Any work done on fading an object in and out?

Any work done on fading an object in and out ? I got ONE object to work as intended, but when I applied THE VERY SAME SETTINGS at THE VERY SAME KEYFRAMES to another nearby object, the 2nd object didn’t work as intended. The first one did, but the 2nd one never did. I TRIED removing keyframes so I could start over, but even tho I “REMOVEd KEYFRAMES”, the problems didn’t drop off so I could start over. No keyframes, but errant operations remained.

I TRIED animating the VISIBILITY of LAYERS but LAYERS still seem to POP-IN and POP-OUT, with NO FADE, unusable.

This from 2017:



Mar '17

I need to fade an object in and out. Its EASY to do in BO-1, but changes don’t stick to keyframe markers in BO-2.

Tried both ways -

  1. Edit the TRANSPARENCY setting in the Keyframe from 0 - 100 - 0. Changes do not stick to keyframes.
  2. Edit the TRANSPARENCY setting of the part in the MATERIALS EDITOR from 0 - 100 - 0. Changes don’t stick to keyframes.

Any suggestion would be welcome.

Thanks -



Has ANYONE done ANYTHING to package the ability to FADE-IN and FADE OUT as desired ? I can’t imagine I’m the ONLY RH/BO user who has this need, so ANY help would be GREATLY appreciated -

Thanks !

C. Fee.


Transparency does ‘stick to keyframes’.
Only… one has to press and hold the timeline-slider-arrows to get a decant preview.



Hi !

Yeah, I’m aware of this step and was REALLY EXCITED (!!) until I tried it.

There I discovered that highlights and other things like Gloss , Refelectiveness and IOR for transparency were left untouched. and left behind a “Halo” of reflections, shines and visual bends of objects behind the now 100% “transparent” object, that left the result unusable. You may remember, as you were a big help back when we first visited this subject.

I’m thinking YOU are probably the BEST person to have replied, so THANKS !
Its good to hear from you, I hope this finds you and yours doing well !

So, tho -
to my original question:
Has ANYONE done ANYTHING to package the ability to FADE-IN and FADE OUT as desired ?

Thanks again -

Charles S. Fee
Sr. Mechanical/Structural -
Machinery, Industrial and Commercial Product Designer (40 Year)

3D/2D CAD Designer, Modeler and Animator
NEW Product Development
Patent Support a Specialty !

We have been rendering two animation tracks: one with all the objects full opacity, one with the object you want to fade-out completely hidden. Then we blend the opacity of the two video tracks in Adobe AfterEffects. Of course this doubles your render time and adds extra post-processing work. You can also use Camtasia to do this (cheaper software) and probably even some free options out there.

It would be nice if Bongo have a way to animate object opacity/visibility, instead of just transparency.



Thanks for the compliment.

To be honest, I only vaguely remember a ‘halo’ issue (I’m getting old), but I cannot track it down.

I don’t understand exactly what you mean. For “Highlights” (as far as I remember) we have to go back to Rhino 2 or 3, but long gone since anyway. As for Gloss, Reflectivity and IOR: they are by default set to 0%, 0% and 1 and they remain that way as long as the data isn’t changed in a keyframe. So they cannot influence the rendered image nor give a ‘halo’. Can you post an image and/or a model showing the phenomena?

Concerning Opacity: I feel that opacity is a feature in image processing, not so much the property of an object. So I think your questions (to make an object only partly visible in a render, including its effect on other objects and environment ) is a matter for the Render department.
Then later on Bongo can (hopefully) make it animate-able.

Best regards,

Hi -

It looks like we have this on the list as BO-2792.


Thanks, bud !
I’m GLAD you folks found a way to meet this FUNDAMENTAL need.
Sorry, tho- your work-flow is NOT an appropriate solution we can apply to something that SHOULD be simple and internal to current Bongo.

This was BASIC in R-4/BO-1, but with the IMPROVED RH-5/BO-2, we LOSE this very fundamental function.
I’ve tried SO MANY things to TRY and get SOMETHING usable, with no workable success.
I DO use Camtasia with STUNNING SUCCESS, but no, the workflow path you suggest is certainly unworkable.

Good luck with it tho, as it seems to meet YOUR needs.

Thanks for trying, bud -

All the BEST to you and yours -



Come on, bud.
As long as they don’t get changed by a keyframe ? SERIOUSLY ?
They get SET to values, in order to configure the material to give the appearance desired.
They ARE NOT then adjusted at a keyframe.
Opacity (Transparency) IS adjustable via keyframe editing, LEAVING BEHIND THE HALO EFFECT I describe. This CAN NOT be difficult to understand.

Transparency ? Seems an AFTER-THOUGHT, as -
In RH-4/BO-1 it was a simple VISIBLE/NOT VISIBLE setting, fading over the Keyframed range. Maybe …

Ok, hope this makes it clearer.

Thanks -



As far as I know visibility has always been an on/off object property, also in Rhino 4.
But I think I understand your problem. Indeed Visibility <> Transparency. Other material attributes like Gloss and Reflectivity (can) indeed create a kind of ‘halo’.
100% Transparency, 100% Gloss, 100% and Reflectivity

To make an object gradually ‘invisible’ they all have to be animated, which is laborious.

What ‘we’ need is a gradual visibility (100%…0%) in Rhino. When Rhino would provide such this would not only be a nice feature in rendering stills, but a great opportunity for Bongo users to animate an objects visibility without having to tamper with various and multiple material settings.


hi @Luc,

I wonder if the work on layer transparency that @stevebaer is doing has potential to create the right pipes in the software to eventually control also visibility at at object/layer level, instead of editing materials’ physical properties. link here: Rhino 7 Feature: Transparency


Hi Gustavo - I’m not sure what you put behind “potential” here but basically those two features are completely separate issues.

Hi Wim, I was seeing the layer transparency work as a way to control visibility opacity of object, not just the transparency of a material assigned to an object. But maybe I got that wrong.

Don’t worry, Gustavo. I also got that wrong the first time and was firmly set in place :sunglasses:
Also, note that you just wrote “transparency of a material assigned to an object”. The transparency feature that was just introduced is only about layer/object color; it doesn’t have anything to do with the transparency of materials (which has been available for a long time).

Gentlemen, the issue is not transparency, the issue is visibility :face_with_raised_eyebrow:
A glass is transparent but not invisible.

I feel there are 2 options:

  • create fading ‘visibility’ as a property of an object giving its effect in any display mode and in rendered images regardless the render engine used.
  • create fading ‘visibility’ as a property of a material, hence making an object more or less invisible in rendered images.

Beats me which one is feasible.

We can control visibility of Rhino objects with the existing Content (a.k.a. Render Content) keyframes. These keyframes have magenta color (because I believe that magenta is the best color for these keyframes). The Content keyframes control both transparency and refractive index. The refractive index = IOR = index of refraction (in Rhino speak). The vacuum is invisible because it has the refractive index of 1 and 100% transparency.

Probably the best way to fade an object is to gradually change its transparency and its refractive index at the same time. If the original refractive index equals 1, there is no need to change it.

So , as far as BO-2 is concerned , the answer is both NO and NOT EXPECTED because , well … .
Ok , no worries .