Hi
We were given some “recording and post-production” task but since I don’t have any camera with a decent resolution to record it I decided to do mine in 3ds max.
I will make some simple scene with: a camera moving along a path, one character moving from left to right and a row of mirrors behind him. What I want him to do is to gradually fade but his reflection should remain unchanged. And this is the problem I cannot solve. How to do this? I was thinking about animating his material opacity but that would make the reflection also fading. Any hints?
Soft:max 2012

It’s the sort of thing I would probably do post render in a compositor. Render the scene normaly, then again with the character not visible to camera, but visible to reflection. Then it’s just a case of fading one render to the other.

Thanks. I will give this a try tho I’m completely new to Composite.

It’s a fairly simple compositing task. For tips on using Composite see Ken LaRue’s blog.

Thanks for the link, I will definitely have to watch it. :<
I also thought that it would be easy to achieve but so far I’m stuck in a certain point.
I have prepared 3 sequences:
A: the object invisible to camera, just the reflection(non-fading, 100% opaque throughout the whole animation)
B: the object fading in the camera(animated opacity) and invisible to refractions/reflections i.e. invisible in the mirror
C: (probably useless)- the object fading both to the camera and in the mirror.

In the Composite I used the “Blend & Comp” tool which allows to put sequences in: Front, Back, Matte(no idea what it does) and Mask. I put A and B sequences in multiple combinations with all possible Blend and Comp modes without much success. The only “satisfactory” result was obtained when I set the Blend mode to Darken. However, it was rather cheating than getting the real effect as in the beginning the object was already hollow a bit, instead of being 100% opaque.
I know what I need to get: the mirror reflection in the back blended with the front fading object without the are of mirror being influenced by the non-reflected sequence. I need to exclude some particular area-the mirror from being overwritten by the second one. And I have no idea whether I should use a mask for it.
I’m gonna take a look at these tutorials tomorrow, maybe I will find some solution.

What I would do is render:-
A: The object visible to everything, camera and reflection as normal, no animating of any visibility.
B: The scene with the object invisible to camera, but visible to reflection, again no animation of the opacity.
The idea is you do the opacity animation in Composite by animating the Blend from sequence A to B.

yeah...now I know where my assumptions failed :D I will try to animate the opacity in Composite however, your post and an almost sleepless night made me rethink all that stuff and I finally figured out how to to do it in Max alone. I realized that I need two characters- same positions, steps etc. The first invisible to reflections, with animated opacity and the second with solid material invisible to camera but visible to reflections. <insert_Dr_Evil’s_face> :D
The reason why I tried to avoid Composite is that I simply had no time to watch any of its tutorials, like you know-being given a task in max without any tuts...The way I’ve done it in Max is possibly cheating a bit but saved me a lot of time and memory(geez, now I know why you guys have 24+GBs of RAM...)