Can I Stop Reflections in Glass Material

Trying to render a small scene in V7, its for presentation purposes. I have an object inside a light bulb, in rendered display mode it looks as intended, if I switch to Raytraced or use the Render engine window I’m getting the reflections of the sofa bouncing off the glass bulb ? Im wanting to export a rendered image out with a transparent background, screenshot attached and file too, @nathanletwory @theoutside maybe you guys have some tips ? tia :+1:
sofa in bulb V7.3dm (9.9 MB)

1 Like

Hi @milezee

If you don’t want reflexions on the glass just give your glass material an IOR value of 1
Screenshot 2020-07-09 at 01.53.33

Is this what you are looking for?

Also bear in mind that you have activated Use custom environment for reflexion hence it’ll cause reflexions on a normal glass.

1 Like

It looks to me like these are refraction in the solid piece of glass - I would keep reflections/environment on, and either give the glass some wall thickness or use ior = 1


1 Like

The Raytraced version looks weird because your glass is just a single surface. As it stands it acts more like a solid glass bulb instead of a light bulb. This gives the very high distortion factor. To fix that give your bulb thickness. IOR 1.0 will just look unnatural.

Anything glass should always have some thickness, unless you really want a glass sphere or bulb. But especially window panes you need to give thickness. Fortunately there is the thickening modifier that you can use.

Word of warning: if your intent is to get also transparency through the light-bulb then this is currently not possible with just Rhino. We don’t have the proper tools to do that (render layers, compositing, light path control). You can get almost useful transparency through glass by ensuring the ground plane is behind the entire object.

1 Like

Why is that Nathan? This is the first time I hear that you have to give thickness to a windows pane. Doesn’t this will increase render time because of the refraction produced by those thick panes? In real live you don’t appreciate refraction produced by windows and usually having reflection Is good enough.

Maybe deactivating cast shadows on the bulb could help to get that white background?

Do you plan to add those to raytrace in the foreseeable future? Also, adding something like hide from camera, hide for reflection/refraction would be very handy for cases like this one.


1 Like

@nathanletwory @jespizua @pascal thanks for the input guys, I will have a play around and test :+1:

1 Like

With an actual glass pane light gets first bent on entering the glass, then bent again on exiting on the other side. When using just a single surface a light ray gets bent only once, giving a completely wrong result.

To exaggerate here a trimmed sphere. The one on the left is kept as single surface. The one on the right has been given a bit of thickness. You see that the sphere on the left warps the light rays quite a bit. The same happens for straight, single-surface window panes. It will lead to unexpected results.

With the window pane added to illustrate the weird result when left single-surface

Setting IOR to 0 is no good either, since that essentially turns off fresnel as well, making this glass pretty useless. In such case just leave out the object…

I was talking about transparency as in alpha transparency in the final image, where you’d have the glass participate in the alpha channel of the image so you can replace any background.

Probably not for v7, no. In the future most likely yes.


This is very beautiful, I wish I could use photoshop.

1 Like

Yes I have done something similar in Affinity Photo before (basically the same as Photoshop). I wanted to try in 3d modelling space a similar look to add to a presentation of ideas :+1:

Understood. This is not what I’m used to from other render engines, so thank you for explaining that.

Yes, me too. That’s why I referred about the shadow that gets inside the bulb, it’ll cause an effect if placed on top of another image in post.

I love how every question in the forums turns into a teaching class and we always learn something new.



Right, these engines typically have a thin-glass material, that does this simulation for you. We don’t have such a material (yet? who knows), so you have to do this manually.

For that just set the groundplane much lower than the lowest point of the bulb. Except the groundplane panel seems to not work currently as it should. As a workaround you can add a tiny tiny sphere way down and outside of camera view.

Yes exactly that. Is it possible to add coating layers on top of a base layer in Blender Cycles? or Cycles doesn’t work like that. Something like creating the base layer with IOR =1 and then adding a coating layer on top to give reflection to that material.

Nice trick!!


Sure. You can make very complex materials for Cycles, but we don’t have direct support for that in Rhino yet. In The Future we want to make it possible to create custom.shader graphs.

1 Like

Great! So it’s just a matter of time to have it implemented in Rhino :wink: