Graphics Programs Reference
In-Depth Information
Now that we've turned on our projection cage, I'll explain
what this “cage” does. Since we are trying to grab details off
of our high-polygon model and put them into our low-polygon
model, Max needs to know how far out and at what angle to
grab the details. If the high-polygon model passes through this
shaded cage, we know that we're not going to get that portion
of the high-polygon model in the normal map. This is why I
like the shaded cage—you can easily see when things pass
through it.
Expand the Projection modifier and click on Cage. With
the Vertices sub-object button clicked, select all of the verti-
ces that make up the cage. Pull them forward until none of the
high-poly details pass through the shaded cage.
Note:
While editing the cage you may only move vertices.
Polygons and elements may be converted into vertices to
be moved but may not be moved themselves.
That's all there is to using the Projection modifier on a simple
rectangle.
On a more complex model you could use the Push setting.
This works just like the Push modifier but on the cage alone.
Autodesk has added importing and exporting cages in Max
2008. This is an excellent feature. While there isn't any reason
you would want to use this on our simple plane, you could
export the cage if you were working on a complex object like a
character. This basically clones your low-poly cage and makes
it physical geometry. At this point you can modify your cage
using the modeling tools, which is handy because you'll have
access to all of the Loop, Ring, and other selection tools!
You may not change the number of vertices, cut edges, or
connected edges, as this will change the topology of the cage,
and you won't be able to re-import the cage.
After you're done making changes, click Import… and
then click on your cage geometry. This will copy the vertex
positions of your cage geometry and make them your cage. An
excellent little speed booster for adjusting cages.
