Questions tagged [c++]
The c++ tag has no usage guidance.
2
votes
1answer
48 views
Confusion about data types in Jensen's subsurface scattering paper
I am currently trying to implement Jensen's paper on subsurface scattering, but I am getting confused when I am trying to implement it in my pathtracer. I have questions about the data types of ...
2
votes
0answers
85 views
HalfEdge data structure in openmesh, create_face function explanation
Does anyone have experience with open-mesh or computational geometry and can kindly explain what exactly happens in the function below?
...
0
votes
1answer
96 views
smallpt: ray scattering and Importance Sampling
Introduction
For those familiar with smallpt by Kevin Beason:
In path tracing, when rays hit a surface, they are scattered and the theta angle (the angle between the normal to the surface and the ...
1
vote
1answer
88 views
smallpt: when to stop diffuse ray scattering
For those familiar with smallpt, the ray tracer in 99 lines: I am checking the code, and there is something that is not clear to me in the DIFFUSE ray scattering.
After the rays are shot, they keep ...
1
vote
0answers
22 views
Help with efficient quadtree vertices indexing to avoid redundancy
I am creating a quad tree from ground zero, because I am going to collapse it from bottom up I am refining it with a certain LoD level.
I am using glm for mathematics and opengl for rendering. ...
5
votes
0answers
127 views
How to account for self intersection with large ray tracing scenes?
I'm working on a hybrid real time ray tracing project and trying to tackle the problem of self-intersection with larger scenes due to loss of float accuracy. The logic I'm trying to use is based on ...
0
votes
1answer
113 views
Monte Carlo Importance Sampling
I am following the "Ray Tracing - the Rest of your Life" book by Peter Shirley and I am facing some troubles in the implementation of Monte Carlo importance sampling, and Direct light sampling.
Monte ...
-2
votes
1answer
89 views
This function syntax is confusing me
gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)
I have never seen this syntax before. Presumably glfGetProcAddres is a function, but it has the brackets behind it. Is this only possible in open gl ...
0
votes
1answer
81 views
Ray tracing the next week: understanding Instances
My question is not about the code, but it's about the approach used by the author Peter Shirley (and apparently common practice in ray tracers) of handling Instances. To understand the question it's ...
1
vote
1answer
91 views
How can I control memory for command allocators and command queues in D3D12?
The D3D12 programming guide suggests specific allocation strategies for command queues and allocators, but the creation methods for those objects operate directly on queue/allocator pointers without ...
1
vote
1answer
69 views
OpenGL Unable to retrieve the values of data sent to shader using textures
I've been following these tutorials and i can't figure out how to send data to shaders using textures.
https://en.wikibooks.org/wiki/OpenGL_Programming/Scientific_OpenGL_Tutorial_02
In this tutorial ...
1
vote
1answer
148 views
Do I need separate Graphics and Transfer commands?
I was following this tutorial on Vulkan https://vulkan-tutorial.com/Vertex_buffers/Staging_buffer and I decided to do this bit:
The buffer copy command requires a queue family that supports ...
1
vote
1answer
451 views
How do I create a Win32 window with a Vulkan context?
I am aware of libraries that already do this (like GLFW), but I would actually prefer do all of the window and context creation by myself.
3
votes
0answers
228 views
ray-triangle intersection precision - c++
I'm building a software renderer but I think there might be some problem with my ray-triangle intersection accuracy.
I implemented the algorithm referring to ...
0
votes
1answer
93 views
qt - view geomview (.off ) file
I want to open a .off file and view the content 3d model using libQGLViewer, qt-creator.
I don't know how to display the 3d model after opening its .off file.
...
-1
votes
2answers
115 views
Relatively new to OpenGL, need guidance/tips on an assignment with interactive user input
I'm currently taking a Computer Graphics class at university, and have been given an assignment which involves loading an obj file and manipulating it with keyboard and mouse controls (eg. arrow keys ...
2
votes
1answer
80 views
Why does DirectX use COM pointers and interfaces?
I have a rudimentary understanding of COM and I know that its main purpose is to enable interoperability between programs written in different languages. However I dont understand why that is useful ...
0
votes
0answers
45 views
How to ensure that the raytrcing coordinate system is teh same as the projection one?
I have 2 shading models right now, one is using voxels the other one is the standard projection absed renderization method.
Putting them side by side I have noticed that no matter what I do one is ...
1
vote
1answer
53 views
Can you avoid querying for a texture location in OpenGL?
The way I learnt to send a texture to a shader is more or less
...
2
votes
1answer
310 views
Weird artifacts in my ray tracer
I am getting weird artifacts in my simple ray tracer that I made using the book Ray Tracing in One Weekend by Peter Shirley.
Example:
(circular pattern on the ground and black tint on the spheres.)
...
1
vote
0answers
38 views
Handling varying texture sizes in an array texture
Say we've idetified that we have a varying number of textures that are upper capped by 2 parametrs. thus we allocate the maximum amount of memory needed to store all textures as follows:
...
0
votes
1answer
300 views
Opengl black screen for a simple translation
i am a beginner to opengl following an online guide,
I am trying to make a simple translation to my triangle.
The triangle did render correctly when i made a float uniform to translate it, but when i ...
0
votes
1answer
145 views
Distorted OpenGL graphics in certain models of Intel GPUs under Windows; possible causes?
I'm not sure this is the best place to post this, but it definitely seemed more appropriate than programming. I'm one of the developers of Performous, essentially a karaoke (and instruments) game. We ...
1
vote
1answer
199 views
Issues with Multi-threaded Raytracing
I'm having some issues with my multi-threaded ray tracing implementation. It seems to only render about half of the image. Here is the picture:
Here is the code:
...
