Fish leaps out of water - help needed

I started making this image:



although pleased with initial results, I have come across several problems which have stopped me from continuing the project.

Firstly, the water droplets are perfectly round. However, looking at reference images of water, there is usually a lot more chaos with variable size drops and white spray rather than droplets. Can this effect be created in the water simulation or are there other ways of doing this?

I have also realised that water motion blur is not supported by cycles yet, and my attempts at rendering a seperate render layer with Blenders internal renderer, to get the motion vectors needed for motion blur in the compositor, have not worked out.

Furthermore, the water ‘sticks’ to the fish as Blenders water simulation does not allow for partial-slip on animated objects.

The shader used on the fish has not really been of concern to me yet as I wanted to figure out if I could even get the water to look like I want it.

Please reply if you have any suggestions or comments on this image.

Thanks in advance.

Firstly, the water droplets are perfectly round. However, looking at reference images of water, there is usually a lot more chaos with variable size drops and white spray rather than droplets. Can this effect be created in the water simulation or are there other ways of doing this?

I don’t have much experience with the water simulator, but I have a idea, why not try to convert the simulation result on a mesh, and you sculp the drops according to how you want them to look, that way you don’t depend to the random options And you have more control from the drops shape.

I have also realised that water motion blur is not supported by cycles yet, and my attempts at rendering a seperate render layer with Blenders internal renderer, to get the motion vectors needed for motion blur in the compositor, have not worked out.

mmm… maybe you could try to use a blur filter on compositor, that allow you continue using cycles for the water, and don’t lose work on that part.

I hope my feedback could be help on some way, greetings!

-José

Hi Jose,

The water simulator actually genereates a mesh for the water for each frame automatically. Therefore I could sculpt the water. However,I was looking for a more procedural way of doing it to create finer detail - maybe a particle system.

maybe you could try to use a blur filter on compositor, that allow you continue using cycles for the water, and don’t lose work on that part.

As the water simulator generates a mesh, motion blur was previously done in the compositor using the Vector Blur node. In the water simulation there is an option to generate these Vectors for the mesh when the simulation is calculated. It is this, which only worked in the Blender internal render and even with this I was getting some unexpected results, which is why I’m looking for an alternative way.

Thanks for the reply, maybe I will sculpt the Mesh as you suggested if I find no other way.

I think the best way to do this would be to use a particle system emitting a group of sculpted water particles of many shapes and sizes… If you mess around altering the velocity settings on the particle system, i’m sure you will be able to re-create the effect you are looking for (I’ve never used a particle system for water droplets myself, but they have worked perfectly for re-creating sparks from flames and rubble from explosions)

You could also add a collision modifier to your fish so the particles stick to it as you want them to.
But i think it may be better to sculpt the water that is sticking to the fish to allow for more creative control.

This is just the way that i would go about it due to the fact that if you use the fluid sim, you need to enable at least 3 isosurface subdivisions in the settings to allow for particles to be generated. Also you would need it to be at a high resolution in order to achieve realistic results, both these factors add up to HUGE baking time. Seriously, i’ve waited hours upon hours for a fluid sim bake to finish.

Either way i wish you all the best with this project, it already looks very good :smiley:

Yes I think Ill definatley sculpt the water seeing as I am only making an image (even though an animation would be cool as well).

Also I was wondering if the ‘fluid’ physics setting for the particle system could be used for the water spray. Ive never used it before.

It definatley can be used for water spray, but like i said earlier it takes a long time to achieve a realistic result. due to the fact that the simulation has to be baked, and for particles to be produced in the simulation you need to enable 3 subdivisions which increases baking time further.