Constraining an Insect Leg ~ Basic Set-Up and Positioning
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CONSTRAINING AN INSECT LEG
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BASIC SET-UP AND POSITIONING
Making the first leg. -
SETTING UP THE RIG BONES
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ADDING THE CONSTRAINTS
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ADDING MORE LEGS
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ADDING MORE LEGS, CONT'D
1. Model a Sphere and extrude a leg segment. I sculpted mine just a little to give the leg a little shape. Make sure that you move these parts off of the y-axis into negative values (in other words, from the front view, off to the left), and the x-axis into positive values (in other words, up).
2. Go into bones mode by hitting the F6 key, or clicking on the bones mode button at the top of your screen.
3. Add a bone that starts at the center of the sphere and goes out to the left past the end of the extruded leg segment. Technically, its ending point should be the same distance as from the center of the sphere to the beginning of the leg segment. Here are my values for this bone:
| Start Pos. | End Pos. |
|---|---|
| -9.91 | -61.2 |
| 18.82 | 18.82 |
| 0 | 0 |
giving this bone a total length of 51.29 cm. Name this bone “R_Mid_Leg1” and assign all the control points of the sphere and the leg segment to it. Make sure that the Roll Handle is pointing upwards.
The basic leg segment and its bone
4. Go back into modeling mode by hitting the F5 key, or selecting the modeling mode button from the top of your screen.
5. Select from the “Tools” menu “Options”. In the “Units” Tab, find the “Paste/Extrude Offset” and make both the x and the y values 0. Click OK.
6. Select the whole model.
7. Go to the Edit Menu and select “Paste with Bones”. Notice that immediately under your first bone, “R_Mid_Leg2” was created.
“Paste with Bones”
8. Go back to bones mode (F6) and select “R_Mid_Leg2”. Go into its Properties by selecting the “View” menu and then “Properties”. Click the “Heirarchy” Tab, and make sure that the “Move Control Points” option is checked on. In the X Offset field, type in the value of the length of the bone as a negative number. In my case, the proper value to type in would be “-51.29”.
The result of having pasted with bones, and moved the second bone to the left.
9. Repeat steps 4-8 twice more so that you have a total of 4 spheres and 4 leg segments.
After all the “Paste with Bones” and moving those bones.
10. Rename the last bone “R_Mid_Foot_Geo”
11 . Back in modeling mode, sculpt the very last segment to look like a short spike. This will serve as a foot. Also, in bones mode, shorten the length of the bone by either pulling back on the tip or, select the bone, hit the ‘S’ key to scale, and scale it down.
12. Finally, make the bones all children of one another and in order, and turn the “Attached to Parent” option on in their Bones Properties.
Reorganizing the Hierarchy of the Bones and having made sure that the bones were attached to their parent bones.
Positioning the Leg
1. Still in bones mode, take “R_Mid_Leg1” and, in the Heirarchy Tab of its Properties, type in “-40” degrees on the Z axis to rotate it by that amount. Make sure that “Move Control Points” is checked.
2. Select “R_Mid_Leg2”. In the Heirarchy Tab of the “Properties” Panel, type in “40” degrees in the Z field. Also do this for “R_Mid_Leg3”.
The model repositioned. Notice that the foot is on the x axis.