1
vote
0answers
86 views
Adding Ozone to my sky simulation
I implemented a simulation for the colour of the sky a while ago by following the scratch a pixel tutorial: https://www.scratchapixel.com/lessons/procedural-generation-virtual-worlds/simulating-sky
I ...
5
votes
1answer
459 views
Inverse value in a Perspective Matrix
I am a new leaner of computer graphics. I'm trying to understand a code I found online and I got stuck in the following formula:
...
1
vote
0answers
68 views
Image Processing: Photogrammetry [closed]
I am new to image processing but I am currently exploring myself in 3D reconstruction during my leisure time.
I have decided to use openCV (eg. edge detection, possible?) in C++., maybe with a little ...
2
votes
1answer
196 views
Histogram of image intensities
I want to create a histogram of intensities 0.1, 0.2, .... 0.9, 1, from an image rendered using OpenGL and C++. How can I do this? Can I access the pixel intensities in the framebuffer somehow? Also, ...
2
votes
2answers
573 views
I'm trying to get a 2D screen position so I unproject a point from 3D into 2D screen coordinates by that following function:
I'm trying to get a 2D screen position so I unproject a point from 3D into 2D screen coordinates by that following function:
...
1
vote
0answers
269 views
How to properly release directx com objects
This one I am not getting even one bit.
I started learning directx11 and using the basic dx initialization i tried a experiment by allowing an option to destroy the window and creating it again ...
1
vote
1answer
639 views
Vulkan best way of updating pipeline viewport
I have discovered that there are two ways to update the viewport (might be more, but not sure). Currently I am rebuilding the Pipeline when I resize my screen but there is a noticeable stutter as it ...
1
vote
0answers
406 views
360 degrees rotation around x axis
How do we rotate the camera around x axis 360 degrees, without having to flip the axis, meaning without having the strange flip after we go over +-90 degrees on <...
1
vote
1answer
124 views
How do I handle uniforms in a deferred renderer?
I'm currently working on a renderer that tries to minimize the amount of state changes when drawing objects.
During each frame the client submits draw instances (the client provides a render state (...
3
votes
1answer
652 views
Please, help me to understand why my raytracing camera rotates in wrong directions?
I'm trying to build a raytracer and I use this article on how to build camera system. The problem is that when, after calculating ray direction in camera space, I multiply it by camera-to-world ...
1
vote
2answers
285 views
How to use multithreading in 3D software renderer to speed up fetching texture values
The biggest bottleneck of my code is fetching texture RGB values from memory.
My code looks something like this:
...
1
vote
0answers
112 views
Finding Segments in Continuous line
I'm trying to break a continuous line segment into multiple, straight segments.
I've tried using the Hough transform but have found it unreliable for getting the line segments I'm looking for and ...
5
votes
0answers
133 views
Computation of conservative AABB for clipped triangle
I'm currently trying to implement a fast algorithm for KD-Tree construction using SAH, as described in this paper:
On building fast KD-trees for ray tracing, and on doing that in O(N log N)
I found ...
2
votes
0answers
116 views
Image Laplacian incomprehension
I am reading and trying to implement a research paper.
It uses openGL to define which part of an image to use in order to reconstitute a big image composited of several images.
In order to do so, I ...
2
votes
1answer
353 views
Jos Stam's “Stable Fluids” boundary conditions
In the paper Stable Fluids by Jos Stam, I am confused about the boundaries in the set_bnd function in the code. I don't know what kind of boundaries is this. Is it Neumann boundary condition or ...
1
vote
1answer
604 views
How can I utilize all cores of CPU In my ray tracer with std::thread?
I have been working on a ray tracer and I was trying to use multiple threads to maximize the performance. I tried couple of approaches but there's no difference in performance. Here's my shot...
<...
3
votes
0answers
366 views
Problem with specular BRDF (Monte Carlo & Path Tracing)
Above on the left is my attempt and on the right is what I'm aiming for.As you can see my sphere with the specular brdf has a weird dark ring
In my radiance function I am recursing through the ...
4
votes
2answers
182 views
2
votes
2answers
386 views
Can somebody explain this Ray Tracing Function?
I am currently reading through Peter Shirley's Ray Tracing in One Weekend. In the beginning chapters where the author introduces diffuse surfaces we a presented with this function:
...
1
vote
1answer
623 views
Skia example code not writing an image
I am just trying to make a simple Skia program. A very simple program, but as I run this code, the output image file never writes anything. I am running this code on VS 2015 and included the skia.lib ...
4
votes
1answer
112 views
NormalMap problems: bumps work, but shade does not
I've been trying to figure this out for a few days now, but I just can't get it right. I've read multiple tutorials and possible explanations, I even watched a java tutorial without finding the ...
1
vote
1answer
193 views
How to organize Lights and Models?
I'm interested in how to organize in code (I prefer C++) lighting.
Problem is: I have Scene which contains Model where model ...
1
vote
1answer
173 views
My (ADS) shader doesn't render the light direction correctly
This is what I'm doing:
vertex shader:
...
1
vote
1answer
303 views
Am I passing the correct matrices for my shader? openGL/C++
On page 89 of David Wolff - OpenGL 4.0 Shading Language Cookbook book, it suggests a way to set up up a Phong shader in the fragment stage. It lists some different matrices to pass via uniform, and I ...
1
vote
1answer
249 views
Swap buffers twice does not show the first scene
If you clear the color buffer and draw a triangle, you have nothing in the buffer that is shown in the screen and a triangle in the other buffer, so you have to swap buffers for showing the triangle. ...
7
votes
2answers
469 views
How to handle a parametric equation in raytracing?
After taking a look at the Mobius strip, I noticed its equation is really simple and tried to add it into my Raytracer.
I tried a "naive" way by simply generating N...
