Questions tagged [c++]
General-purpose programming language used widely in game development and CPU-intensive tasks.
200
questions
2
votes
2
answers
1k
views
How to watch image being ray traced?
In my ray tracer, I render my images out to a .PPM file and then view it in photoshop. To make things easier and faster I want my ray tracer to open up another window and show the image being rendered ...
- 2,473
3
votes
1
answer
2k
views
18
votes
1
answer
6k
views
What does "makeContextCurrent" do exactly?
I am pretty confused about that function. GLFW Context reference says as follow:
This function makes the OpenGL or OpenGL ES context of the specified
window current on the calling thread. A ...
- 647
2
votes
3
answers
990
views
Is there a difference between window and screen in computer graphics?
I've been reading some code which setups a ray tracer and I've realized I've a doubt regarding what's a screen and what's a window in this context. Here's the relevant code using Qt:
...
user4718
5
votes
1
answer
3k
views
Modern way of light sources in OpenGL?
In older versions of OpenGL there were things like:
glLight(...)
gl_LightSourceParameters
The modern way of doing lighting is passing light source parameters manually to the shader in vao-s? Or ...
- 313
5
votes
1
answer
249
views
How to rasterize a line when the background color is not always white?
I've to rasterize a line taking into account not only the background color of the screen, which is white, but also the color of other objects in the scene. In my case, I've just another object, a ...
user4718
1
vote
3
answers
526
views
How are the colors for each pixel from a Ray Tracer stored in an Image?
I have begun learning how to create a Ray Tracer and 1 thing I am confused about is how the pixel color from a Ray Tracer is stored into an image. Do we use SetPixel...
- 2,473
4
votes
1
answer
295
views
Material Layering
So after reading this Unreal Engine 4 Documentation page: https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/LayeredMaterials/
(Which describes how to use material layering in UE4)
...
- 2,473
3
votes
1
answer
575
views
Flexible Vertex Format Constants in Direct3D 11
How do you migrate Flexible Vertex Format Constants (or FVF codes) from DirectX 9 to Direct3D 11?
Old code:
...
- 1,044
5
votes
2
answers
144
views
Problem with Basic Diffuse Lighting
So recently I have been learning how to implement Diffuse Lighting in DirectX and I have done so with the following code:
...
- 2,473
3
votes
1
answer
543
views
Creating a gently moving 2D fog effect
I am trying to create a fog-like effect, similar to that found using perlin noise. I know where I can find information about that effect, but it's harder for me to tell if it's an efficient route for ...
- 193
1
vote
1
answer
787
views
How to use Shaders with vertex & index buffers?
I'm trying to render a randomly generated terrain with vertex buffers and OpenGL. I want to use a shader to color the terrain, but it seemms like my shader isn't used. I have used shaders before when ...
- 57
7
votes
1
answer
362
views
Ray casting in fan configuration produces point cloud with curvature, how to eliminate curvature?
I'm attempting to perform an intersection test using ray casting (not sure if correct term so please forgive me if not) and am outputting the intersections as a point cloud, and the point cloud shows ...
- 173
4
votes
1
answer
2k
views
Compute shader not updating buffer, or vertex buffer unable to read the updates
I'm learning OpenGL compute shaders and following this guy's code, and I have stuff drawing, but not updating. The particles are spread out in their starting positions, but they stay there.
...
- 161
7
votes
1
answer
210
views
Proper architecture for rendering history of streamed data (points)
Overview
My program receives some data points (0-400 per sec).
...
- 307
3
votes
1
answer
299
views
Can't make blending work
I have a 3 dimensional dataset where each value of the dataset is normalized to [0, 1]. I want to visualize this dataset by using texture, and blending.
However, it ...
- 263
2
votes
1
answer
181
views
Uniform not set, despite valid location
I try to write a simple triangle mesh renderer with OpenGL.
...
- 1,800
4
votes
2
answers
1k
views
How to check which API's are available on a given machine?
