Visibity problems

[cybling]

Hey,

Im currently making a film at the moment. Im coming close to the rendering stage now but ive come into a potentially big problem while doing some tests. Some of my characters are semi-transparent and fade in from nothing and stay at around 80% visibilty. The way im achieving this is to right click the object and animate the visibility wheel. Vray can handle this, however the render time goes up around 15x. A frame will normally take around 1.4mins and now im getting render times for 1 frame at 16mins. This is really not acceptable for render times. i was wondering if there is another way i could achieve the effect of the character gradually fading in from nothing and staying at aroud 80% opaqueness.

I was thinking that i could do a separate pass of the character on its own and achieve this in post, but i want the shadows (and GI) of the character to also effect the surrounding character and scene...but not sure how to do this :S Hope someone can help!

[Morbid Angel]

Post is way to go in your case, here is a great tutorial on how to achieve pases with vray (gi and the rest)
http://www.kaadesigngroup.com/temp/compositing_tut.html

[cybling]

Cool, thanks for the link. I might have to come back to this thread when it comes closer to the time when im gonna composite it all.

Btw, is the way vray takes so long to render visibility a bug or is it a normal thing you'd expect?

[percydaman]

its a raytracer from beginning to end, not a scanline renderer like max, so anything thats see through has rays shot throught it.

[cybling]

Ah ok i understand Thanks for that, ill get stuck into the ol' compositing then so!

[cpnichols]

Post is way to go in your case, here is a great tutorial on how to achieve pases with vray (gi and the rest)
http://www.kaadesigngroup.com/temp/compositing_tut.html

Vray's Gbuffer is pretty powerful right now, and can output many of these passes all at once. It will save you from having to render seveal renders.

Just to note.

[Dynedain]

That was a quick tutorial written by me, based off of notes and questions I asked morbid. I don't guarantee its accuracy, or that its the best way to do things. It was meant mostly so that I could understand the kinds of process involved, and use as a sortof checklist.

[Morbid Angel]

cpnichols I agree but during my times when vray wasnt as advanced with gbuffer i had to learn this way, and with it i live now...maybe in a future i will adopt with gbuffer however, for instance speculars in gbuffer are only supported for vray mat and often i use standart speculas so, for things like that.

[cybling]

Cheers for the help, much appreciated Yeah ill be using Gbuffer for the shadow pass and the GI pass. Here's a viewport shot of the scene..the hands on the left (woman's hands) clasps the hand on the right (man's hand) The woman hands and body on the left here will gradually fade in and stay at around 80% opacity. Im still sort of confused as to what layers i need. Would this be about right?..

1. A pass of the everything in the scene except the woman (no shadows or gi?).

2. A pass of just the woman. (although, if i just do this, then how do i make sure that her legs are under the piano? Will i have to render the piano off as a seperate layer too to put over her??)

3. Shadow Pass (Confused how to get this tho, since i need the shadows that will be cast from the woman's hand onto the piano and man's hand. Do i just uncheck 'visible to camera'?)

4. GI pass..since the woman's hand will be in contact with the man's hand (Again, same as shadow pass, im not quite sure how to do this)

Am i on the right track at least? Sorry im asking all the questions, i suppose its a big learning process for me..not used to comping stuff :S Can anyone give a helping hand?

[/img]