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Mastering
3D Studio MAX R3 |
Generating Geometry with Modifiers
In addition to molding and sculpting geometry at the sub-object level,
there are two modifiers that actually create additional geometry that
can be rendered.
- Disp Approx The Disp Approx modifier changes geometry according
to the grayscale values of an applied material; it does this at the
modifier level, while converting the base object to an editable mesh.
With a noise map, for example, a flat plane object can be transformed
into a striking canyon or a mountainous terrain. These changes are not
seen in the viewport. They are seen only at render time, and can have
a significant impact on your render time due to the processing needed
to calculate the new geometry.
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Top 5 MAX Concepts
Meshing Around: The Difference Between Edit Mesh and Editable Mesh
On the surface (no pun intended), the difference is simple: one
is a modifier, one isn’t. Both have similar capabilities. Why
have two?
Well, before we explain this one, let us recap for the page surfers
who might have just tuned in. An editable mesh is what might be
considered the basic polygonal object. It is the result of a collapsed
modifier stack, has no modifiers on top of it (yet), and has no
parameters. It allows you to access the Polygon sub-object level.
The Edit Mesh modifier is a modifier placed in the stack anywhere
above the base object. It, too, allows you the ability to edit the
object at the sub-object level. So what’s the difference?
The obvious one is that by using the Edit Mesh modifier, you can
edit the sub-object at any point in the stack without having to
collapse the stack. This is good, because if you change your mind
mid-stream while modeling, all you have to do is throw away the
modifier to lose the work you have done. This is not possible when
editing the mesh at the editable mesh level. The other advantage
is control and organization. Using the modifier allows me to separate
my work. For example, if I am modeling a killer whale, I can keep
my tail vertex work separate from my dorsal fin work. I can keep
the pectoral fin face extrusions apart from the tail flipper extrusions.
My work is neatly organized and, at any time, I can revisit the
modeling process and remember what I did.
Then why do the same things at the editable mesh sub-object level?
Well, if you are good, or want to quickly bang out a basic starting
object, you can do it here without the overhead of multiple modifiers.
Remember, at render time, any modifiers in the stack are loaded
into memory with the object. Modifiers are part of the dataflow
and are calculated at render time. The Edit Mesh modifier is the
largest modifier in terms of the memory it takes up at rendering.
Learning to realize when you need control over your mesh vs. when
you need efficient modeling will help you determine which method
to use. Like so many other realms, ultimately, experience is the
real factor here.
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- Lattice Another nifty modifier. Need a building structure (girders
and crossbeams)? Use Lattice. Need an actual globe grid not done with
a wire map material? Use Lattice. Need a quick and dirty radio tower?
You guessed it, use Lattice. Lattice takes the visible (or invisible)
edges and vertices of any geometry and creates a series of boxes and
spheres that replace the faces. You now have a “sub-structure”
for your object!
Editing Sub-Objects
with Modeling Tools
As you become a skilled artisan at the craft of modeling, having multiple
modifiers at your beck and call is fantastic, especially when you know
when and how to use them. But as you gain commanding knowledge of certain
techniques, you might find that multiple modifiers are cumbersome and
confusing. Additionally, your self-confidence as a professional modeler
will bolster new creativity, making you want to try out new techniques.
Sometimes, you really want to work “under the hood”: just you
and the sub-objects. No modifiers. No parameters. Not even a spinner.
This is the world of bare-bones, seat-of-your-pants modeling, where your
every move is recorded only in the Undo history and can be gone in a flash.
Modeling at the mesh level is fun, quick, and requires thinking on your
feet. It is the closest thing to sculpting with a chisel there is in 3D,
because every change you make might be undoable and permanent.
© 2000, Frol (selection,
edition, publication)
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