# All Questions

3,964 questions
Filter by
Sorted by
Tagged with
90 views

### Parametric equation for Catenary curve between two Points

I have two points in 3D space, A and B. I need to have a parametric equation of the catenary curve such that: Cat(0) = A, Cat(1) = B, Cat(t)= f(t, A, B) How can I derive the function f
64 views

### Why can't I get fog on OpenGL?

I am creating a cylinder, and there is fog around it. I can't handle two things: the inner surface of the cylinder, realized as a smaller diameter cylinder, actually gives me just a second cylinder ...
60 views

### What is this method of interpolation / blending?

I am reverse-engineering two classes from a game. The two classes are responsible for generating sets of t values for interpolating / blending between two points through the formula: ...
108 views

### Can dxf Files Represent a Parametric Design?

dxf files emerge from various applications, for example Autocad, LibreCAD and so on. Sometimes a design should be flexible, e.g. one should be able to change one dimension of it and keep everything ...
1 vote
102 views

### Why do texture samplers seem to bleed into other instances when rendering multiple instances of the same mesh with differing textures

I originally asked this question on the gamdev stack exchange but was told by a friend I would be better served here. Original Question So I will start off by laying out the relevant structure of my ...
1 vote
186 views

### DDS BC7 Thumbnails on Windows 10

Is it possible to enable accurate thumbnail previews for DDS files that use the newer DX10 headers (DirectX 10 headers)? It seems there is very limited information about this. I did find a couple ...
• 111
110 views

### drawing ellipse with rotation cause inaccurate result

i'am a junior in computer graphics , currently i learn how to draw ellipses with rotation . when i preform rotation with 90deg or 180deg nothing unusual happened , but when i try to rotate with any ...
• 23
1 vote
138 views

### Is there a canonical way to convert G1 continuity to C1 continuity for splines

I understand what C1 and G1 continuity are (e.g. this is not Continuity of parametric and geometric continuity). But let's say I have a list of cubic splines that are, together, G1 continuous. Is ...
92 views

### What vergence angle is commonly used for "infinitely far away" objects in stereoscopic displays?

I think that VR / AR experts will know the answer to this. At what vergence angle are "infinitely far away" objects such as star field textures drawn in head-mounted VR / AR displays ? I ...
• 163
1 vote
56 views

### LOD/culling algorithms with procedural meshes

I am experimenting with procedural meshes. Those are generated at runtime in a compute shader. I'm getting to the point where those geometries are big enough to require some sort of culling/LODing ...
• 161
139 views

### Whats the best way to render (2D) parametric curves with uniform stroke width?

I want to create a rendering engine that mostly renders parametric curves on a 2d screen. As far as it seems, todays graphics are all dependent on vertices and matrices, so not sure where to start or ...
18 views

### How does denoising factor into most render engines + practical question

I'm a student working on an experimental animation. The animation has been selected to be screened at a festival, but they would like a resolution that is beyond what my single graphics card can ...
1 vote
33 views

### How to encode UTF inside an Encapsulated PostScript

Twenty years ago I made a descriptive illustration program whose output was the industrial standard Encapsulated PostScript, which is also compatible with the LaTeX system. In order to write accented ...
115 views

### How to properly use the BRDF from glTF 2.0 specification in path tracing while using metallic/roughness materials?

I've built a renderer which should render glTF materials, as they are defined in their specification. So I should be able to render satisfying (similar to Cycles and Ospray) results just from the base ...
1 vote
64 views

### Unknown array of floating point numbers. View matrix?

I want to control the camera in an old game using head tracking (TrackIR, opentrack, etc.), such control was not provided by the game engine. I'm trying to find the camera coordinates and rotation ...
• 13
45 views

### Optimal Command Ordering for CPU/GPU concurrency

I am writing a renderer that uses a deferred clustered shading technique. On the CPU I group lights, decals, and environment maps into 3 seperate clustered structures (functionally, arrays of unsigned ...
• 21
1 vote
191 views

