8
votes
Accepted
Handling Projective Aliasing In Shadow Mapping
Shadow mapping with acceptable quality is quite a journey. So you implemented first step - basic shadow map that encompass whole scene statically. This means that shadow map texel size in light view ...
- 2,119
7
votes
Accepted
WebGL Omnidirectional Shadow Mapping Issue
SOLUTION
After a couple of days I realized that I was computing my projection matrix using a FOV angle in degrees and It should be in radians. I made the conversion and now everything works great. ...
- 171
5
votes
Accepted
How should I generate the view position for a light at infinity when creating depth maps?
Instead of using a perspective projection you would use a orthographic projection.
Then the trick is to position the bounding box to in front of the normal camera.
An additional option is to add a ...
- 5,920
5
votes
Why is OpenGL recompiling my depth map vertex shader based on the GL state?
This is an example of implementation details leaking through the abstraction. Parts of the GL state are often implemented via native GPU ISA instructions that the driver injects into user-defined ...
- 882
3
votes
Accepted
Artifacts in omni light shadow mapping
I finally found the cause of the problem. There appears to be a problem with the shadow map of both the omni light and spotlight. While debugging, I noticed by accident that the light-view-to-light-...
- 1,044
3
votes
In forward rendering what's the go to technique to smooth out rigid shadow due to low resolution shadowmap texture?
Ah, shadows. They still are bothering after so many people spent years trying to improve them.
Whether your engine is deferred or forward, the shadow pass should be quite the same, and suffer the same ...
- 1,851
3
votes
Accepted
In forward rendering what's the go to technique to smooth out rigid shadow due to low resolution shadowmap texture?
Percentage Closer Filtering with some amount of blur (ie. a minimum filter size in texture space) is the most basic method I know of. For example, see GPU Gems. My experience is that it is also quite ...
- 1,585
3
votes
Accepted
How are hard and soft shadows cast?
Hard shadows are simple that only needs a point light.
How it's done is by rendering the scene from the point of view of the light and only keep only the depth information. This is the shadow map.
...
- 5,920
2
votes
Accepted
Shadow map projection issue
One of the downsides to shadowmapping is that you need to offset, or bias, the point used for shadowmap-lookups. This is done in a variety of ways - typically by a constant (shadowmap-depth) distance ...
- 471
2
votes
In forward rendering what's the go to technique to smooth out rigid shadow due to low resolution shadowmap texture?
One technique is adaptive shadow maps where you use a low resolution map for shadows that are rendered far away from the camera, a mid-resolution map for stuff that's in the mid range, and a high ...
- 3,401
2
votes
Accepted
How to use shadow mapping and deferred rendering to create a large amount of lights?
Deferred rendering does not have an asymptic complexity of O(lights+fragments). It has a complexity of O(fragments+visibleFragments*lights).
What you are doing in deferred rendering is preventing ...
- 588
1
vote
Accepted
Why doesn't using depth biasing to fix shadow acne result in an even bigger problem?
The book "RAY TRACING GEMS (1)" from Nvidia has a whole chapter about avoiding self-intersection. I highly recommend this book because they show different methods about all parts of problems ...
- 1,136
1
vote
Accepted
Cascaded Shadow Mapping (CSM), Partitioning the Frustum to a nearly 1 by 1 mapping
The logarithmic shadow mapping split scheme produces split points that minimize aliasing. There is a short derivation that can be used to show that it produces the split points that reduce aliasing to ...
- 3,030
1
vote
Accepted
Reducing Cascaded Shadow Mapping Artifacts
Getting high quality shadows from Cascade Shadow maps with (relatively) low resolution shadow maps is a process. I recommend taking on different aspects one at a time.
Here are few generic suggestions....
- 3,030
1
vote
Accepted
ShadowMap peter-panning and wrong direction
I found out that simply removing minus sign in shader in converting coords to [0, 1] solved direction problem. But scale is still off - here is an example:
...
1
vote
Accepted
R16_FLOAT, SampleCmp and CheckFormatSupport
Because I was using the CheckFormatSupport wrong. The second parameter is supposed to be an input.
Here is what it should be like.
...
- 115
1
vote
Accepted
What does "region to be shaded" mean in the PCF paper?
Texture mapping is the process of providing a mapping from the surface to a location on the texture. That is, given a particular point on a surface, you can find a specific point in a texture that ...
- 9,697
1
vote
Accepted
DX9 Shadow map PCF issue
It seems that sampler2D_float doesn't allow to interpolate shadow lookup linearly. So I had to do it by hand. Here's an example of interpolated shadowing.
...
- 1,219
1
vote
How are hard and soft shadows cast?
@ratchetfreak's answer describes shadow mapping, however, there's another not so difficult to implement way of drawing hard shadows. The shadow volume technique uses extruded geometry plus some ...
- 1,459
1
vote
What is this shadow mapping error called?
It's not entirely clear what the scene in your picture is supposed to look like, so I'm not sure I'm interpreting it correctly. But if I am, it seems like the problem is that you're projecting the ...
- 3,401
Only top scored, non community-wiki answers of a minimum length are eligible