Modelling an alien

( page 5)

Five: Trimming

Trimming is for creating holes which can be used as points of attachment for additional surfaces. Here a NURBS circle is being projected onto the lobe object from the current view's perspective. The purple circle is the projected Curve On Surface.

Once a Curve on Surface has been created you can use it in Trimming the surface. After selecting the Trim tool, the object is displayed in a dotted white wireframe, and you are prompted to select the portions of the surface you want to keep. Shift click to select multiple areas, the rest is trimmed and disappears.

A trim is not destructive, the trimmed portion is really just hidden. It can be untrimmed later. To create the tube that extends from the lobe, a curve is created in top view. The original projection le is duplicated and scaled down and then extruded along the curve.

Maya's Fillet Blends are really powerful. We can attach this new tube object to the lobe object using a blend. The trim edges and end Isoparm of the tube are selected in turn and the blend is created between them. The result looks like one continuous, fluid shape.

Because of Construction History we can go and edit the extruded tube with the blend in place. By selecting the Extrude node in the Channel box and typing the [T] hot key we can access some addition manipulators for the Extrude that control the scaling and twist of the extrusion. Clicking on the manipulators and dragging causes the extrusion to change in real tie, and the blend updates too.

Another tube is attached to the band object below using exactly the same methods above. By scaling both the trim curves and the extrusion profile we were able to fatten up the tubes a little more. Once you've got used to working with Construction History, it's hard to go back.