I am building a 3D flower mesh through a series of extrusions (Working in Unity 4 environment). For each flower there are splines that define each branch, petals, leaves etc. Around each spline there is a shape that is being extruded along that spline. And a thickness curve that defines at each point in the spline, how thick the shape could be.
I am trying to animate this mesh using parameters (i.e. look towards sun, bend with the wind).
I have been working on this for nearly two months and my algorithm boiled down to basically reconstructing the flower 'every frame', by iterating over the shape for each spline point, transforming it into the the current space and calculating new vertex positions out of it, a version of parallel transport frames.
for each vertex:
v = p + q * e * w
where
p = point on the path
e = vertex position in the local space of shape being extruded
q = quaternion to transform into the local space of the p (by its direction towards next path point)
w = width at point p
I believe this is as small of a step as it gets to extrude the model. I need to do this once for each vertex in the model basically.
I hit the point where this is too slow for my current scene. I need to have 5-6 flowers with total around 60k vertices and I concluded that this is the bottleneck.
I can see that this is a similar problem to skeletal animation, where each joint would control a cross-section of the extruded shape. It is not a direct question but I'm wondering if someone can elaborate on whether I can steal some techniques from skeletal animation to speed up the process. In my current perspective, I just don't see how I can avoid at least one calculation per vertex, and in that case, I just choose to rebuild the mesh every frame.
