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royterr
08-06-2009, 11:38 PM
i am trying to simulate a sea surface by using an ocean texture displacement and a mi_material applied to a plane.
to add the dine detail in weaves i added a fractal bump texture.Now it looks ok but it could me more accurate.
Duncan suggested to use the same ocean texture use for siplacement also for bump. He suggested to increase "num frequencie" and tune the "small wave lenght" height and peak to replace the nice fractal effect. I tried doing this without convincing results:

any ideas on how i can add an accurate ocean texture to bump to make it more accurate?

scene (http://sor.typepad.com/files/fractalvsocean.rar)

http://sor.typepad.com/.a/6a00d8350600cb53ef0120a4cf19de970b-800wi

gianghung79
11-27-2009, 07:00 AM
hi, thank you for your scene, i downloaded your scene anh try to render, but it takes so long time to render, 10 times longer than i use the default ocean shader.

gianghung79
11-27-2009, 07:04 AM
hi, thank you for your scene, i downloaded your scene anh try to render, but it takes so long time to render, 10 times longer than i use the default ocean shader.

royterr
11-27-2009, 04:59 PM
you will have to tune the displacement

InfernalDarkness
11-27-2009, 07:54 PM
I've made decent oceans before using the oceanshader and fractals, simply mixing the outputs with another node or nodes before piping into the mia_material. I'll give your scene a shot and see if I can come up with anything helpful.

YourDaftPunk
11-28-2009, 04:33 AM
Duncan suggested to use the same ocean texture use for siplacement also for bump. He suggested to increase "num frequencie" and tune the "small wave lenght" height and peak to replace the nice fractal effect. I tried doing this without convincing results
How do I reeeeeach these keeeeds??

This is what it looks like when you do what Duncan says, plus a dash of rocket sauce:
http://www.shawnlipowski.com/forumFiles/ocean_texture_settings.PNG

http://www.shawnlipowski.com/forumFiles/ocean_detailed.jpg

scene (http://www.shawnlipowski.com/forumFiles/ocean_detail_02.zip)

Scale is very, very, very important with the ocean shader. It's also important that your smaller waves are not too smooth or small (in height) when they're in the correct scale if you want this look.

it takes so long time to render, 10 times longer than i use the default ocean shader.
As for that mystery, I think it's because Royterr had the numWaves parameter set to 50.

10-16 is usually the range happy oceans live in. At least it was when Bob Ross was painting oceans.
-shawn

InfernalDarkness
11-28-2009, 05:57 AM
I think the rendertimes and calc times were more related to the "Smooth" interpolations in Roy's setup, after playing with his scene a bit. Obviously your setup looks just fine, though! I would have tried Smooth or Spline too, but now it makes a bit more sense...

http://img215.imageshack.us/img215/9641/1205howreachkids2.jpg

YourDaftPunk
11-28-2009, 05:59 AM
I'm so glad someone gets South Park references :)

ytsejam1976
11-28-2009, 12:08 PM
This is my little tips for use mia_material and render ocean
It's only with bumo, but the same use with displacement.
http://www.megaupload.com/?d=8LAFWOPT

on youtube: http://www.youtube.com/watch?v=YgxI4FFBAV4

is without audio, for no problem with my brrrrrrrrrrrrr............. english. :)

ytsejam1976
11-28-2009, 01:45 PM
yes i'm see the strange error. I'm reupload it on rapidshare. Stay tuned

Skoczylas
11-28-2009, 01:47 PM
This is my little tips for use mia_material and render ocean
It's only with bumo, but the same use with displacement.
http://www.megaupload.com/?d=8LAFWOPT

on youtube: http://www.youtube.com/watch?v=YgxI4FFBAV4

is without audio, for no problem with my brrrrrrrrrrrrr............. english. :)

I cant download the file on megaupload. It says that the file "is not accessible" - somebody gets the same error message? Unfortunately the video you uploaded on youtube is at a very low quality :(

ytsejam1976
11-28-2009, 01:49 PM
Now my video after the youtube conversion operation, i'm see good, not low as after my upload it.

Skoczylas
11-28-2009, 02:14 PM
Yes indeed, it looks great now! Thank you for creating this tutorial, it was very interesting to watch! :thumbsup: Whats odd is that it stops so suddenly. You were tweaking the foam and then it was cut off. I wonder why you did not show the final result with the foam.

ytsejam1976
11-28-2009, 02:14 PM
Thank you and sorry but i'm translate your answer soon (for my problem with english :) ) My foam appears well.

http://mayadvance.blogspot.com/

ytsejam1976
11-28-2009, 02:26 PM
http://rapidshare.com/files/313433596/Maya_Mia_Ocean_Plausible.rar.html

here rapidshare link. I hope never problem appear to download it.



P.S. i'm remember you that on my youtube channel the video is ini two parts

Skoczylas
11-28-2009, 02:56 PM
Youre right, there are two parts. Its all good now ;) Thank you.

ytsejam1976
11-29-2009, 05:12 PM
oh wow. Nice one.
Little tips is connect a round corner to Overall Bump with radius 0.1-0.25 to fill a little intersection with ocean. It's connect to ocean material.


yes shawn test have a subdivision approx and usually with displ approxx i'm use subdv approx.

ciao


P.S. on round corner, check on allow different material

Skoczylas
11-29-2009, 05:12 PM
I did a rendertest last night and this is what it looks like:

movie (http://pureimagine.com/tmp/ocean2_15h.001.mov)

Biggest problem are those artifacts i'm getting. I dont know where they come from, but maybe it could be that I need a higher subdivision in my mental ray approximation editor? Maybe I should have used a subdiv surface instead of a simple poly plane like shawn did?

