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1answer
29 views

How can I get a signed distance (SDF) from a mesh?

I am trying to use constructive solid geometry (CSG) and boolean operators to combine various shapes and get the outer (possibly concave) hull. This seems to work okay when using primitive shapes like ...
0
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0answers
12 views

OPENGL NURBS in VBA

I'm coding OPENGL with Excel VBA I'm using arkham46 package which is really great: Découvrez la 3D OpenGL 1.1 en VB6/VBA | arkham46.developpez.com I'm not able to display NURBS surfaces, only NURBS ...
1
vote
0answers
12 views

Using the HTML canvas and colors to track objects

I need to rewrite a short utility library, to get it working with the Brave browser (My actual question isn't about brave per se.) canvas-color-tracker - example of it being used and src/index.js is ...
0
votes
0answers
17 views

Quadric Edge Collapse Decimation of an object for reducing number of its vertices damages the original shape of object

I have been using "Simplification: Quadric Edge Collapse Decimation" for simplifying my meshes to only have ~800 vertices and it has been working with a couple of meshes I tried. However, ...
1
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0answers
8 views

How to extrude a face from a selected mesh in Babylon,js using the ExtrudeShape method?

I'm trying to extrude a face from a selected mesh in Babylon.js using the ExtrudeShape but can't figure out why I got flipped faces. The bottom extrusions always comes flipped for a reason I ignore. ...
1
vote
1answer
24 views

Environment map importance sampling (beginner)

beginner here. I am implementing importance sampling for environment maps in Scotty3D, a CMU CS project (but I am not a student). The task can be found here I have a problem with the sample's pdf, it ...
0
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1answer
27 views

Computing heat diffusion creates weird results

I am trying to model heat diffusion on the surface of a mesh. I annexed the most important bits of theory about this topic as screenshots on the question see the bottom. The crux of the issue is we ...
1
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0answers
24 views

Questions about caculate the highlight direction from spherical harmonics functions

Recently I‘m working on a Precomputed GI Project I'm trying to use a technique called AHD, Amibent Highlight Direction, rendering my project; I use Unity and my target platform is Android. First: ...
0
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0answers
38 views

UV coordinates calculation broken

I've tried using the classic formula of calculating barycentric coordinates. When the plane on which you are projecting the texture is collinear to any of the base vectors it crashes with a division ...
0
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1answer
44 views

How's this laser cutting effect with backlight achieved?

Sorry for the general question, I don't even know how to tag it: https://www.youtube.com/watch?v=61UkkpsASwQ In this video, the effect is such as if there were a laser cutting a shape with a light ...
0
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0answers
22 views

What's a compeling use case for geodesic distance in a real world CG application

I'd like to find a concrete example of how geodesic distance can be useful in CG such as games or the movie industry. (An example I like for mean curvature is when it's used to fake ambient occlusion. ...
0
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1answer
48 views

Fastest Simulation Of Mass Spring Systems

I'd like to simulate a 4-dimensional cloth in the web browser, since browsers don't offer great ressources for numerical computation, I'd like to know which algorithm uses the least amount of ...
0
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0answers
13 views

Data from staging Texture2D incorrect (DirectX 11)

I'm trying to implement 3D picking in my engine. To do this I am rendering objects with different colours and getting the pixel at certain mouse position and extracting the colour value from a special ...
0
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1answer
44 views

Scale Sampled Depth Value

I am currently porting the atmosphere algorithm used by the UE4 engine to my engine. As the original algorithm from Bruneton is in Kilometers i had to adapt it to my engine which uses meters. ...
0
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0answers
34 views

Combining two images based on their depth maps

Lets assume, we have two depth maps with us and their corresponding color maps. Now, our task is to populate a final image that will be displayed. Each pixel in the final image needs to be calculated ...
0
votes
1answer
25 views

Filling pixels under or above some function

Seems like a simple problem, but I just cant wrap my head around it. I have a config file in which I declare a few functions. It looks like this: ...
0
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0answers
28 views

Unity path tracing makes the pc crash

Good Morning. I'm testing Path Tracing techniques with unity, following this tutorial. http://three-eyed-games.com/2019/03/18/gpu-path-tracing-in-unity-part-3/ But I'm in trouble. Whenever I try to ...
0
votes
1answer
45 views

What is this vertical line contour effect in glitch art called?

