Skip to main content
Share Your Experience: Take the 2024 Developer Survey

Questions tagged [shadow-mapping]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
15 votes
2 answers
2k views

Handling Projective Aliasing In Shadow Mapping

I'm fiddling with simple procedural 3D modeling to make teeny buildings for 3D printing. An Example: To make the models more readable onscreen, I've implemented basic shadow mapping for a single ...
user avatar
10 votes
1 answer
1k views

WebGL Omnidirectional Shadow Mapping Issue

First of all, I want to say that I've read a lot of post about shadow mapping using depth maps and cubemaps and I understand how they work and also, I have working experience with them using OpenGL, ...
czapata91's user avatar
  • 171
9 votes
1 answer
2k views

Shadow Mapping artefacts

I've been playing around with shadow mapping in OpenGL using depth textures. The depth texture is fine and I can map it onto the scene but I have some strange artefacts on the back of the object: My ...
Blarglenarf's user avatar
7 votes
1 answer
249 views

Shadow map projection issue

I am using Unity but this question might not be proper to this engine. I have projected the shadow map onto this sphere but there are grazing shadows. Is it possible to avoid it or to correct it as I ...
MaT's user avatar
  • 1,229
6 votes
1 answer
174 views

How should I generate the view position for a light at infinity when creating depth maps?

I'm working on implementing Bruneton's cloud rendering paper, which requires one to render a pair of depth maps, similar to how shadow mapping works. In this case, my light source is the sun (or ...
stix's user avatar
  • 163
6 votes
1 answer
289 views

How to render an object that recieves shadows but does not cast them in a variance shadow mapping system?

I'm currently preparing to implement variance shadow mapping based on this article. However, one point it makes concerns me: Rendering only casters (and not receivers) into the variance shadow map ...
user avatar
6 votes
0 answers
1k views

Cascaded shadow maps. Seams between cascades

I implemented cascaded shadow maps, where shadow maps for each cascade is rendered to one canvas: The light projections for each cascade are calculated from the bounding spheres of camera sub-...
Zheden's user avatar
  • 161
5 votes
3 answers
301 views

In forward rendering what's the go to technique to smooth out rigid shadow due to low resolution shadowmap texture?

I am building my own graphic engine. My depth texture is significantly smaller than that of the screen. The low resolution depth map results in rigid shadow like this... I am sure this is a common ...
Blue Bug's user avatar
  • 321
5 votes
0 answers
1k views

Percentage-closer Soft Shadows implementation

I am trying to implement the Percentage-closer Soft Shadows (PCSS) from NVidia inside Unity but I am facing some issue and I don't know where they come from and then, I do not know how to solve them......
MaT's user avatar
  • 1,229
4 votes
1 answer
2k views

Why is OpenGL recompiling my depth map vertex shader based on the GL state?

I've written a shader that writes depth to each face of a cube map, as part of rendering cube map shadows for a realtime 3D engine I'm writing with OpenGL and C++. The shader transforms each vertex ...
b1skit's user avatar
  • 161
4 votes
2 answers
140 views

Storing shadow data

Given a 3D space and a light source, I use ray casting to determine the shadows generated in the scene. If I'm to store the shadow data (boundary of the shadow, object which cast the shadow, etc.) ...
ichigo1191's user avatar
3 votes
2 answers
1k views

How are hard and soft shadows cast?

I have been studying computer graphics, from the book Fundamentals of Computer Graphic (but the third edition), and I lastly read about texture mapping and shadow maps. Though, I didn't exactly ...
phong's user avatar
  • 265
3 votes
1 answer
175 views

What is this shadow mapping error called?

I have been following a tutorial, shadow mapping works more or less as expected except sometimes the shadow projects completely weirdly on nearby walls. This isn't sampling outside the lightmap ...
Kachinsky's user avatar
  • 131
3 votes
0 answers
214 views

Projective Texture / Shadow Mapping -- Why is the perspective division performed in the fragment shader?

I've just worked my way through this OpenGL shadow mapping tutorial. While I understand the basic algorithm, one thing puzzles me: During the 2nd render pass all vertices are transformed into the clip ...
rapunzel's user avatar
3 votes
1 answer
138 views

How can I use multiple texturing with shadow mapping?

So, recently I followed this tutorial about shadow mapping, but in the tutorial it doesn't texture the object.. When I try to add a texture, it's distorted by the ...
Bla...'s user avatar
  • 481
2 votes
1 answer
389 views

Artifacts in omni light shadow mapping

Spotlight My spotlight's intensity is cut off at a distance of 3 and at an angle of $\pi/4$ radians (umbra angle). The corresponding light camera has a near plane at a distance of 0.1, a far plane at ...
Matthias's user avatar
  • 1,074
2 votes
1 answer
331 views

R16_FLOAT, SampleCmp and CheckFormatSupport

I want to use PCF shadow map on my d3d11 app. My shadow map is an R16_FLOAT texture. When I use SampleCmpLevelZero it didn't give a correct result. After enabling debug layer, it shows: The Shader ...
ACskyline's user avatar
  • 115
2 votes
1 answer
334 views

DX9 Shadow map PCF issue

I am trying to do simple PCF with Unity but I am facing some issues and I don't know where they come from. If anybody has an idea... Here are two examples ...
MaT's user avatar
  • 1,229
2 votes
0 answers
84 views

How can you efficiently get the last element occluding light when rendering shadows?

