Animating visibility on a transparent object

[Brian Jones]

Start with Transparency – 100%, Refraction – 1, no Specular – animate Specular Height, start at 0%
End with Transparency 90%, Refraction 2.4 and whatever Specular Height you were using

[Guy Carmeli]

Thanks Brian,

This method worked great, but has now created a new problem…. :-\
The object I am animating (in this case a diamond) is not appearing out of the blue, but rather from within another diamond (I’ve tried uploading a sample render, but for some reason it hasn’t been posted).
I’ll try to explain: a model of a diamond is floating in space, revolving around itself; at a certain point, several versions of the same diamond are “born out” of it, organizing themselves adjacent to it.
Initially, all the models are placed together at the same position, only being invisible. The problem I found – which seems to me like a bug – is that when you place two or more similar objects one on top of the other – even if the others are completely transparent and seem invisible – they drastically affect the visible object.
Do a simple test: create an object with a transparent and refractive material. Duplicate that object, keeping it in the exact same position. Create a separate material for it, making it completely transparent with a refraction of 1. Render once with the additional object, and once without, and you’ll see the difference (creating some background and lighting might help).

Thanks again,
Guy

[Brian Jones]

I see the problem. That’s the way it should work if it’s inside, I think. The light hits another object with a different refractive index and so the light bends…. The only way I can think of with the diamonds inside each other is to do it with Booles like this… and that’s assuming you only want to see them as they exit not while they are still inside.

[Guy Carmeli]

Thanks Brian – that’s a great solution!

I truly appreciate your effort.

Guy