CG Form - 3D Modelling with Lightwave

Render Sub-Patch Level

I'm always amazed at how simple the geometry for some objects is. Converting to a Sub-Patch and surfacing can make a huge difference. Click on the image to the right to see the 'Before' and 'After' stages.

Also important to note is the 'Render Sub-Patch Level' (in Layout) which can be found in the Object Properties panel. This lets you adjust the resolution for each Sub-Patch object in your scene before the final render.

Topology

Before you begin the modeling process, give some thought to the basic structure of the object. Work it out on paper if you need to, and think about the topology of the model and what kind of segment structure is needed for the initial primitive.

Keep it simple and block out your object using the Bevel, Smooth Shift, Knife and Extrude tools. It's important to work with the Low-Poly mesh as much as possible.

See Also: Fingernail Modeling Tutorial

Blocking Out

Here's one example of basic topology for a human character. Keep in mind that it's much easier to control the flow of a low-res mesh. So work with it as much as possible, pushing Points around to get the basic shape, before you begin to add detail.

Basically there's two approaches to Box Modeling with SubPatches:

The first approach is to work with Polygons, previewing development in SubPatch mode (using the Tab Key to toggle back and' forth). This is followed at the end with a lot of tweaking in SubPatch mode and helps to keep a cleaner mesh.

The other method is to work primarily in SubPatch mode. This method relies more on, Smooth Shifting, Spin Quads and Bandsaw. In the end it's really a personal choice.

Other Considerations:

Whichever method you choose it's a good idea to get into the practice of planning out your model on paper. Do some sketches and concept art, rather than just trying to wing it as you go.

Also worth mentioning is to model with details, such as arms and legs, stretched out in a linear fashion. Worry about setting the pose once you're rigged and ready to animate.

Extrude & Lathe Tools

The Extrude Tool works with SubPatches, but you need to follow a few simple rules: Always flip the Poly Normal before you Extrude. Then when your done, delete the extra Poly created at the start point and remember to 'Merge Points' or you'll end up with a mess when you convert to a Sub-Patch.

If for some reason you get an error message when converting to a Sub-Patch, make sure your in 'Polygon Selection Mode' and press the 'w' key to bring up the Polygon Statistics Panel. From there you can easily identify, select and deal with the offending geometry. i.e. Anything other than 3 or 4 sided Polygons.

Clean Mesh

A basic rule to modeling is to only use as many Vertices, as are necessary to hold the shape of the object. Having said this, you need to take care to avoid the temptation of over-stretching a mesh, when pushing Points around in SubPatch mode.

Otherwise you can end up with a confusing mess of overlapping Faces, when you toggle SubPatch mode off. A better option is to model in the actual detail. This can give you the same end results but without the mess.

If your wondering how far you to push it, a good option is to turn the Control Cage on in the Display Options panel. This will give you a visualisation of what's happening to the mesh.

Symmetry Mode

When modeling in Symmetry Mode, any changes made to the +X side of a symmetrical object will be reflect in the -X side.

This is useful when pushing Points around on a base object but it doesn't work on all axis or with non symmetrical sections of an object. It also doesn't work with things such as the Knife Tool. The object doesn't need to be entirely symmetrical, just the sections you're working on.

Note: Before you begin, press the 'F2' key to centre the object. Then activate Symmetry Mode once it's centered.

Set Value

If you cut through an object with the Knife Tool (in a Wireframe View) it creates a ring of Points through all intersecting Vertices. You can then easily 'Volume Select' and delete one half of the object. This allows you to work on the remaining side and use the 'Mirror Tool' to replace the missing half.

The Set Value Tool is useful when working on symmetrical objects, such as a head.

To save time delete one side of the head and only work on the remaining half. When your finished making changes, 'Volume Select' the open ring of Points and use 'Set Value' to make sure the Points are perfectly aligned along the X axis, before you Mirror the remaining side into place. Connecting Points should Merge automatically.

See Also: Half Kill http://www.flay.com/GetDetail.CFM?ID=1200 This is an Lscript for Killing one half of a Symmetrical Object. Deactivate Symmetry Mode before running the script or you'll kill both halves.

See Also: Symm_X_Tools http://www.flay.com/GetDetail.CFM?ID=1740 A couple of extra tools for speeding up the Mirroring process.

Construct > Subdivide > Knife (K Key)

Sharp Edges

The closer Points are in a mesh the 'tighter' the curve between the two will be. I've just demonstrated how the Knife tool can be used to create a ring of Vertices. Of course this could also be used to sharpen the edge of a SubPatch object.

You can also use 'Smooth Shift' without moving the geometry, to create tight, sharp edges in a SubPatch model.

Organic modeling with SubPatches is a delicate balance between being economical when it comes to adding geometry, but also making sure that you have enough Vertices to produce the required detail, where needed.

Note: Smooth Shift will extrude new geometry along the average of the Normals. This may or may not be what you require. An alternative which provides more flexibility, is to Smooth Shift without moving, and then use the 'Move Tool', to position as required.

Multiply > Extend > Smooth Shift (F Key)

SubPatch Weights

SubPatch Weights can also be used to create sharp edges. These effect Points or Polygons.

Note: Although this feature is useful, 'Edge Weights' are desperately needed, but not yet featured in Lightwave.

Map > Weight & Color > Weights

Seamlessly Blending Sub-D's and Faces

This technique seamlessly merges SubPatches and normal Polygons, using 'SubPatch Weights' on the connecting Points. It's great for solid/rigid objects, because it's quick and allows you to add odd shaped Polygons when working with a SubPatch object.

The connecting Points are assigned a 'SubPatch Weight' value of 100%, which ensures that they maintain their position.

To avoid pinching at the edges, you also need to double Bevel the main flat Polygon (using inset values only). Some tweaking is needed to ensure that the main Face doesn't overlap the SubPatch sections of the mesh.

Download Model, courtesy of Carmen Rizzolo