Pheonix FD ocean Texture - Masking

[BBHead]

Hi Guys,

I am doing an ocean scene for a project I'm working on. I want some white foamy peaks on the tops of each wave. I have come up with a solution that gives me ok results(see attached test image). I am basically using a displacement modifier on the plane. Its displaced with a noise map.
I then take the same noise map and adjust the output color map to give me a mask for a blend material. With a ocean material as the base and a white noisy material as crest of wave.

Here come the questions

1. Can you create a mask from a phoenix FD ocean texture map? Render texture and convert to give me a mask I can use?
2. it I want to generate foam/spray from the crests can I have plane emit particles from the high points/crests using a mask?
3. Or is there an easier way of doing this?

This is for a still by the way.

Thanks Guys!

Looking forward to see feedback!

Michael

[Ivaylo Katev]

you can use a copy of the ocean texture set in scalar mode (unchecked vector mode) , the proper level adjustment is a bit tricky, because the result is not 0-1 range, but in scene units, see the attached scene.

[BBHead]

Hi Ivaylo,

Thanks ever so much for the response. Is there any logic/steps to the level adjustment? I have tried replicating what you have in your scene with much higher wind speed but am getting not so good results.
Also could you tell what the phoenix fd sim object is doing in the scene? Pardon my ignorance as I'm still learning the ropes.

Michael

[Ivaylo Katev]

yes, as i said the texture result is not a color, it's intended for displacement and it is in scene units. in the attached scene the wind is 2 m/sec and this produces waves about 0.2-0.5 m in height. the scene units are cm, so you have to multiply by 1/20 to have value about 1 for the highest waves. to control the white part i'm using the level offset , but better use output texture instead it, because the behavior of the offset is not intuitive and perhaps will be changed in future. the output texture allows directly to use curve for better control

[BBHead]

Hi Ivaylo,

When you say output texture I assume you mean render to texture?

Michael

[Ivaylo Katev]

no, there is a map called "output" that can modify the colors of any underlying texture , by default the most max textures have it embedded, but the ocean texture does not have it

[BBHead]

Ahh I see!! Thanks for everything. You have been very helpful!

I was hoping you could also clarify what the phoenix fd sim object in the scene you provided was doing?

Thanks again!

[Ivaylo Katev]

it does nothing, just a fast way to have displaced object, otherwise i have to set vray displacement over a geometry.
btw, if you have no projects in short term, we are planing to include automatic foam map for the ocean texture, so you will be able to use it directly.

[BBHead]

Hi,

That sounds awesome! When do guys expect to update Phoenix with this feature?

I have attached my result for ocean shader. Its a combination of technique you have helped with and some mix maps.

Now I just need to figure out how to get some spray coming up off surface.

Michael

[Ivaylo Katev]

phoenix source has the ability to use maps to modulate all the channels, you can use second large low res simulator and emit some smoke or particles using the first simulator as emitter geometry and the foam mask as source mask.

[BBHead]

ok great! I'll give that a try. Thanks again.

M

[BBHead]

Hi,

I have been rather unsuccessful with getting the first simulator to emitt particles with mask in the large low res simulator. I would really appreciate some help if possible.

Michael

[Ivaylo Katev]

i suspected that it's not so simple. the first problem arising in my mind is that the ocean extension is built only for rendering, so you can't use it for the second simulator. this is valid for vray displacement as well, so you can use it neither. the only solution as i see it is to use not the extension, but the simulator's surface itself.

[Ivaylo Katev]

well, in the attachment you can find a simple setup of this.
you have to simulate the ocean simulator first, then you have to run the mist simulator (the thin one)
the mist simulation works VERY slow, because every frame it updates the ocean geometry and voxelizes it, and because it uses the max wind force that is written far ago in the single core ages. i suppose you have to make multiple tweaks until the result is good enough, and every test will be slow, so be ready for hard times. the water is shaded by a test material that shows the emitting zones, replace it with normal water material when you are ready with the tests.
hopefully in the next release there will be a tool that makes this automatically with no user efforts. if you have time, you can wait for it, it's very probably that it will be in the nightlies in few weeks.

edit: the smoke dissipation in the scene is set to 1, but this is too strong, you have to tweak it in order to obtain the desired mist length. dissipation 0 produces long tracks of mist, 1 produces too short mist, it's somewhere between 1 and 0.

[BBHead]

Hi,

Was just wondering if this functionality has been added or soon to be added?

"hopefully in the next release there will be a tool that makes this automatically with no user efforts"

Michael