Ocean shader

[bigbossfr]

Hi Vlado,
My friend tried to bake the hotOcean into a vector displace map but he is unhappy with the results : the bake is done by normalizing the displacement in x,y,z ; but it seems the displacement in the u,v directions are too high regarding the displacement along N. Is there a documentation about how to generate vector displacement maps ?

We want to try to recompile HOT for Vray, but we don't know what we must to output for vector displace.

[jstrob]

Hot is a very nice shader, would be great to be able to render displacement in vray! For 3dsmax too!

[jstrob]

Hi there,

does anyone have a solution for something like the Dynamic Buoy that Maya's Ocean has,
so I could have a boat on the V-Ray Water that interacts with the waves?

If you output the displacement to an animated map, you could then modify this displacement map with a wake texture created in real flow or maya. You can render this texture by mapping a ramp that goes from back at the bottom and white at the top.

[bigbossfr]

Hi Vlado,
My friend tried to bake the hotOcean into a vector displace map but he is unhappy with the results : the bake is done by normalizing the displacement in x,y,z ; but it seems the displacement in the u,v directions are too high regarding the displacement along N. Is there a documentation about how to generate vector displacement maps ?

We want to try to recompile HOT for Vray, but we don't know what we must to output for vector displace.

Yep,
My coworker doesn't understand what is the good value and range to create a vector displace...?

[vlado]

V-Ray has two options for vector displacement, 0.5-based and 0-based; it will probably be easier to use the 0-based displacement mode - it is called "Vector displacement (absolute)" in the V-Ray Displacement control attributes. (Note that if you are baking to texture maps you might need to enable negative shader colors for the File node.) The values represent displacement in normalized (u,n,v) space, i.e. if displacement amount is set to 1.0, then a change of 1 in the red texture component (when using RGB 0 to 1, rather than 0 to 255) would correspond to a displacement of 1 scene units in the U direction, a change of 1 in the green channel would correspond to a displacement of 1 scene units in the surface normal direction, and a change of 1 in the blue channel would correspond to a displacement of 1 unit along the V direction. The "no displacement" value is 0.0, 0.0, 0.0 for the red, green, blue components.

Best regards,
Vlado

[duran]

Hello I am the co worker using houdini, and I am using the Hot to generate vector displacement maps.
I am using the normal vector displacement mode (not absolute), I think for this one, the no displacement value is at 0.5 0.5 0.5 like you said.
But I think in this mode, the vector displacement is (u,v,N) <--> (r,g,b) and not (u,N,v), am I wrong ?

thanks

z

[vlado]

Hello I am the co worker using houdini, and I am using the Hot to generate vector displacement maps.
I am using the normal vector displacement mode (not absolute), I think for this one, the no displacement value is at 0.5 0.5 0.5 like you said.
But I think in this mode, the vector displacement is (u,v,N) <--> (r,g,b) and not (u,N,v), am I wrong ?

It depends on which vector displacement mode you are using in V-Ray; the "Vector displacement" one behaves similar to what you describe (no displacement is 0.5 0.5 0.0 and the red/green values are scaled twice down); the "Vector displacement (absolute)" mode behaves as I described and matches what is produced out of Mudbox.

Best regards,
Vlado

[duran]

Ok the shading network works well now, thank you!

[timdog]

Im on a suicide mission and sniffing on the possibilities to compile HOT for maya myself but where do I start?

Is there any free c++ compilers suitable for this?

[t.petrov]

timdog:
It depends on the Maya version you're trying to build the plugin for.
Most versions require different compiler and if you build the plugin with the wrong compiler it won't load (most of the times).

[timdog]

Maya 2013 64 bit windows?

[kimgar]

No, but there is a free plugin that generates a water patch based on the same algorithm somewhere on maxplugins.de

Best regards,
Vlado

vlado, are you referring to HOT4MAX, or did i miss a magic plugin?

[t.petrov]

timdog: Then you should look here: http://docs.autodesk.com/MAYAUL/2013...ion/index.html

You need Visual studio 2010 sp1. I'm not sure if the compiler in 2010 express edition (this is the free version) will be able to compile it, probably it will.
Also you can get the compilers with the Windows SDK, but I'm not sure about the details. But using the compiler from the command line will be tougher.

[timdog]

Ok thanks!

[timdog]

Ok, an update. Did a test render based on the HOT library(Houdini Ocean Toolkit).
With help from Nico Rehlberg I was able to compile and output HOT data to Vray for Maya.
Right now Im using Vector Displacement and also a "foam map" (Eigenvalues<0) that indicates where the wave breaks.

Video 1 shows a HOT ocean surface with water shader and simple foam.
https://vimeo.com/49128478

Video 2 shows the same surface upclose with simple shading. Note the waves where it breaks/inverts.
https://vimeo.com/49128479

Technical stuff:
Im still trying to figure out what to include in the final Vray shader.
Useful stuff like the "Eigenvalues" indicates where the wave breaks, but there also seems to be some "foam vectors", Eplus and Eminus.
Any Tessendorf experts or creative individuals that have any idea what these can be used for?

Saw some blender guys digging in on the Iwave solver to get reflecting waves.
Can this be combined with HOT/tessendorf??

I think Maya Ocean optimize ocean displacement by outputting all the fine details with bump maps.
Can this be a good idea here aswell? (all waves shorter than x::bump maps)

To be continued...