Glass product shot with pure white or transparent background

Support Lighting and Rendering
#1

Hello!

I am trying to do a simple product shot of a glass. I want the background to be pure white. I have tried both setting the world to white and increasing the strength and setting the world to transparent. I really am not able to get a white background, and I have some weird problems when using transparency. Half the render turns out white, the shadow catcher is transparent, the glass is white. I would really like the glass to look like glass with the non-reflective parts transparent, and I would like the whole background to be transparent as well. This way I can add the white background in the compositor and have more freedom.

Can someone help? Blender-file attached.

Attachments

help.jpg1920×1920 93.8 KB

red wine 6.blend (1.47 MB)

#2

All shaders in Cycles that have a refractive component will render opaque. So, if you want the non-reflective parts to be transparent, you will have to use a non-refractive material = some kind of transparent/glossy mix. Don’t expect that to look even remotely realistic, though, as refraction is pretty much the defining trait for glassware.

Your ground plane is set to only be invisible in the viewport, that’s why it shows up in the render. This is your file with the ground plane disabled for the render as well and a simple glossy/transparent mix material with Fresnel as mixing factor.

Auswahl_002.png677×792 64.9 KB

The area where the handle connects to the upper part looks completely fake without refraction…

Anyway, I have doubts about shooting a glass in white light before a white background. Not sure that will ever make a nice image, as it’s almost impossible to get any contrast between the glass and the background. I’d rather render that before a black background, no? Or at least in a dark environment?

#3

Well, that explains the white plane problem! I actually did not know I had that plane in my scene, I thought I deleted it but I just hid it. Thanks for pointing that out!

As for the product shot render, what would be the best way to solve this realistically? That is, having a background that is as white as possible without washing out the entire shape of the glass? It does not need to be perfect because I can fix a smooth transition to pure white on the edges of the image in post so that it fits well on pure white backgrounds without having to be transparent at all.

It would be nice to avoid any gray areas that I seem to get using a bent plane for example.

#4

You can use a different environment just for the camera. Let the camera see plain white, while the rest is lit by some nice dark studio HDR, for example. If you then switch back to a refractive glass material, you can use that rendering opaque to your advantage. Here’s a quick and dirty experiment:

Auswahl_003.png678×779 73.5 KB

Node setup for the environment:

Auswahl_004.png1061×595 79.8 KB

The glass refracts the darker environment, but the camera only shows white all around.

#5

Thank you for the fast and amazingly good answer, I will experiment with this and I am sure I will get a good render. Your example is exactly what I am looking for!

#6

Result, for those interested :slight_smile:

Thank you so much!

render_cropped.jpg2300×2300 51 KB

#7

I just came to realize that you asked for a “realistic” way to do that, as in “What would a photographer do?”…
When it comes to glass, you will often see two very different looking methods to set up the shot, which are both very similar in their basic layout: Bright-field lighting and dark-field lighting.

Bright_Field.jpg1000×1000 80.6 KB

Dark_Field.jpg1000×1000 119 KB

In bright-field lighting (top render) you basically have a dark room, with an emissive object just behind the glass objects, ever so closely filling the camera view. That way the glass will reflect the dark surroundings on its edges, giving a sharp contrast to the bright background.

In dark-field lighting (bottom render) you use a very large diffuse light source in the back (e.g. an illuminated wall), with a small dark card hiding that from the camera’s field of view. This will do the opposite thing: a white outline of the glass against the black background.

#8

This is top notch, high quality info right here!

You sir/ma’am, have taken this to the next level! This is EXACTLY what I am looking for and wanting to reproduce. I will experiment with this as soon as I have an opening in my schedule!

Just incredible.

#9

Also observe, in both the light-field and dark-field setups, that you do not see through the glass at all. There is, instead, a very conscious effort to exhibit only the surface characteristics. And, the characteristics are not the same: a light-field shot highlights the apparent opacity of the glass where the light is passing through a thick segment of glass and most of the light is thus being refracted away from the camera lens. Dark-field uses an entirely different lighting set-up which showcases the orientation of the glass to a strong, directional but entirely-featureless light source.

Incidentally, this effect can be very-effectively “faked” (and, without Cycles) through the use of a node-based texture which considers the angle-of-incidence and maps this using a “Curves” node. I’ve even seen this done without​ any actual light-source on the set: the object emits​ the light.

#10

Wow, very interesting!

Do you perhaps have a link to someone showcasing this at all?

#11

Observing, searching… skills long forgotten, ey!!! :wink:

#12

By no means! I actually just searched and watched that video. I was thinking more about the specifics of the faking of the effect using nodes and curves that was pointed out.

#13

ah… apology

ok then
think of reflection as an emission from the surface dependent on the POV :wink:

#14

No problem at all!

I think I am just way too new to 3D-rendering to start to grasp such a concept without very simple explanations. But I hope and think I understood the bright field and dark field concepts! Below is a render where I attempt the bright field technique. I think it came out pretty well compared to my first few renders!

Any tips on improvement or obvious mistakes are welcome. Also: I get sort of an aliasing effect on the bottom rim of the glass when only showing the camera a white background as was explained to me above. I had the strength at 1000, but dragged it down to 100 and it got better. Are there any other ways to avoid this and still getting a crisp render? I don’t want to reduce the strength to a point where the background starts to go below pure white.

Well, it’s barely noticeable at 100 as seen below, but anyways, nice to know!

rendertest5.jpg1650×1650 96 KB