Some underlying portrait above is glazed over with a series of vertical lines that neatly follow the contours of the face. What is this effect called and how can it be replicated, step-by-step, in ...
0
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0answers
18 views

How to draw a pdb 3d structure in webgl?

I am trying to create a 3d structure in webgl using 3d coordinates from a pdb file mentioned below: https://www.rcsb.org/structure/1RE2 I don't know which one is the appropriate one, so i used gl....
0
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1answer
29 views

Animated rainbow distortion wave effect

https://foundation.app/mg/20210227-3lau-makes-history-1790 The link above shows a video animation that has a rainbow wave distortion effect applied to it, that ripples across the video. how, and in ...
3
votes
1answer
51 views

Binding vs bindless

I was trying to understand what exactly is 'binding'. I found an answer on quora on this. From this, binding basically sounds like sending data from to GPU with help from CPU. I got to know more about ...
2
votes
2answers
65 views

PBR : Understanding the right part of Split sum integration of specular IBL

This is the website I am learning from. In the specular part of IBL this is the split sum approximation Now the left part of the equation I have asked in This post and I have understood everything ...
0
votes
2answers
44 views

What is the name of this moving color pixels effect, for animating a painting?

https://superrare.co/artwork-v2/spring-22267 The artwork in the link seems to be based on a painting of a woman, but effects have been added that assign a pixel to each block of the painting that ...
1
vote
0answers
21 views

Understanding rig joint angle definitions in Blender

I am trying to transfer some mocap data from one skeleton to another one. However, the skeletons have different rest poses (one has T-pose, and the other some other one), so I am trying to convert the ...
0
votes
1answer
44 views

rendering a triangle has no color

I wrote a program to render a simple triangle with colors, the triangle is there but there's no color. ...
1
vote
1answer
58 views

Objects in depth buffer are always black (0.0)

My problem is exactly what titles and screenshot below says - rendered object depth value is 0.0 in depth buffer. I'm using DirectX 12. Matrices: ...
1
vote
1answer
45 views

getting the outline of an arbitrary set of shape unions

I hope this is the right forum to ask this question. I want to experiment with procedurally generating some buildings, and as a first step I want to generate a 2D shape to use as a foundation for the ...
1
vote
2answers
74 views

What does the z-buffer look like in memory?

I am an amateur game developer, and I've been reading a lot on how computer graphics rendering works lately. I was reading on the Z-buffer recently and I can't quite seem to be able to wrap my head ...
-1
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0answers
15 views

OpenGL: Error glVertexAttribDivisor not found

The function glVertexAttribDivisor when used with CMake - it just throws the following error during compilation, which means that function is not imported. ...
0
votes
0answers
38 views

Building a higher-res detailed image from a video

I'd like to know if the following technology already exists, and if not, how feasible it would be to create something like this: I came up with an idea for creating a higher-res image that is put ...
0
votes
0answers
18 views

Finding the “face number” of a mesh in obj format in MeshLab or other visualization tools by clicking on it

I am interested in clicking on different faces of an object mesh (loaded as in obj format) in MeshLab (or other obj file visualization tools) and understand what is the face number? For example if my ...
0
votes
1answer
25 views

How can I bind my texture in the correct orientation?

I have successfully completed a working program that draw a rotating sphere with a map of the world as the texture, simulating the earth in space. However, the texture is bound on it's side, i.e. all ...
0
votes
0answers
14 views

Translate the camera with Pan gesture (when it is rotated )

I am new here I am not good in math SO what I need is I need to translate the 3D camera with Pan gesture on 2d Screen With below code it is working But if camera has some Euler Angle (rotated ) then I ...
1
vote
3answers
116 views

Question about function for color

I would like a help to understand the following line of code: return float3(pow(color.r, 2.2), pow(color.g, 2.2), pow(color.b, 2.2)); I've seen some places calling ...
0
votes
1answer
92 views

Given two 3d vectors, find the rotation matrix between the two

So I am making a raytracer following the very helpful online book of Gabriel Gambetta but I stumble on the rotation matrix part. My linear algebra background is 3Blue1Brown video series "The ...
1
vote
2answers
72 views

How does OBJ format determine vertex normals?