YourDaftPunk
11-29-2009, 06:00 PM
Biggest problem are those artifacts i'm getting. I dont know where they come from, but maybe it could be that I need a higher subdivision in my mental ray approximation editor? Maybe I should have used a subdiv surface instead of a simple poly plane like shawn did?

Looks good. Those artifacts are common with oceans- like a normal is bent the wrong way... Hmmm.

Skoczylas
11-30-2009, 12:34 AM
At first I thought its cause of the low subdivisions of my plane. Smoothing the plane solved the problem for some regions, at other regions it got worse. Also setting the "Min/Max Subdivisions" in the mental ray approximation editor to higher values did not make it better.

So what do you mean with "it comes with the ocean shader"? I cant see any artifacts on your rendering shawn ;)

@Dario: I know the trick with the roundcorners-node. And I also used it once. But at this scene the effect does not show up correctly. I dont know where the problem is.

If someone likes to have a look here is my scene: Link (http://pureimagine.com/tmp/ocean2.mb)

Libor
11-30-2009, 08:26 AM
...well to me it seems like self reflections of the water surface. try turning "visible in reflections" off in shape node ...could help


L.

ytsejam1976
11-30-2009, 10:03 AM
The problem of little triang appears on ocean is a problem that appear in some displacement, like a grass or any other displ approx. It's a slow subdivision number problem. I'm ready for upload a little test render on my scene. Only 2 seconds, sorry :(.
stay tuned.

ytsejam1976
11-30-2009, 10:34 AM
http://www.youtube.com/watch?v=Cp1EPGBohqA

royterr
12-03-2009, 07:12 PM
This is what it looks like when you do what Duncan says, plus a dash of rocket sauce:
http://www.shawnlipowski.com/forumFiles/ocean_texture_settings.PNG

http://www.shawnlipowski.com/forumFiles/ocean_detailed.jpg
scene (http://www.shawnlipowski.com/forumFiles/ocean_detail_02.zip)


Nice!

Now why did you convert the poly surface to asub-d knowing tha MR converts everything to polygons at rendertime?
I noticed that it gives better results then a poly surface with the same number of subdivisions and aproximation editor node,why is that?

the ocean bump looks better than the fractal bump for far and mid distance areas but it looks like gelly in some parts of the foreground (bottom right area). Is there away to make those areas look more convincing? Is that really the best that we can achieve with the ocean texture?

YourDaftPunk
12-03-2009, 08:24 PM
Nice!

Now why did you convert the poly surface to asub-d knowing tha MR converts everything to polygons at rendertime?
I noticed that it gives better results then a poly surface with the same number of subdivisions and aproximation editor node,why is that?


I think sub-div meshes in maya are converted to catmull-clark type where as polygons are converted with the old sub-div methods. It does seem better though, doesn't it?



the ocean bump looks better than the fractal bump for far and mid distance areas but it looks like gelly in some parts of the foreground (bottom right area). Is there away to make those areas look more convincing? Is that really the best that we can achieve with the ocean texture?

I think those areas could use a touch more texturing, but not much. You can push the ocean texture harder, use more tessellation or use another high freq fractal for bump, but only decide that after seeing it in motion with film grain- you may not need it.
-shawn

royterr
12-03-2009, 09:20 PM
I think sub-div meshes in maya are converted to catmull-clark type where as polygons are converted with the old sub-div methods. It does seem better though, doesn't it?


it is!!
i never expected that, there is a huge difference.
i am a bit confused, i thought you could achieve whatever you want with polys (with the right aproximation values). Is t possible to obtain the same results with polys?

YourDaftPunk
12-03-2009, 09:41 PM
I think you can make poly meshes into ccmeshes by adding a mental ray specific flag, but I'd have to google it, and I must go home! If someone knows, please chime in.

Skoczylas
12-03-2009, 09:58 PM
Well I didnt expect it too, but there is obviously a difference. Not only in kind of 'quality' also it renders about 30% faster when I convert the polyplane to subd.

Edit: Its more like 10% faster

I'm going to render a sequence to see if it helps stopping those artifacts.

royterr
12-04-2009, 02:37 AM
I think you can make poly meshes into ccmeshes by adding a mental ray specific flag, but I'd have to google it, and I must go home! If someone knows, please chime in.

i think they are turned on by default:
http://www.pixelcg.com/blog/?p=386

mercuito
12-06-2009, 07:50 PM
ccmesh is on by default when using subdivision approximations. However there is a dynamic attribute to turn it off.
addAttr -ln "miExportCCMesh" -at bool mentalraySubdivApprox1
Most of the time I always turn it off. ccmesh is a bit faster and more memory efficient, but it pretty much always creates seams, and i've had it do super weird stuff to the uvs.

royterr
12-09-2009, 05:52 PM
Ok, i am statisfied with my shader so far. This is a poly with an aproximation node.
http://sor.typepad.com/.a/6a00d8350600cb53ef0120a7371e8a970b-pi
Now what is the technique to create an ocean that extends to "infinity".
i know that the create maya option creates a nurbz patch attached to the camera but i cant use it because i need a normal prespective effect where things look smaller when they are far from the camera. Is there a technique that uses adaptive tessellation where the surface near the camera has the highest triangle count?or any other technique that lets me render the whole ocean without running out of memory?

scene (http://sor.typepad.com/files/whole-ocean.mb)

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