vertex and Edge. We can leave edge for now and just mention that Vertex Sub-Object lets you adjust the weight of each vertex in the controlmesh. A higher value pulls the geometry towards that vertex.

A valuable method could be (I don’t use it that much), after applying Meshsmooth, going back to the Editable Mesh and turn on Show end result. This lets you see the object with Meshsmooth active and a wireframe of your original lo-res mesh that is fully editable as usual.

Well, there’s not much to wrap up is there? I tried to wrap it up in the first place. In the next part we will go step-by-step in creating a fascinating creature. If you have any comments on this tutorial or if you find something that is utterly crappy or inaccurate, please mail me at strat@mail.bip.net You can also visit my homepage at http://www.ludd.luth.se/~strat  

 Copyright © 2000 Claes Wikdahl. All rights reserved.