No Ocean Wake In Render

[petko]

I created an ocean wake which is visible in preview render (maya software high resolution render). After batch rendering there is no wake displacement in the rendered sequence.
What is the problem?

[duncanbrinsmead]

Try caching the fluid simulation first, especially if rendering on a renderfarm.

Duncan

[petko]

Thanks for your help. BTW where can I buy your DVD?

I followed your advice in one of your posts (making the ship as the emitter).
There is foam on the wake but the surface displacement is absent. Also, I noticed as the camera goes wider, there is a grid like pattern on the ocean shader. How can you fix this?

[duncanbrinsmead]

There are two fluid textures: one for the wake(displacement) and one for the foam. You need to cache both. To keep the ocean from looking too regular when viewed from high up you need some very low frequency waves in the mix. Increase numFrequencies and wavelengthMax. You may also need to lower the waveHeight attribute a bit to compensate.

Duncan

[petko]

Thanks a lot!

[petko]

I cached all fluid textures. I still don't see any wake displacement.
I used suface emitter type for both wakes. Should I use volume for the wake displacement?
Also, for the fluid texture type I used perlin noise for both.

I followed your advice on the making low frequency waves. The ocean grid like texture is eliminated.
The foam texture on the wake is fine but there is foam all over the ocean texture even at the distant part near the horizon. I rendered another sequence without the foam. i just mixed and blended both sequence using masks. I there a way to adjust the ocean shader to lessen the foam as the ocean shader gets farther from the camera?

[duncanbrinsmead]

I take it you see the wake on the preview plane in the interactive, but it doesn't show up in the batch render. I'm not sure why this would be the case, especially if it is cached. Does a simple wake on a default ocean render OK?

You can simply texturemap the foam emission attribute in such a way as to make the more distant foam less(perhaps a circular ramp texture). If you want to make it relative to camera distance you could project a circular ramp down y and parent the projection to the camera position. A yet fancier way would be to plug the pointCameraZ from a sampler info (represents distance, although may be negative) into a value remap node then the output of that into the foamEmission. You need to ajust the min/max input/output ranges of the samperInfo to get the desired foam range.

Duncan