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How to have caustics at all in a path tracer with next event estimation?

When doing next event estimation, you trace a shadow ray to a light source to test visibility. What if there's a glass/transmissive object in the way? The light will be occluded and we won't get any ...
Tom Clabault's user avatar
0 votes
0 answers
24 views

Change the shape of the caret in ImGui

I would like to change the shape of the caret in ImGui, either to a wider one or to an underscore. I'm not sure where to start. I would also like to change the blinking rate if possible. Thanks for ...
Bartolini's user avatar
0 votes
0 answers
21 views

Solidworks, does a one-year license automatically renew if I don't terminate the agreement? [closed]

I have a question regarding the one-year license for Solidworks software. I would like to know if my license automatically renews after one year if I don't terminate the agreement. I have reviewed the ...
Mantykora 7's user avatar
0 votes
0 answers
27 views

Monitor Height *Requirment

Sorry if this is the wrong place to ask this question. I'm registering to get remote proctoring on a test, but my monitor height is too small (according to the program they use for this proctoring). ...
Tiler99uu's user avatar
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0 answers
22 views

Multiple Importance Sampling BSDF + Light - weights confusion with the number of emissive triangles

I'm trying to implement multiple importance sampling for direct lighting estimation but I'm having a hard time understanding why adding the number of triangles to the PDF of my light sample yields ...
Tom Clabault's user avatar
0 votes
1 answer
15 views

Clarification on PPI

I wanted to convert a chart rendered by canvas element to an image file so that the user can download it. But the official HTML docs say that: The created image data will have a resolution of 96dpi ...
Urooj's user avatar
  • 111
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0 answers
16 views

PPM P3 has different pixel values but appears to be in uniform color

I have generated a PPM P3 file using C++. Even though the pixels are different, when I open the file in a text editor, it appears to be of only one color in my preview program. What is the problem? <...
Kotaka Danski's user avatar
1 vote
1 answer
37 views

Blinn-Phong specular light bleeding on triangles facing-away from light: what is the canonical solution?

In our implementation of the empirical Blinn-Phong shading model, we are facing a problem with light-bleeding of the specular component. The model defines the half-vector $\vec{h} = \frac{\vec{v} + \...
Ad N's user avatar
  • 111
2 votes
1 answer
53 views

How is Shader Execution Reordering implemented under the hood?

I am writing a software path tracer from scratch in CUDA (for learning purposes, without resorting to any higher-level graphics API like OptiX), and it is well-known that path tracing can have ...
Enigmatisms's user avatar
  • 1,012
0 votes
2 answers
68 views

How are surface normals dealt with in the graphics pipeline?

I know the process for regular vertices is something like: model coordinates to clip space via the "MVP" matrix transformation, then perspective division, screen-space mapping, and finally ...
Scene's user avatar
  • 157
1 vote
0 answers
32 views

How to get the shortest segment AB between 2 SDF (Signed distance field) in 3D?

Is there a method to find the shortest segment between 2 Signed distance field? I know how to calculate this segment for a limited number of SDF like from sphere to sphere, from capsule to sphere, ...
Kuwazy's user avatar
  • 11
2 votes
1 answer
38 views

Would there be a point in creating monitors that have more than the regular RGB color channels?

I was thinking about color spaces and the coverage between the sRGB and Lab color spaces such as OkLab. I was wondering if there could exist some different monitor technology with more than 3 color ...
FatBaz's user avatar
  • 21
0 votes
0 answers
35 views

Is there a more extensive collection of OpenGL materials? [closed]

I develop a modeling program where users can choose from a set of predetermined OpenGL materials or enter their own custom materials. I would like to expand the list of predetermined materials ...
Rob McDonald's user avatar
0 votes
1 answer
34 views

How are these two projection matrices related?

I have two 3D perspective projection matrices $A,B$ with standard projection parameters $k=\cot(\theta/2)$, where $\theta$ is the field of view, $n$ is the $z$-near value, $f$ is the $z$-far value, ...
Scene's user avatar
  • 157
3 votes
1 answer
45 views

What to do with the homogeneous $w$ during vector operations

As I understand it: In graphics, 3D vectors are usually represented as homogeneous coordinates by storing an additional $w$ component known as the weight. The vector is divided by $w$ to obtain the ...
Scene's user avatar
  • 157
0 votes
1 answer
42 views

what technicalities involved in screenshot process? what is the dependency of screen properties in the screenshot of an image?

If we take screenshot of image displayed on a monitor screen, then does it take only framebuffer data? Does the framebuffer data is independent of display screen properties like contrast, brightness? ...
Techie's user avatar
  • 1
2 votes
1 answer
30 views

Possible reason for buffer orphaning being faster than using glBufferSubdata even when changing the size of that data?

