visual effects

This week I learned more about working with VOPs in Houdini – a powerful tool to manipulate point attributes. Using this we can create water droplets on a surface by tweaking attributes of scattered points of the surface geometry . Attributes such as position, normals, colour and other custom attributes.

To create the water droplets we will basically scatter points of a geometry on which we want to create the droplets. Using copy to points node we can copy tiny spheres to replace the points. To make the spheres look like droplets we are going to add smaller spheres on top of each sphere, combine them and then smoothen them out. This is where we will be heavily relying on point VOP nodes.

To create a pscale for the spheres. Using a simple noise function we can assign random sizes to the spheres.
To create smaller spheres on top and move them along the surface upward. This can be achieved using vector functions.
- Cross product between each point’s global y direction and it’s normal
- Cross product between the resulting vector and the point’s normal
Displace the smaller spheres on top by moving the new vector a little away from old points.

Had so much fun just rendering with different geometries and scatter amounts.

So, looks like I’m in love with Houdini, as I am spending a lot of effort on Houdini projects. I took up some tutorials on digital tutors and learnt the art of fracturing in Houdini.

Off the shelf tools are so handy to use if you want to create a scene with a simple breakable object but there’s a lot more for us to learn about the fracture dynamics building blocks.

So I used a box geometry with wood material. The fracture parts are amde to looks long and sharp by adding a transform node after the fracture node. So the pieces are scaled along the y axis to look more realistic as like wooden shards.

Here’s the screenshot of my Box SOP network