When the user interface lists modifiers, it lists them typically by sets. The modifiers are classified into different types or sets on the basis of their functionality. Following is a list of modifier sets in Max.
- Selection Modifiers
- Path/Spline Editing
- Mesh Editing
- Animation Modifiers
- UV Coordinate Modifiers
- Cache Tools
- Subdivision Surfaces
- Free Form Deformations
- Parametric Modifiers
- Surface Modifiers
- Conversion Modifiers
Two commonly used Mesh Editing Modifiers, Edit Mesh Modifier and Extrude Modifier are discussed below.
Edit Mesh Modifier
When an object is converted to an Editable Mesh, its parametric nature is eliminated. However, if you use the Edit Mesh modifier, you can still retain the same object type and its parametric nature while having access to all the Editable Mesh features.
For example, if you create a sphere and apply the Edit Mesh modifier and then extrude several faces, you can still change the radius of the sphere by selecting the Sphere object in the Modifier Stack, and changing the Radius value in the Parameters rollout.
The Edit Mesh modifier provides explicit editing tools for different sub-object levels of the selected object: vertex, edge, and face/polygon/element.
The Edit Mesh modifier is similar in its capabilities of the base Editable Mesh object, except that you cannot animate sub-objects in Edit Mesh.
The Extrude modifier can be applied only to spline or shape objects. This modifier adds depth to a shape and makes it a parametric object.
This modifier copies the spline, moves it a given distance, and connects the two splines to form a 3D shape.
Parameters for this modifier include an Amount value, which is the distance to extrude, and the number of segments to use to define the height. The Capping options let you select a Start Cap and/or an End Cap using either a Morph or Grid option. The Morph option divides the caps into long, thin polygons suitable for morph targets, and the Grid option divides the caps into a tight grid of polygons suitable for deformation operations. The Cap fills the spline area and can be made as a Patch, Mesh, or NURBS object.
Only closed splines that are extruded can be capped. You can also have mapping coordinates and Material IDs generated automatically. The Smooth option smoothes the extrusion.
NURBS is an acronym for Non-Uniform Rational B-Splines. They are the ideal modeling tool for creating organic characters because they have a number of advantages. They are easy to work with, they give you good interactive control, they blend together seamlessly, and their surfaces remain smooth even when distorted. NURBS are superior to polygonal modeling methods when building models with smooth flowing contours such as plants, flowers, animals, and skin.
A NURBS model can be an assemblage of multiple NURBS sub-objects. For example, a NURBS object might contain two surfaces that are separate in space. NURBS curves and NURBS surfaces are controlled by either point or control vertex (CV) sub-objects. Points and CVs behave somewhat like the vertices of spline objects, but there are differences.
A patch is a type of skewable object. A patch object is useful for creating gently curved surfaces, and provides very detailed control for manipulating complex geometry.
When you apply an Edit Patch modifier to an object or convert it to an editable patch object, the software converts the object's geometry into a collection of separate Bezier patches. Each patch is made up of three or four vertices connected by edges, defining a surface. Patches also have interior vertices that you can control, or let the software control for you.
You can also create a patch by applying the “Surface” Modifier on a closed shape object containing 3 or 4 vertices along its perimeter.
You control a patch surface's shape by manipulating the vertices and edges. The surface is the renderable geometry of the object.