As @gandalf3 pointed out, you can check out the answer here. I'll redo it with a bit more detail though.
I'll assume you've already UV mapped your plane (select plane, go into Edit Mode, U > Unwrap) and you already set up the texture in the Materials tab to look like this:
So, you render and the alpha appears as black.
To fix this, you go into the ...
Go to Light Paths under the Render Tab and turn up the Max amount of transparent bounces until you have enough for every cube.
For 2.8* set the Transmission bounces in the Render section>Light Paths>Max Bounces
You can make an object be displayed as a wireframe by setting the Maximum draw type to wire in Properties editor > Object > Display:
You make an object display as transparent by adjusting the alpha of it's material, and enabling Transparent in the display settings:
On the shadow catcher object, add a material and enable Shadows only in Material > Shadow:
This will make it so that only the shadows cast on the object are shown, the rest of the surface will be invisible, showing the sky behind it.
If you set the alpha to Transparent in Render settings > Shading, the sky will be rendered as image transparency.
You can use a Holdout shader:
The holdout shader will render as actual image alpha, as opposed to giving the color of the environment on the other side of the object.
Or you could use a Transparent shader, which will allow other objects to be visible through the transparent object:
Note that transparent in Render settings > Film must be enabled, otherwise ...
If you're using OSX you can use its Quicktime support:
Selecting any of the video formats in the Output panel.
In the Encoding panel change the format to Quicktime and select a codec that supports alpha (such as HuffYUV).
There are a couple things going on here:
The glass is not entirely white, so a noticeable amount of light is being absorbed. Setting it to white (or almost white) gives a more glassy result:
With a less uniform lighting/environment the glass is more visible:
In this render I adjusted the model to get rid of the subsurf artifacts and thicken the bottom a ...
You did have Transparent Shadows disabled in the Material Settings. Once enabled, you can use the Light Path Node's Is Shadow Ray to Select between the Glass and Transparency shaders to achieve this effect.
On Material Tab, go to Transparency Section, activate leaves' Material transparency, set it's transparency mode to "Z Transparency" and then set the Alpha value to 0.
On Texture Tab, go to Influence Section, tick Alpha and set it's value to 1. Don't forget to tick Use Alpha on Image Section.
If you use an opaque image with transparency mask image, you can ...
PNG images can't represent objects that emit light but not block any light, due to the way they represent transparency. For that reason, you must always have some amount of volume absorption for the emission to be visible when saved as a PNG image.
If your volume has zero density, you could use the flame to drive the volume absorption density, adding just ...
The paint modes named Add Alpha and Erase Alpha may be what you are looking for.
If you are using a pen tablet then you can use the pen eraser to use Erase Alpha without having to change the blend mode in the UI. There does not yet seem to be an alt key press that allows the pen eraser to toggle between Erase and Add.
Personally, I think the better way, ...
By default, some options that require extra computing efforts are turned off in Eevee and they must be turned on manually.
In the case of a refractive object, you must enable:
Under the Render settings, Screen Space Reflections and, within it, Refraction. manual.
Then, in each of your refractive materials' Material settings, you should enable Screen Space ...
All you need to do is use a Gradient Texture (see how to create it procedurally here: How to create a gradient texture?) as a mask for the transition between two materials.
Set up the nodes as pictured below. Try to experiment with a Mapping Node settings (adjust the Location, Rotation and Scale parameters) to achieve a desired effect.
To have a better ...
There is another way - using a similar technique to the procedural hex shader defined here to displace additional Image Textures to "fill in" the faked depth.
The following nodes will generate the required offset based on the surface Normal, the Incoming ray, and the 'depth' behind the image plane :
The output vector can be used as an offset to the Image ...
Use a Mix shader as the last node before the Material Output. feeding it the hair material (diffuse shader or whatever) in the lower input, a Transparency shader in the upper, and the image texture's alpha into the Mix's "fac" input.
By mixing a glass or glossy shader with a transparent shader based on a fresnel node, rays will be allowed straight through the glass at smaller angles of incidence, and will reflect at grazing angles. Rays which go through and reach the environment background will give alpha transparency:
Note that the Fresnel node is not necessary for mixing (setting the ...
A simple solution is to extrude the image plane (or add a Solidify modifier) and use volumetrics to add the depth by driving the Density using the image Alpha channel.
Use the following material :
Here the image Alpha is used to mix between Diffuse and a Transparent shaders to produce the Surface. In addition, the Image is also used to control the density ...
Geometry should not be an issue here, glass shaders are noisy by nature and will probably have a bigger impact in your scene. If you use this technique and take advantage of instancing feature the memory consumption benefits should help mitigate the number of objects.
Make a simple box mesh with the desired dimensions of your brick, make sure you apply the ...
It's a viewer issue only. Try compositing over a gray background using the alpha-over node.
If the result is correct, then your file output (without the gray background, of course) will be correct as long as you store it as EXR or any other format with associated (premultiplied) alpha channel, as it's the only way to store pixels that are both transparent ...
This Answer is incomplete, but might bring you closer to your goal.
I used a Volume shader hooked up to a voronoi texture to create the bubbles, but I didn't manage to make them glossy or refractive.
Is that even possible, using volumes?
The biggest problems with your render are:
it is only one closed volume, it will never give realistic results
The setup is very basic. One thing to note is that I've used Wireframe modifier with second material.
Just a mix between Transparent and Emission which is added for colorization and "nicer" visibility.
First slot is above material for transparent object, second is for wireframe.
Most important thing here is to set Blend ...
In CYCLES select the mesh you want to be transparent. Go to the Object header and check the Transparency box.
Go to the Material header, add a new material and decrease the Alpha value in the Settings panel as pictured below.
You may also change the color of transparency.
In BLENDER INTERNAL do the same things in Object header as shown above. Next go to ...
You misread the answer, and my suggestion wasn't terribly clear. Any imager should be "pro" associated (aka crap term "premultiplied") alpha.
There is a good reason, and I will expand this answer when I find some time later.
The bottom line is that only associated alpha models a real-world correlation, where unassociated doesn't.