### Having trouble rendering entire sphere

I'm working on a program where I need to draw spheres. The method I'm using is creating an octahedron And using tessellation shaders to subdivide it into a sphere, however there is a patch of the ...
• 11
1 vote
26 views

### How to get back project point cloud from rendered rgbd images by rgbd?

Given a sequence of RGB-D images rendered by blender and the camera parameters for the blender camera(Perspective Projection camera). How can I back project the RGB images with depth map to a RGB ...
• 11
1 vote
53 views

### Term confusion about volume scattering

We have two different terms, for example, let's talk about scattering only. Scattering coefficient Scattering cross-section These two terms are supposed to have different physical meaning. I read it ...
• 575
1 vote
40 views

### how to fix this strange effect when editing image?

G'day, I have this strange effect when editing my image. It seems to happen a lot on photos with the sky in it, but in the CR2 file it doesn't show, only when i open it in the software i am using does ...
1 vote
57 views

### Normal Map Under rotation Issue

I have been trying to apply normal maps to a rotating sphere with light shining directing from above the sphere (0,1,0). but lighting does not look correct under rotation as one side of the sphere ...
116 views

### Creating a UV Map for a 3D Cone

I have the following problem I am currently facing. I am creating the vertices for a cone based on the number of segments and the radius of the base and top. This is done as follows: ...
• 167
70 views

### OpenGL get default depthbuffer

I have an application that uses only the default opengl framebuffer. It is initialized with color and depth buffer. I want to use the depth buffer as a uniform within a shader to access the current ...
• 1,136
13 views

### What is the color space of Luminosity blend mode and other three blend modes that photoshop use , HSB HSL or LCH

Here is what I have tried: I create a base layer and a blend layer and I choose Luminosity blend mode, so the result suppose to have the hue and Saturation of the blend layer and the Luminosity of the ...
139 views

### want bokeh blur with custom shapes

I have a 2d texture and a shape matte, the matte could be any shape, like a star, heart, and so on, and I want to use this matte to generate different-shaped bokeh blur, how can I do it? and normally, ...
1 vote
58 views

### How does changes in vertex data work?

I have been learning computer graphics and for some time and can't seem to wrap my head around one concept. How to handle vertex data changes? Ex. 1. I have a text rendering on a screen. And up on ...
82 views

### I need to implement a CPU Rasterizer but am unsure how to parallelize rasterization

I have a rendering engine that has CPU path tracing support, as well as GPU (Vulkan) rasterization and path tracing support. It uses a rasterization pre-processing step to identify the resolution of ...
• 215
87 views

### Ray light color at distance

I am obviously not understanding something related to light for a ray tracer. Reading Spectral representation and Point light calculation A bit of a context: My question is: in room at X degrees ...
• 23
277 views

### How does Unreal Engine 5's Lumen (most likely) implement reflections?

In this YouTube video, the creator mentions that reflections in Unreal Engine 5's Lumen "work by tracing the path of light as it bounces off of surfaces in the game world." Does this mean ...
• 159
33 views

### Optimized 3D rendering using dots and/or line segments of different sizes in Scratch

I'm developing a 3D rendering engine in Scratch, which is a block-based visual programming language. It does not have any support for bitmap rendering, but there is a "pen" plugin that lets ...
62 views

### Converting ACES ap0 color space into srgb?

I'd like to know the correct when of converting ACES AP0 color space into sRGB. Let's say artists decide to pick colors outside of sRGB in AP0, will ACES handle this situation correctly, meaning no ...
132 views

### Rendering light balls: Where to do perspective calculations?

After rewatching Bisqwit's starfield renderer video, I've decided to try to rewrite the program in order to learn more about compute shaders and shader programming in general. My knowledge at this ...
• 109
138 views

### undefined reference to SDL_setRenderDrawColor'

I am getting C:\Users\rasmu\AppData\Local\Temp\ccwOn3mM.o:main.c:(.text+0x11f): undefined reference to SDL_setRenderDrawColor' C:\Users\rasmu\AppData\Local\Temp\ccwOn3mM.o:main.c:(.text+0x155): ...
51 views