I recently conducted an experiment, where a large scene was split into two types of mesh data - static (the terrain) and dynamic (lots of low poly trees). I evaluated two memory layouts and update ...
rbaleksandar's user avatar
0 votes
0 answers
9 views

DrawArrayInstanced is not rendering what it should (OPENGL)

...
EnVadeh's user avatar
0 votes
0 answers
10 views

Issues with vxgi implementation when rotating the camera

right now I have implemented vxgi algorithm. Voxelization is working fine, same for mipmap generation. But, I have an issue when I rotate the camera. Basically, it is not stable when it is rotated. I ...
Zhukov Artem's user avatar
0 votes
1 answer
28 views

How to achieve smooth max of two coordinates in a shader

I am trying to achieve a border effect to a square tile on a xz plane. I am using max of coordinates x and z to achieve that. Here is my ShaderLab code: ...
hungry91's user avatar
1 vote
1 answer
50 views

Is the light emitted by a typical white pixel actually a blue-ish purple to compensate for our greater sensitivity to the color green?

The human eye is considerably more sensitive to green light than red or blue; this is expressed in formulae which calculate an approximate overall "luminance" value for a RGB color (example)....
jameswilddev's user avatar
0 votes
1 answer
46 views

Pose representation using rigid transformations

In literature (3D graphics, computer vision, 3d deep learning etc.) I notice that often an object's pose is represented using a rigid transformation, i.e a member of the group SE(3) combining a ...
giorgio's user avatar
  • 133
0 votes
1 answer
90 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's user avatar
  • 103
0 votes
0 answers
26 views

Is it possible to use OpenGL ES extensions in OpenGL? If not, why?

I've been looking at KHR_texture_compression_astc_hdr for OpenGL. It seems it's only currently supported by OpenGL ES 3.2. My GPU is an Nvidia RTX A3000, which does ...
Cascades's user avatar
  • 113
1 vote
1 answer
72 views

Is there a quicker way to draw a symmetric, scale-invariant (declining color) gradient around an ellipse?

The goal is to generate a picture like this: A symmetric color gradient around an ellipse which is rotated by $\theta$, has $(x_\circ,y_\circ)$ as center and and major and an minor axis $a,b$. The ...
UncleBob's user avatar
1 vote
1 answer
44 views

In perspective projection matrices, why isn't $z_\text{eye}$ mapped linearly to NDC?

As far as my understanding goes, in projection matrices $x_\text{eye}$ and $y_\text{eye}$ are mapped linearly to NDC by first using proportions to find $x_n = \frac{n\cdot x_e}{-z_e}$ and $y_n = \frac{...
blvck_mvgic_dot_exe's user avatar
0 votes
0 answers
27 views

Unit tests and code coverage tool for GLSL compute shaders

I use some compute shaders for some GPGPU usage. Each method of each shader must have unit tests. These unit tests must cover more than 95% of the code. I am looking for tools that I can use to write ...
Thomas's user avatar
  • 1,295
0 votes
0 answers
12 views

Tools to identify the cyclomatic complexity of GLSL code

In principle, cyclomatic complexity is a quantitative measure of the number of linearly independent paths through the source code of a program. I am forced to keep the cyclomatic complexity of our ...
Thomas's user avatar
  • 1,295
2 votes
0 answers
29 views

Algorithm to extract key points from line drawing

I have orthographic 3-view black and white line drawings like this: I would like to extract a set of 'key points' from this kind of drawing. By 'key point', I mean corners and a few points along ...
Rob McDonald's user avatar
1 vote
0 answers
36 views

Projecting a texture onto UVs with GLSL

I am trying to project an image overlayed on top of a mesh in screen space back to it's uvs. The UV triangles do not always cover entire pixels so i get this. The red is showing where the texture is ...
Dusan Bosnjak 'pailhead''s user avatar
1 vote
1 answer
39 views

Distance sampling with unbiased transmittance estimators

I'm currently trying some things with transmittance estimators in PBRT and I have implemented the following paper: Unbiased Ray-Marching Transmittance Estimator. This method assumes that two points $x$...
Matthias K.'s user avatar
1 vote
0 answers
70 views

What is the fastest way to rasterize a triangle?