A long time ago I made an application that used volumetric rendering and I developed some shadowing equations that I felt very happy with, since they have pretty good results. For these equations to ...
Makogan's user avatar
  • 1,726
2 votes
1 answer
3k views

How to decompose projection matrix?

I want to decompose projection matrices into near, far, top, bottom, left and right values to create a bounding box for view frustum. I used the formula described in this site Decompose the OpenGL ...
recp's user avatar
  • 185
1 vote
2 answers
702 views

Reducing Cascaded Shadow Mapping Artifacts

I've been trying to get my cascaded shadow maps looking right for a while. I managed to fix the shimmering and most of the quantization artifacts, but for some reason the shadows still look really ...
Josh Lakin's user avatar
1 vote
1 answer
123 views

Why doesn't using depth biasing to fix shadow acne result in an even bigger problem?

I am currently reading the Ray Tracing in One Weekend tutorial (link), and I am dubious about their fix for shadow acne, which is to ignore ray-geometry intersections that occur at very small times. ...
Christopher Miller's user avatar
1 vote
1 answer
239 views

ShadowMap peter-panning and wrong direction

I am creating Forward-Rendering DX11 engine and I have some troubles with shadow-mapping algorithm as it doesn't work as supposed. As you can see - shadow is peter-panning and looks totally not ...
DirectX_Programmer's user avatar
1 vote
1 answer
99 views

What does "region to be shaded" mean in the PCF paper?

I am reading the percentage closer filtering (PCF) paper by Reeves, W. et al. (https://graphics.pixar.com/library/ShadowMaps/paper.pdf). At at section 3.2, it mentioned that "each shading calculation ...
yuchen's user avatar
  • 475
1 vote
0 answers
153 views

Convolution shadow mapping apply filter

I've implemented the convolution shadow mapping technique (CSM) and want to apply a gaussian filter to receive soft shadows. The filter size of the filtered pixels is not static. With help of a summed ...
Thomas's user avatar
  • 1,265
1 vote
0 answers
95 views

ShadowMap artifacts when moving on the map

I have a problem which I believe is caused by the fragment shader code I use, however I'm not entirely sure. The issue is this: I’ve been playing with few examples using Cesium (3D globe) and ...
C Clarke's user avatar
1 vote
1 answer
287 views

Receiver plane depth bias - matrix explanation / derivation

This source on slide 38 on receiver plane depth bias I can find compute a matrix (Jacobian of screen space uv derivatives) which is used to transform the screen space depth derivatives from screen ...
cg_guy420's user avatar
  • 115
1 vote
1 answer
75 views

Doubt about Light space transform (Shadow map)

at this moment I am learning to do shadow mapping in webgl2.0, i was able to generate my first shadows in my 3D scene but I have a couple of doubts to clarify. This is the way im calculating my light ...
Luigi Pocay's user avatar
0 votes
1 answer
80 views

How does ray tracing handle the calculation of reflections and shadows in the presence of multiple translucent objects?

Raytracing can handle the interaction between light and multiple translucent objects in a scene by using global illumination and raytracing with volumetric effects to calculate the color of the object ...
Arunabh Bhattacharya's user avatar
0 votes
1 answer
532 views

How to use shadow mapping and deferred rendering to create a large amount of lights?

Ok so I am trying to understand how to combine these 2 techniques and I am failing. The main goal is to reach the O(lights+fragments) complexity of deferred rendering, instead of O(lights*fragments) ...
Makogan's user avatar
  • 1,726
0 votes
1 answer
158 views

Cascaded Shadow Mapping (CSM), Partitioning the Frustum to a nearly 1 by 1 mapping

I am trying to implement CSM technique with "Fit to Cascade" projections. My problem is to find good distances to partitioning the cameras view frustum. The FoV of my camera is changing, so ...
Thomas's user avatar
  • 1,265
0 votes
0 answers
74 views

Shadow mapping with non-directional light

I'm new to openGL and I was following this tutorial in which they showed how to make shadow maps but I could't understand how to get it to work for non-directional lights. They have some instructions ...
n-l-i's user avatar
  • 101
0 votes
1 answer
342 views

Unity - custom shadow from sun

due to some features in materials I need to create my own directional shadow map. Everything seems to work ok, until the moment where I compare depths. First I add camera component to directional ...
Derag's user avatar
  • 596