I'm building an engine, which has Vulkan for its primary rendering engine. But to have at least some backwards compatibility with devices that don't have drivers for it (mainly mobile) I want to ...
- 43
6
votes
1
answer
723
views
Perspective correct interpolation of normal values
I'm currently writing a software rasterizer and I'm at the point where I can draw arbitrary triangles with vertex colors and perspective correct texture mapping. I do point and directional lighting by ...
- 95
6
votes
2
answers
770
views
Open GL Shader Storage Buffer Objects to replace Vertex Attributes
At first: I already posted this on the stackoverflow community. I'm new and didn't know about this community here. I apologize.
I basically got the same question as the guy who asked here: https://...
7
votes
1
answer
1k
views
Resulting Probabilty Density in Path Tracer for paths using Next Event Estimation
I am trying to implement my own Gradient Domain Path Tracer by following the code of this guy who already implemented it:
https://gist.github.com/BachiLi/4f5c6e5a4fef5773dab1
I already managed to ...
- 355
8
votes
1
answer
2k
views
Role of PDF of Uniform Random Sampling in a path tracer
I am trying to implement my own path tracer but before arriving to the question I want to give you a short overview:
In the implementation of the rendering equation I use some particular technique in ...
- 355
2
votes
1
answer
367
views
Generate this kind of 2d burst or pulse algorithm?
I'm currently trying to develop a game using Cocos2d-x using C++.
I really need to generate this burst or (donut-shaped) pulse.
I'm having a difficult time how to generate such shape.
At first, I was ...
- 31
4
votes
0
answers
1k
views
Represent vector with arrow
Another code review question.
I am trying to draw an arrow to represent a vector. I have started with an unit arrow with vertices defined as follows:
...
- 263
3
votes
1
answer
694
views
Ray-tracing the Cornell Box results in really inconsistent image
So I have a vector of glm::vec3 containing the triangles for the classic Cornell Box called triangles. The Draw method casts a ray for each pixel on the screen and ...
- 33
6
votes
1
answer
1k
views
How to compensate low amount of rays reaching the light in a Path Tracer
I am trying to implement for research purposes a path tracer, but so far but results are not so good and I will explain you why. The general idea before getting to the code:
I am working on paths ...
- 355
5
votes
2
answers
756
views
Path tracer not rendering shadows
I am trying to implement for research purposes a gradient-domain path tracer. In order to achieve this step I first need a working Path tracer. I have been creating one so far but results are wrong ...
- 355
2
votes
1
answer
1k
views
OpenGL C++ Camera Rotation Problem
Currently for a university assignment I have been given a 3D rendering engine, capable of rendering a 3D world. One task is to create a first person camera for it (I know with OpenGL you don't have a ...
- 23
2
votes
1
answer
3k
views
Creating vector shapes using only C++ [closed]
I've been researching for quite a while and I couldn't find any explanation or at least a how to create a vector graphic application (specifically in windows) where I can create a 3D vector shape, say ...
- 21
2
votes
0
answers
211
views
Free 3D Scene Simulation Framework [closed]
I want to visualize a scene with simple shapes (e.g. boxes, pyramides, etc.) and I am looking for a tool or framework in C/C++ to do this. Focus of the application is to parameterize the relative ...
- 21
21
votes
1
answer
21k
views
Get vector length with GLM
I am quite confused over how GLM library is behaving or I am using it improperly.
glm::vec2 testVec(6,-4);
float len = testVec.length();
I get the value ...
- 1,209
7
votes
2
answers
2k
views
OpenGL with SFML, create an n-pointed star?
Completely stuck on how to do this. Yes, it is a homework problem, but its the first we've had in the class so not too familiar with graphics. Also, seeing as its homework, please don't just give the ...
- 71
6
votes
1
answer
1k
views
Type conversion to GL-types
If I have a std::vector<Foo> and want to store its size in a GLuint, my compiler gives a warning that there is possible ...
- 1,800
1
vote
0
answers
119
views
Selecting pixels within a circle having a decimal (non integer) radius
I want to select a pixel within a circle of a certain radius. But the radius is expressed in a decimal form (0.12). What does it mean to have a radius equal to 0.12? And concretely how to pick a pixel ...
