Fade Geometry function - Any suggestions? (VRAY for Maya)

[Tyrellcorp]

Hi all.
I'm trying to find a way of doing a linear fade to a block of geometry within a scene. I have looked at the VRaySphereFade function but it essentially applies a fade gradient which travels from the centre of the volume to the edges. You'll see from these screen shots what I am trying to achieve. Stills 1 and 2 show the volume where I need the linear fade to apply and in Still 3 I have mocked up the effect I am after (in Photoshop). I have contacted Chaos Group about whether a modification of the VRaySphereFade function is possible and they have indicated this feature could be introduced if enough users deem it useful. The fade feature could be modified to use a cuboid volume with the ability to apply a linear fade in X, Y or Z. If this gradient could be adjustable that'd be brilliant. If anyone knows of an interim way of achieving this that'd be great. Many thanks.

[Morbid Angel]

Hi all.
I'm trying to find a way of doing a linear fade to a block of geometry within a scene. I have looked at the VRaySphereFade function but it essentially applies a fade gradient which travels from the centre of the volume to the edges. You'll see from these screen shots what I am trying to achieve. Stills 1 and 2 show the volume where I need the linear fade to apply and in Still 3 I have mocked up the effect I am after (in Photoshop). I have contacted Chaos Group about whether a modification of the VRaySphereFade function is possible and they have indicated this feature could be introduced if enough users deem it useful. The fade feature could be modified to use a cuboid volume with the ability to apply a linear fade in X, Y or Z. If this gradient could be adjustable that'd be brilliant. If anyone knows of an interim way of achieving this that'd be great. Many thanks.

not the same but what if you use a plane at the bottom of your object and a distance texture to opacity?

[stezza]

Would be a good addition, thumbs up from me.

[SonyBoy]

You don't specify whether this is for animation or print/still output (if it's the latter then simply painting is going to be the easiest way by far).

If for animation/moving camera, perhaps environment fog would achieve the same effect. You'd have to isolate the geo that you want to fade in post, but this ought to work.

[vlado]

The most reliable way to do this is in post - i.e. blend an image where the object is present, and an image where it is not.

Best regards,
Vlado

[Tyrellcorp]

Hi guys, thanks for your suggestions. It's for print and unfortunately each image will be 8000x6000 and I need to do multiples of each with the escalators/lifts and stairs in different locations. Doing a post process just isn't practical. I'll look at the volume fog but am not hopeful. Thanks.

[Tyrellcorp]

The object in question (escalator/stairs group) is made of multiple sub models and so applying a fade in the materials isn't really an option. Got a fairly muted response from Chaos about this issue which is a bit frustrating. I'm no coder but I can't help thinking a modification of the SphereFade or Clipper functions would be straightforward. If you could apply a simple ramp to a clipper volume I'd be laughing! C'mon ChaosGroup, please implement this!

[Tyrellcorp]

Hi guys,
I've tried the various suggestions but without any luck. To Chaos, have you any plans to maybe tweak SphereFade or Clipper to allow a more powerful object fade function? In particular the ability to assign a linear ramp to the fade in X, Y or Z. Thanks.

[smbell]

Can the stairs not be rendered as a separate element and have the bottom faded out in Photoshop or whatever? I know you mentioned earlier that it was not practical, but I'm not sure why? we do stuff like this all the time.

[Tyrellcorp]

Hi SMbell. It's just not really going to look correct as the projection of the 3D is looking downward as in picture 1. If it was like in picture 3 (my PShop mock-up) then yes your proposal would sort of work. I've also got stairs and escalators coming up from the floors that will need to be faded out at the top rather than the bottom. Very frustrating I can't find a way to do this. Arrghh!