Fluids

Ive been looking into other methods and one that stuck out was using maya fluids. I have been researching using the internet but also purchased a book called Mastering Autodesk Maya 2011 by Eric Keller which has a lot of good information about fluids.

Maya fluids uses emitters and containers to emit a fluid or particles that is bounded by the container.

I started by trying to test out the fluids by creating a 3D container and adding a emitter to it. I then adjusted the settings to make the particles dense so that they would look more like liquid than a gas. I played around for a long time and kept tweaking the settings to get the desired effect. The first problem that I ran into was that the particles kept going upwards. I managed to rectify this by adding a gravity field so that they would move downwards and look heavy, in the same way that water does.

It took a long time to keep tweaking the settings and replaying the animation because every time I tweaked, I had to re-simulate the animation. When simulating, you cannot start playing from say frame 100 because then the simulation will only start from there. You have to play from the beginning to make the simulation play correctly.

I quickly realised that my computer could not cope with fluids and it took an hour just to simulate 100 frames.

I tried other techniques to get the simulation to quicken such as changing the animation settings to play every frame and even tried to bake the simulation so I could at least play it back once to see what it looked like but this did not work either. Eventually my computer and Maya just kept crashing after about 150 frames and slowed my workflow down to a snails pace.

This was the last frame that I ended up rendering as I had no hope of waiting for more frames to simulate.

There are multiple problems with this:
1. It looks more like smoke than water
2. It is still not dense enough
3. It takes far too long to simulate and render
4. It uses an emitter which is going to be hard to incorporate into the scene
5. To get the emitter to fill the container enough to make it look like a river would take far too long.

I tried to tweak the settings a little bit more by changing the colour to an obvious blue and making the container really small so that I could get at least an idea of what it could look like. This did not work either as Maya just crashed and now would hardly simulate 50 frames.

Knowing there was an obvious problem with this, I tried to see if it was the software of hardware that was making it crash. I did a fresh install of Maya and even tried to upgrade to 2012 but the out come was always the same - Maya would slow down and eventually crash.

I have decided to scrap this idea as even if we could get it to look convincing, it would take days if not weeks to render just still water let alone something passing through it. I could not even get to test the scene with something passing through it as the test would probably not be able to render on my computer at all. It would take far too long and too much hassle to keep tweaking to get it perfect and then talk hours upon hours to render, which we would have to use the render farm for before we even see a small amount of results. Maya fluids is just not something we have the power or time to be able to use for this project.

I have had a couple more ideas of how to get convincing water. I am going to look into something called realflow. It allows your to create water and movement within water. It is used within the industry and seems to give some really realistic effects (Here are some examples of it in action:
http://www.realflow.com/rf_casestudies_portal.php)

Back to the drawing board...

Ocean Shader

I have never used water before in maya so to start with I decide to try out the ocean shader.

I created a very basic river bed scene and added a plane in the middle to act as the water. I know that the ocean shader works very well when it is used for oceans but I wanted to see if I could create a river using it.

I searched around to see if you could use the ocean shader and have it react to objects moving through the water but this soon came up blank. I then started to think that at some point the river would be in the picture before the animals would cross it so this could be a good use for the ocean shader.

I didn't use any tutorial but started to play around with the settings and rendering a single scene to see if th waves were how I wanted them. The main strings I played with were:
Scale
Wave speed
Num. Frequencies
Wave Dir. Speed
Wave Length Min
Wave Height
Wave Peaking

Changing these settings seemed to help me achieve the effect I wanted but it still looked too much like a ocean cropped down to fit between the two banks.

This was the test I managed to achieve firstly:



The first video, I am not happy with as the waves are too close together to be a river. It does not look natural. The waves are also very slow. So slow that you can hardly see the movement which is not natural given the closeness of the waves. I have adjusted the waves and made them larger and also sped up the waves.

This is the second attempt:



I think this ones is too fast so have only adjusted the speed of the waves to see if it makes it look more natural.

This is my third attempt:



I think that it looks ok but I still do not think this is the method to use. It will not interact with objects in the water and even if I only use the ocean shader for scenes where the animals are not in the water, it may be hard to match the colour and effect whilst using a different method when they are in the water.

 I have been researching fluids and wakes and will try a few tests using these. I am also looking at a book called Mastering Autodesk Maya with some good tutorials about fluids. Particles are also something I am going to look into and it may be that I would have to use a mix of methods. I think whichever gives the best effect then that would be the one to use but I obviously have a long way to go before I know which method I prefer.

Chosen area

For this project I have decided to look at different water effects. This is going to be a large part of our final film as it involves an ox walking through a river with a cat and rat on its back.

I have decided to focus of the technical side of things as I am good at problem solving and prefer the technical side of things than creative. Im am using my existing skills and resources of my 3D artist magazine collection - with a load of tutorials, and the fact that I love a challenge and love to learn. I have also realised my weaknesses which are that I am not good at drawing and not good at painting. This includes using a graphics tablet and photoshop.

Other people on my team are a lot better at being artistic so I shall stick to my skills and focus on pushing myself in the technical side of things.

The reason I have chosen water effects is that our film is very reliant on it and making these effects as easy as possible will make the filmmaking process a lot easier. It is also an area which none of my team have though about so will be good to get some knowledge of working methods before we start to animate.

I intend to push myself in maya but also other software to find the best solution for our problem. I think I am a fast learner and this will benefit me massively.

Let the research begin!