9
votes
Accepted
Does premultiplied alpha give order independent transparency?
Premultiplied alpha itself does not give you order independent transparency, no.
This page talks about how it can be used as part of an order independent transparency solution however: http://casual-...
- 7,811
7
votes
Accepted
How does the Painter's Algorithm handle transparency?
The common way to render transparent polygons in a rasterizer is by use of Alpha Blending, which basically combines the colour of the supposedly transparent pixel with the colour of the background at ...
- 1,620
7
votes
Blur with alpha transparency
Two suggestions:
If your data is from an image you are displaying on a standard monitor, the chances are it is (or you are implicitly assuming that it's) in sRGB format. This means that the colour ...
- 4,336
6
votes
What causes blobby edges with alpha testing?
Let's consider the simplest case, where our texture is 2x2, with alpha values $a_{0,0}, a_{1,0}, a_{0,1}, a_{1,1}$. With bilinear filtering, the alpha at $uv$ coordinate $(x,y)$ is
lerp(lerp($a_{0,0}$,...
- 251
5
votes
Accepted
Why is this not a proper solution to handling transparency in deferred rendering?
PaulHK is right in what he said: you have to consider that there may be more than 2 transparent objects behind each other.
Also, the idea of deferred shading is to render the geometry only once to be ...
- 1,613
5
votes
Does premultiplied alpha give order independent transparency?
From the proof of premultiplied alpha blending, there is an assumption that "the operator must respect the associative rule."
So, it may lead to confusion of the order of process.
Since this is not ...
- 51
4
votes
Does premultiplied alpha give order independent transparency?
Alan, Jim Blinn's compositing article also explains why premultiplied is the correct way to do any filtering of transparent images.
- 4,336
4
votes
Accepted
Are there tricks for getting proper sort ordering on particle systems?
First option should be to make all particles able to go through the same pipeline. Perhaps with an uber shader. That way you can batch them all.
Positive ieee floating point numbers can be sorted ...
- 6,020
4
votes
Accepted
How does ray tracing handle the calculation of reflections and shadows in the presence of multiple translucent objects?
First off, I think the question is a bit vague. I'm not exactly sure what you really want so this answer is just based on my understanding of your question.
Raytracing handles reflections and shadows ...
- 1,302
3
votes
Accepted
Hard Shadows with Dielectrics/Transparency
"Refracting the shadow ray" is really the wrong mental model to use to think about this. After all, shadow rays are not real things; light rays are. Shadow rays are only used to test for ...
- 25.3k
3
votes
Accepted
Benefits of Clustered Shading vs Tiled Shading?
Both Unity's "Deferred shading rendering path" and "Legacy Deferred Lighting Rendering Path" work only for opaque surfaces. They both rely on a very similar set of passes:
Render the opaque objects' ...
- 830
3
votes
How does the Painter's Algorithm handle transparency?
I would like to add that Painters' algorithm can be run from front to back with transparency provided your blending operations are associative. I would recommend reading Jim Blinn's "Compositing, Part ...
- 4,336
3
votes
Accepted
using default depth buffer in off-screen framebuffer
Is it possible to bind default framebuffer's depth buffer to another framebuffer?
First, you "attach" images to framebuffers. You "bind" objects to the context; you "attach" objects to other objects.
...
- 9,997
3
votes
Accepted
Avoid having an opaque and transparent variant of each pixel shader
You can use a threshold set through a constant buffer to clip pixels (ie an alpha test):
...
- 25.3k
3
votes
Additive blending with weighted-blended order independent transparency
I have worked with this specific formula for the OVER operator but not with additive blending. I'll use the paper's nomenclature in the following discussion:
$$ C_f = \frac{\sum_{i=1}^{n}C_i \cdot w(...
- 830
2
votes
Equivalent of Fresnel law for determining transmitted/diffuse split
Physically, the origin of diffuse light is subsurface scattering, which happens continuously as light travels through a material. So, the proportion of transmitted light depends on the thickness of ...
- 25.3k
2
votes
Is it possible to override or disable blending per pixel
You seem to be using additive blending against its purpose. Additive blending is supposed to represent light from multiple sources being combined. It is not physically possible for one source of light ...
- 9,997
1
vote
Accepted
How is HTML Alpha-Blending Different than GIMP?
I've discovered that GIMP (as of v2.10) has a new set of "default" blending modes which is what I used for creating my images. If, using the two images, I blend them using "legacy ...
- 121
1
vote
Create a transparent PNG
Like the color values, transparency is a piece of information that needs to be stored in an image. A quite common data representation is RGB with the channels red, ...
- 1,261
1
vote
OpenGL transparency - object behind is not rendered
It depends on the order of rendering. When first rendering the object which is far away and then rendering the closer object, the transparency will work. Otherwise when first rendering the close ...
- 1,366
1
vote
How to draw depth-based volume in real-time
The issue is that an extra depth pass won't cut it. You may need an arbitrary number of extra depth passes. Just imagine the volume between two sinusoidal surfaces, you would have infinitely many ...
- 2,561
1
vote
Why is this not a proper solution to handling transparency in deferred rendering?
A fundamental assumption of deferred shading is that there will be only one surface, and therefore only one depth, at a given pixel.
An effect that contradicts that assumption will require some sort ...
- 4,440
1
vote
Are there tricks for getting proper sort ordering on particle systems?
Sort the particles by Z each rendering cycle using an algorithm such as bubble sort which is good when element changes position in small steps. If the perspective does not change much the errors would ...
- 359
1
vote
Alpha blending between two overlapping semi-transparent shapes
I used Stencil Buffer to fixing your problem , you need a way for checking overlapping two or more shapes
...
1
vote
Volumetric raycasting with transparent rasterized geometry
This is called "deep shadow mapping" and deep compositing.
Sadly invented long before you had this ideas yourself);
Now you are talking about implementing this idea specifically on a given ...
- 656
Only top scored, non community-wiki answers of a minimum length are eligible