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sidewing
08-22-2004, 02:06 PM
What I have:
A yacht and water.

What I want:
Render out only the yacht (for compositing purposes). However, I still want to have the water raytraced on my yacht. Also, I want to have the alpha channel from the yacht (black).

Question: How can I get only the yacht rendered with the water deducted from my yacht alpha channel?

Thanks!

John



www.trade-show-animation.com

Triple G
08-22-2004, 02:51 PM
Go into your render options for the object, and make the water Unseen by Camera but SEEN by Rays.

sidewing
08-22-2004, 04:13 PM
Thanks for your reply.

That doesn't work... As soon as you make an object "unseen by camera", it will indeed calculate raytracing but not alpha channels.

Other suggestions?

John

Trevor
08-22-2004, 05:03 PM
Set the alpha channel in your surface editor/advaned panel to constant value 0, for your ocean surface.

Triple G
08-22-2004, 05:06 PM
Ahhh....I misunderstood what you were trying to do. Trevor's suggestion should work. :)

sidewing
08-22-2004, 05:28 PM
Thanks Tripple G and Trevor!

I understand how I can deduct the alpha channel of the water from the yacht. However, the water will render in that case (higher render time)... I only want to render the yacht.

Sorry for not being clear...

Triple G
08-22-2004, 06:07 PM
Well, you could turn the water into a matte object (black). Technically, it would still be rendering, but it'll almost certainly be a lot quicker than a full-on render with all your surfacing applied. I think you'll still need to set your alpha value to 0 for the water surface(s). This should work for you. :)

sidewing
08-22-2004, 11:27 PM
Great idea Tripple G!

I thank you.

The render time is now indeed sub-marginal.

Great thinking.

sidewing
08-22-2004, 11:28 PM
Speaking of which... Do you have any experience with rendering out in PSD exporter plugin and use color id and and Z-depth?

Triple G
08-23-2004, 09:52 AM
Glad that worked out for you.

I tend to not use the PSD exporter much, since the layers it produces are stacked in the wrong order, with improper transfer modes. Also, since I use After Effects for most of my compositing work, the fact that AE doesn't support layered PSD sequences makes this kind of useless for me.

I do use the extended RLA/RPF exporters every now and then. They work well for some things, not so well for others...it's just a matter of playing with them and seeing what they can do for you.