I have a very simple obj file: ...
2
votes
2answers
103 views

What is exactly the third component in homogeneous coordinate system?

I was reading the wiki article about homogeneous coordinates , I learned that it has it's advantages when it comes to performing affine transformation, since you can represent it only matrices. But I ...
0
votes
1answer
54 views

Half-Edge Data Structure with holes

I am trying to implement next/prev of edges in half-edge data structure. But I ran into this question. If there are two holes with a common vertex, will the closed loop of the edges run as in the ...
0
votes
2answers
97 views

How to calculate vertex normals on a mesh with non-planar polygons

If I have a mesh consisting of polygons that are not necessarily triangles and not necessarily planar. As answered in the previous question I asked, there's no correct answer to calculating normals ...
1
vote
1answer
64 views

Why do 3d modeling packages use a single normal per polygon and how is this viable for smooth shading

If we have a quad that is non-planar. Why do most 3d modeling packages choose to use a single normal for the quad (Specifically for Blender3d by using cross product of two edge's vectors that do not ...
0
votes
1answer
44 views

OpenGL blending with the screen

I don't understand how OpenGL performs the blending of a texture on the screen. By default, the clear color is set to (0, 0, 0, 0). If we use the default blending equation GL_SRC_ALPHA and ...
2
votes
1answer
177 views

Performance difference in Opengl compute shader vs Vulkan Compute Shader vs Cuda/opencl and others

I have been told their is no performance difference if you are skilled enough when it comes to gpu computing . And cuda only performs better because nvidia wants it to. I have also read graphic api's ...
2
votes
1answer
32 views

Reading neighbouring pixels during object draw call

I need something to be cleared up for me, and I hope this is the right place to ask my question: I intend to attempt stochastic transparency, where I will draw glass panes and smoke particles onto the ...
1
vote
2answers
44 views

Is there an efficient way to achieve color blending in compute shaders?

What I want is a function like imageStore, but instead of replacing a value - applying a blend operation to it, e.g. addition. It is not possible to do something ...
1
vote
1answer
21 views

Mat4 that is written to a storage buffer in a compute shader has an altered value when read back

I am attempting to use a compute shader to calculate joint transforms for animations. I use a loop to calculate the global joint transforms from the local transforms. Relevant code below: ...
2
votes
0answers
78 views

Do all microfacet brdf models diverge at grazing angle?

My question follows directly this one. Reading the famous paper of Walter, it comes that the plotted curves of figure 13 (in question in the related topic) are not directly the brdf but rather the ...
2
votes
1answer
28 views

results of Curved PN-Triangles algorithm has visible edges

I implemented the curved PN triangles algorithm described in this paper to smooth geometry in real time. After the implementation was finished (in glsl) I realized, that this algorithm smooth the ...
0
votes
1answer
48 views

My OpenGL program is not drawing filled polygons

I'm trying to learn OpenGL in c++ (I used it in Java) but I have a problem, I make a triangle, but it doesn't draw on GL_FILL and in GL_LINE it just draw a line, I can't find my mistake, I guess my ...
3
votes
1answer
32 views

Plotting pbrt-v3 Gaussian filter

I want to plot the Gaussian filter of pbrt-v4 with a radius $(100,100)$ and a standard deviation ($\sigma$) of $0.5$. I would expect something like this: When I plot the pbrt-v4 Gaussian filter with ...
0
votes
2answers
85 views

Does Vulkan have the equivalent of OpenGL's separable shader program and pipeline?

If you have a shader pipeline in OpenGL that goes something like the following: ...

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