### Fresnel and light reflection/refraction

I keep reading about fresnel and there is one thing I don't fully understand. My understanding : Here is my understanding so far, so please correct me where I am wrong. Fresnel is related to ior (eta)...
• 23
106 views

### Do GL compute shaders trigger TDR if they crash. Not just timeout?

I'm getting a TDR trigger after 4ms with a GL4.3 compute shader. tdrDelay is currently set to 30 secs, this obviously isn't long enough to get a timeout with the default Windows 11 tdrDelay value let ...
• 411
57 views

### Facetted look when using SampleBias

I am writing a simple material system for a game. Each material can have a specular value (phong) that is translated into "smoothness" via environment map. Similar to PBR, I compute a ...
• 171
1 vote
94 views

### How to compute discrete partial derivatives in 3D

I'm supposed to compute partial derivatives for 3D volume rendering (in ray tracing). I'm bad at math and so I can't understand what $f$ is in my case. In reviewing examples, I'm seeing the $f$ ...
• 111
1 vote
45 views

### How to display real time 3-D orthogonal vector rotations?

I'm an embedded developer here with very little experience in computer graphics. I'm currently working on a GUI that can display a calculated inertial solution at run time. I have hardware that can ...
68 views

### OpenGL 3.0 is not supported by the OpenGL driver - RizomUV

I have a problem with RizomUV 2022.0. When the program starts, it comes up with pop-up "OpenGL 3.0 is not supported by the OpenGL driver", so I can't import any geometry and work. I'm ...
25 views

### What happens when we select lower resolutions on a high-resolution monitor?

I have a monitor with a resolution of 1360x768 (16:9), When I set the resolution to 1280x768 (5:3), 1024x768 (4:3), 800x600 (4:3), even 1920x1080 (16:9) it completely covers the screen and the monitor ...
64 views

### How does one construct a 3D file format from pixels and vertices? [closed]

I have searched around in a lot of places but I have yet to find some place that explains 3D file formats in a way that aligns with the model I have right now. I have a simple problem (I think) but it'...
• 99
1 vote
149 views

### How to get the boundary of delaunay triangulation

I'm implementing tunnel detection algorithm in the paper "Computing Geometry-aware Handle and Tunnel Loops in 3D Models". Before the actual tunnel detection, the input needs to be ...
• 31
60 views

### Non Uniform Scaling vs Shear in Image Transformation

I am reading computer graphics. I am unable to distinguish between Non-uniform Scaling and Shear. Can someone explain the difference with two different examples?
• 121
294 views

### Raytracing in OpenGL or Vulkan?

I was looking at this glass ball rendering with an image inside of it (zoom out to see the glass ball), and noticed that it looks like they simulate the refraction of light as it crosses from inside ...
• 159
1 vote
41 views

### replace IBL with single color - the lighting equation

I want to avoid IBL (image based lighting), however my scenes are way too dark - especially close-to-mirror like surfaces, which get little contributions from other direct light sources in the scene. ...
• 41
22 views

### models used for verifying standard PBR shaders

I know this collection of models: https://casual-effects.com/data/ I am looking for something similar, but with models with standard PBR materials (roughness + metallic). I want to verify that my ...
• 41
1 vote
357 views

### Which coding strategies exist to handle opengl texture size limit?

I recently hit the roof for maximum texture size for my opengl implementation (GL_MAX_TEXTURE_SIZE contains $3379$) when I wanted to create a texture for a 4k resolution video frame ($3840 \times 2160$...
• 125
59 views

### Does OpenGL allocate on glBegin/glEnd?

You can enclose arbitrary amount of vertices within glBegin/glEnd statements. Does OpenGL limit the number of vertices you create or it allocates memory for more?
73 views

### Why an object becomes larger when drawn in perspective

I am following David Salomon's book "Transformations and Projections in Computer Graphics" where it is explained how to project a 3d object to the 2d canvas in perspective: Define a point ...
• 103