Animating Growing Vine

Wile the animation can easily come of as rather complicated it isn’t all that difficult to setup in XSI.

Start by creating a cone from the Get > Primitive > Polygon Mesh menu. Set the Length to 30 and the Base to 0.2. Increase the U Subdivisions to 12 or so and the V to 50. Name it Liana. Click the Center button in the Select menu and in the front viewport, move the object’s center all the way down to the bottom of the liana. This will create the effect of the liana growing from its base rather the center of the object. Since lianas usually don’t grow in perfectly straight lines, you’ll need to give it a bit more organic shape. From the Create > Curve menu choose Draw Cubic by CVs and draw a curve in the top viewport. Make sure you scatter the points a bit on all axes to give the liana a nice three dimensional flow. Now, select the liana object and from the Modify > Deform menu choose by Curve. Pick the curve when prompted. In the Curve Deform PPG start by switching to the Constraint tab and check the Constrain to Deformer checkbox. Switch back to the Curve Deform tab and change the Translation Along Curve so the liana lines up with the curve. Set the Scaling Along Curve to 0 and set a keyframe. Set a keyframe for the Roll parameter as well. Go to frame 100, set the Scaling Along Curve back to 1, the Roll to -145 set another keyframe on both parameters. From the Get > Primitive > Curve menu choose spiral. Set the Height to 20, the End Angle to 3600, the Start Radius to 0.25, the End Radius to 0.15 and finally the Subdivisions to 100. With the spiral selected, from the Modify > Deform menu choose by Curve and pick the same curve that is used to deform the liana. Change the Axis to Z, check the Constrain to Deformer checkbox and change the Translation Along Curve till they line up. Create another cone and make it longer but thinner than the first liana. Apply a Deform by Curve operator and pick the spiral curve. Animate in the same manner as the first liana.

The project files used in this tutorial can be found at:
http://www.Redi-Vivus.com/Caffeineabuse/Animating_Growing_Vine.zip

Adding a twist deformer, or any other deformer for that matter, to the liana before deforming it along the curve will add to the overall appearance of the animation.

Quick tip
To make the liana really stick to the surface of another object you can add a Shrink Wrap deformer to the curve. Change the projection to Closest Surface and lower the Amplitude to keep the objects from intersecting.