Procedural Modelling

The aim for this project is to be comfortable with making digital asset in houdini. I have experience creating them in school but I never got the chance to create more complex asesst. For this project, I have decided to create a new york apartment building as an asset.

I did some research before starting on my digital asesst. From what i observe, all new york city apartment building have a similar look to them. They all have a balcony or emergency exit at the front of the buildings. Also some of them have borders between each floor and some do not.

So my aim for this project was to create various different look to each building. I want this asesst to be able to generate similar but different looking apartment buildings.

Below is a WIP version of my asset

I will improve on the first floor of the apartment on my next WIP. Planning to add railings on the stairs and control to adjust the number of stairs.

Whirlpool

To start out on this project, I decided to do my research and see how other artists approach on doing a whirlpool.
I have conclude that most of the artist have about the same approach.

1st Approach

One way of the simplest way of doing it is to use a tube and have it animate in a rotation. Then use the vortex force attribute node in sops so we could later use it dops.

This technique was showing result but i was satisfied with the result, I wanted more control and the water to look like its been sucked downwards.

2nd Approach

So I decided to do more research. Researching was really the key on how I got to achieving this effect.
My research extended to tornado. To my knowlegde, tornado and whirlpool are pretty similar in terms of the movement of the particles. Both are rotating towards a downwards spiral direction.

I started to scatter particles on the inside the tube and orient the normal direction in vop sop.

I use volume from attribute node to convert the particles to volume to import to dops so that the smoke will be advect the particles.

Now I am getting somewhere. The flip fluid now seems to have more movement and it is not just affecting the middle particles. The particles are rotating however it is the constant. If I were to apply more value to the force, it will just push all the particles upwards.

Result

I am aware that this effect can be made using the grid to make it look like a whirpool. But I wanted more movement to the particles and whitewater. So I decided to use flip fluids.

There are 2 ways I made this. Scatter points in a geo and point the normal to where you want it to be.

The second way is to do it in a volume vop using the same approach to the vopsop. Give the x and z a negative value and use cross product to get the result.

I use a volume node then volume mix 2 volume vop to get a tube shaped volume. I was having problems with the shape being a box as the flip fluid was showing sharp movement when its starts to rotate.

I got lots of help from the forum at odforce :)

Final Flipbook

After many weeks of doing this mini whirlpool, here is the final flipbook. It might not be scientifically accurate but i think adding a bit of the waves gives it more movement and volume to my flip fluid. :)