- 141
6
votes
1
answer
171
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 ...
- 163
5
votes
1
answer
261
views
How to set the GLFW OpenGL target?
I'm programming on a Mac and I'm learning OpenGL in the library GLFW.
My problem is that my Mac supports OpenGL up to version 4.1, but when I try to compile the shaders with ...
4
votes
1
answer
816
views
Angle between two points in Cartesian coordinate system C++
I'm trying to rotate a rectangle so that it faces another rectangle in a spiral.
Im using the Bullet pyhics library and freeglut for the 3d application, for anyone interested https://github.com/...
- 303
9
votes
2
answers
8k
views
Archimedean spiral in C++
Im trying to plot the x and y positions of an Archimedean spiral in C++.
So far I've been trying something like this, but no luck:
...
- 303
8
votes
1
answer
1k
views
The meaning of early ray termination and front-to-back traversal in ray tracing
I'm new to computer graphics. These days I've been trying to understand how ray tracing using an acceleration data structure works. I came across the term "early ray termination" several times, I ...
- 141
5
votes
1
answer
2k
views
Draw angles lines in raster graphics using bresenham line algorithm
I at the moment trying to draw some angled lines using bresenham line algorithm which can circulate a 2d array of size 21x21, as a line angled from 0 - 2pi.
So the idea is that the program has to ...
- 183
3
votes
0
answers
65
views
Draw lines angled from 0 to 2 pi in a raster grid [duplicate]
I am trying to draw an angled line in a raster grid.
The idea is to create a function that given a start point, a length and an angle, would give me the pixel positions that combined would give me a ...
- 31
5
votes
1
answer
1k
views
Ray-triangle intersection algorithm not intersecting (C++)
I've been trying to implement the Moller-Trumbore ray-triangle intersection algorithm in my raytracing code. The code is supposed to read in a mesh and light sources, fire off rays from the light ...
- 51
7
votes
1
answer
6k
views
Shadow rays in Raytracing
After spending a few days making very little headway with a simple Raytracing program that implements Phong illumination (with shadows and no attenuation), I'm convinced I've made a logic error that I'...
- 73
8
votes
1
answer
862
views
DirectX12 CbvHeap
With directX12 they introduced heap descriptors. A way for us to describe the table for resources we wanted to send to the shaders. I'm admittedly very new at computer graphics and only tinkered a bit ...
- 828
4
votes
1
answer
5k
views
DirectX 12 Constant Buffer Binding
I can't really seem to figure out how to bind two constant buffers to my shaders. I have them described like so. One in slot b0 and the other in slot b1.
...
- 828
14
votes
4
answers
1k
views
Projected grid water horizon detail
I'm trying to implement an ocean scene with C++ and DirectX11. Currently I have a projected grid, Gerstner waves and a basic shading. My problem is that when I aim my camera horizontally, so I can see ...
- 143
3
votes
1
answer
205
views
First quad being re-used?
I had posted about this issue in a previous question, however, I thought instancing was causing it, whereas even using normal uniforms or a SSBO (which's what I'm using right now) causes it, which ...
- 91
5
votes
0
answers
352
views
Incorrect instanced rendering
Previously, to render a bunch of quads, I was simply using a few uniforms (one for a model matrix and another for the texture layer ID). However, I'd rather not have to loop through each quad and set ...
- 91
5
votes
1
answer
975
views
Dx12 Vertex Buffer incorrect
I'm playing around with directX 12 and I'm having some problems loading geometry in. I have a std::vector vertices definition and I do exactly what the dx12 template does with it.
...
- 828
7
votes
1
answer
2k
views
How to convert a thread ID into Screen Space Coord in an OpenGL Compute Shader?
I've written an implementation of the sphere tracing algorithm in OpenGL 4+.
As an experiment/toy project, I'm re-implementing it using the OpenGL 4.3 compute shader, but I'm having trouble with the ...
- 398