I'm making a triangle rasterizer for my 3d engine because I forgot to make a depth buffer and I was wondering what is the fastest way to rasterize a triangle, I was thinking bresenham combined with ...
samone123's user avatar
1 vote
0 answers
33 views

Automating equirectangular horizon detection in 360 images

I would like to programatically identify pitch and roll numbers that will level the horizon on each frame in a series of equirectangular 360 panorama images. Here's why. I recently ended up with a ...
amh15's user avatar
  • 111
2 votes
1 answer
52 views

Direct Light Sampling produces way too bright images compared to naive diffuse bounces only

it's me again! :D I have finally implemented area lights, but without modifying the emission value of the material, this is what it looks like with indirect light only, this is what it looks like with ...
Syrinxos's user avatar
1 vote
1 answer
84 views

How to include SPIRV in a CMake project

SPIRV Cross How do I include this in my project I added this to my packages folder ...
GloriousDemonFist's user avatar
0 votes
1 answer
33 views

Getting linking error while testing to add vulkan shaderc in my project

CMakeLists.txt find_package(Vulkan REQUIRED) target_link_libraries(${PROJECT_NAME} INTERFACE Vulkan::Vulkan) in my shader.cpp ...
GloriousDemonFist's user avatar
0 votes
0 answers
68 views

Do Euler Angles always cause Gimbal Lock?

I am learning about euler angles, and read about gimbal lock. I read that representing rotations with euler angles can always cause gimbal lock. All the examples that I saw on the internet show an ...
Mykhailo Seniutovych's user avatar
1 vote
0 answers
26 views

How to morph a enclosing mesh according to the enclosed mesh?

I am quite new to meshing and mesh manipulation. I am working on a problem consiting of meshes $A$, $B$, and $C$. The mesh $C$ completely encloses the meshes $A$ and $B$ as shown in the attached ...
Prakhar's user avatar
  • 11
1 vote
1 answer
57 views

Why does lv = fract(uv*2) result in grid like pattern?

Here is a shader in GLSL that visualizes the normalized pixel coordinates (from 0 to 1): ...
kyopa's user avatar
  • 141
0 votes
0 answers
15 views

BC1 code decoding for texels

I want to implement a BC1 decoder. A single BC1 compressed block consists of 64-bit, where bits are stored like this: ...
efe373's user avatar
  • 1
0 votes
0 answers
12 views

Reflective shadow maps sampling

I'm following the old RSM paper and I don't understand the sampling section. I understand that it's a disc pattern, that is more scattered away from the center and has some weights. I don't understand ...
Dusan Bosnjak 'pailhead''s user avatar
2 votes
0 answers
28 views

How does this wormhole effect shader create a distortion?

Below is the code for a simple wormhole effect shader made in shadertoy.com. I understand everything else except: ...
kyopa's user avatar
  • 141
1 vote
0 answers
38 views

How to create a more photorealistic ocean?

Photorealism has many elements. Take, for instance, the figure 1 below, a shot from Dune Part One movie. Figure 1 The process of production of a image such as this one, is laborious and involve more ...
M.N.Raia's user avatar
  • 111
1 vote
1 answer
30 views

Vertices are mapped to UV coordinates, but how does the shader access the UV data?

So in every mesh, the vertices can have UVs, and UVs are a way to store data for each vertex. Basically, at the time of rendering, when the shader runs, it's a way to check some arbitrary data for ...
kyopa's user avatar
  • 141
0 votes
1 answer
96 views

What are some ways of modelling data for GPU side where e.g. OOP is not available?

I'm currently on a journey of writing a basic path-tracer. My current implementation uses fragment shaders to run the path tracing algorithm per pixel. I am at the point where I need to start ...
unusually_crispy_crisps's user avatar
0 votes
0 answers
14 views

Determine horizontal FOV of a panoramic photo

Say I have a panoramic photo (less than 360) and would like to view it in a cylindrical screen in a VR headset to get an immersive experience. How to determine the optimal width and height of the ...
Jack Guo's user avatar
1 vote
0 answers
23 views

text-rendering: why alpha testing produces wavy edges. And why SDF solves that problem

My first question is almost identical this one. I originally became aware of this when reading Valve's paper on using Signed Distance Field (or SDF for short) as seen here: However, I would really ...
Serilena's user avatar
0 votes
1 answer
43 views

Who does the actual drawing when I call openGL draw API?

I am sorry if the question is too basic but I am just starting with the graphics library. My question is when I invoke draw API in openGL who does the actual job of drawing/coloring of the actual ...
Himanshuman's user avatar
1 vote
1 answer
89 views

Why is my ray tracer not accelerated by CUDA?

Summary: I ported a simple path tracer smallpt into CUDA but the performance doesn't boost. reproduce results: build and run the CPU version: ...
Rahn's user avatar
  • 183
-1 votes
1 answer
63 views

Drawing Feynman diagrams

I am working on my MSc thesis on Quantum Electrodynamics. I have to draw some Feynman diagrams for Compton scattering and similar processes, for which I want to use Microsoft Visio. I am having a hard ...
Anant Badal's user avatar

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