2013年11月22日星期五

VIZA626 Generative Art--- Final Animation




For my final project. I want to continue polish my second project, the growing tree, to make it into a complete short animation. I kinda of changing my mind that I want the tree to grow out of flower instead of leaves, because that is more aesthetically appealing to me :)

The conceptual and aesthetic aspect of my final project is similar to my project 2. So here, I will focus on the technical challenges I have come up with in this project.

1. how to replace a simple leaf geometry with a complicated flower geometry.
I build the cherry blossom model using procedure modeling technique in Houdini. The network is showing below. This flower consists of two separate parts: pistil and petal.

 For the flower petal. I first cut off curve node, use skin node to form a mesh, then apply twist node onto that mesh. The advantage of making flower in this way compared to just import a OBJ file is that: we can control the twist amount in our L-system to make procedure animation. Here is an example:
Twist strength set to 100:(flower bud)
  Twist strength set to 50:(fully open)


2. how to control the procedure animation of flowers
In the L-system documentation, I found an interesting function, "stamp". In Houdini we know we can set a stamp value in copy node and the reference that value in the network, so in that way, we can make a slightly difference to each of copied object . L system support up to 3 stamp variables, we can use that variable to track the generation number of each flower and make them open at proper time.

Turtle codes I wrote in L-System:



3. rendering issue
Well, I turned on subsurface scattering, and set up like 15 lights? (= =) in shot in order to get a good rendering result.

Lots people ask me why the flower opens from the tip of branch to the root , the theory is:  the further a flower is away from main truck, the easier it is to absorb solar energy.

Here is some test video I current got:

combined with the render result I had before: