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1answer
40 views

Sensor size of Sony HDR-HC7e

I want to motion track a shot from my Sony HDR-HC7e camcorder and I am not quite sure about the horizontal sensor size(width). I set the focal length to minimum and the recording to HDV 16:9 This ...
1
vote
2answers
53 views

Discrete Gradient?

I am trying to understand how to get the discrete gradient of a mesh that is being used as the input of some function $f$. In other words for every vertex $v$ there is a scalar quantity $s$ associated ...
2
votes
1answer
22 views

Sort half-edges around common vertex in 3d

I'm trying to figure out this problem for very long time and am no getting nowhere. I'm working on a simple 3d modeler that uses half-edge data structure. Say I have non-manifold geometry where two ...
0
votes
0answers
19 views

Ear-clipping algorithm for non-planar polygons

I was looking into the ear-clipping algorithm for triangulating simple polygons. I have successfully implemented it on planar polygons. However if polygon is non-planar the algorithm breaks down. ...
1
vote
1answer
36 views

Path tracing - cannot converge diffuse sampling + oversaturation

I'm in process of creating progressive path tracer using DX12 + DXR. I managed to create working raytracing code + pathtracing code with multiple bounces but I'm experiencing problems stated below (...
0
votes
1answer
376 views

Translate an arcball camera upwards or left-right

This problem is giving me a really hard time. I'm always looking at the origin and have a camera that moves around it in an arcball mode. That part works beautifully: I'm calculating the camera ...
0
votes
1answer
109 views

What is wrong with my metalic PBR shader?

I feel like my light conservation math isn't correct, but I am not sure which part is wrong. Is reflected light supposed to influence the diffuse light? Does metalness only affect the reflected ...
4
votes
3answers
101 views

Visualize the interpolated unit quaternion on the surface of the unit sphere

My major is mechanical, please forgive me for asking questions that may seem trivial to you. First, I'm reading the following paper: Dam, Erik B., Martin Koch, and Martin Lillholm. Quaternions, ...
3
votes
0answers
33 views

Why does my image has a square pattern in cuda path tracer?

I am writting a path tracer in cuda following the Shirley's book. I am having a square pattern as an output. The size of the block change if I change the block dimensions. For this image, the block ...
1
vote
1answer
67 views

Export Model Textures Per Face

(Note that as far as attempts go, I can't find anything that helps me) I have a 3D polygon, and for simplicity's sake it's going to be the one below: It is textured using the UV map below: Side ...
2
votes
1answer
28 views

Blend Shape, Pose Blend Shape, and Shape Blend Shape

Since there is a lot of cross-section between computer vision and computer graphics for 3D pose and shape estimation of non-rigid objects, I would like to know what "blend shape", "pose ...
0
votes
1answer
408 views

sdl2: Compiler throws “Undefined Reference”

I'm trying to learn computer graphics, but when I tried to get this very simple windower running with c ...
2
votes
3answers
59 views

How to paint onto 3d models

I have searched this topic for very long time and have found basically no information on it. If we have a 3d model with a uv layout. What is the basic technique for 3d painting on said model with a ...
2
votes
4answers
147 views

3D object to slices like in medical scan

I am novice lacking professional terminology. I want to create from 3D object (let's say from polygon mesh) a slice through to PNG file in order to create something like reverse medical MRI scan from ...
0
votes
2answers
51 views

Shear(?) matrix projection along Z (depth) axis

I'm creating a primarily 2d game (platformer perspective) with 2d background parallax layers. The parallax effect falls out of the fact that I'm positioning a bunch of layers in 3d and using a ...
1
vote
1answer
19 views

Improve accuracy of mesh gradient?

So to make it simple. I currently use a method I found online to compute the gradient of a scalar field of a mesh. To test how accurate this is, I made a sphere and followed the gradient direction of ...
9
votes
4answers
6k views

What does GPU assembly look like?

I have played around with CPU assembly programming like Nasm, Tasm or Masm, but I'm really curious to know how GPU works now. However, i'm quite confused when I look on internet. I've heard about Cuda ...
2
votes
2answers
157 views
+50

OpenGL - Recreate position in viewspace from depth values

Current state: I belive the reconstructed positions are correct. However, I still have the same problem as all the time. When I rotate around my single pointlight appears to be moving around also. I ...
1
vote
1answer
41 views

Worsening sampling quality of raytracing with increasing distance from world origin

I am using RT shader (DXR) to generate g-buffers with code below. There was no problems with smaller scene (pink room from cwyman tutorial - http://cwyman.org/code/dxrTutors/tutors/Tutor5/tutorial05....
0
votes
1answer
53 views

Realistic chainmail reflections for videogames

If I were to create a chainmail that has realistic reflections, where would I start learning about what mechanisms to use? Normal cloth seems too simple, and the reflections look bad (they have to be ...
0
votes
1answer
35 views

Albedo image map to color's Light Reflectance Value (LRV)

In many datasets in the literature of both Computer Vision and Computer Graphics there is the albedo map of a scene represented as RGB images, which in principle corresponds to the diffuse reflecting ...
1
vote
1answer
91 views

Weird glColor3f results in framebuffer objects

The code is glColor3f(1, 1, 1); gluSphere(gluq, 0.2, 10, 10); glColor3f(1, 0, 0); glTranslatef(1, 0, 0); gluSphere(gluq, 0.2, 10, 10); In short, when I draw ...
0
votes
0answers
21 views

Finding a flat plane within iPhone depth data

I have real time depth data coming from an iPhone and I want to identify flat objects within the point cloud so that I can highlight the Hard edges in the images. The objects can be at any angle and I'...
1
vote
0answers
44 views

How can i understand the algorithm wu line?

I have Wu's line algorithm but I don't understand all the lines of code very well. ...
2
votes
1answer
44 views

Path Integral Form with Path Tracing

The description is going to be long and detailed, thanks in advance for your patience! I am learning the path integral form of light transport equation(LTE) to be able to follow recent rendering ...
3
votes
1answer
34 views

Mis understanding of the Heat Method

I have been trying to understand a paper in CG for a while, called the Heat Method by Ken Many things have clicked but I don't fully understand it yet. In particular. In the following $u$ is a vector ...
1
vote
0answers
33 views

What is the simplest way to create basic 3d/isometric style images programatically like autocad/blender

I need the simplest route to programatically, via command line, through python or node, to create something like this using basic input of distance and 90 degree turn etc: https://i.imgur.com/SdY02gQ....
1
vote
1answer
23 views

Real 3D interior room from 360 images

If I have 360 images of an interior room from all different angles, would it be possible with current 3D software technology to create a real 3D representation of that room, where the camera could ...
2
votes
1answer
102 views

How can I raycast with chunks?

I am attempting to implement chunks/octrees to speed up my render times. However, sometimes the walls show horizontal or vertical lines (rays hitting the inside of voxels?) or some blocks disappear ...
2
votes
2answers
43 views

Using array of textures in DX12

I managed to create code, working correctly as Texture2DArray in hlsl by using single ID3D12Resource and binding it as D3D12_SRV_DIMENSION_TEXTURE2DARRAY with constant array size. ...
0
votes
0answers
53 views

Calculating of vectors in Phong Lighting Model

I'm learning about computer graphics and I have some questions about calculation of the vectors, so I will write the exercises that I have and I hope that someone can help me with the formulas that I ...
3
votes
1answer
28 views

Algorithm for constructing doubly connected edge list in 3d

This post explains how to construct double connected edge list in 2d. One of the steps in the algorithm is to sort the halfedges around a vertex in clockwise order. However this will not work in 3d. ...
0
votes
1answer
41 views

Reference for Inverse Rendering

I'm not sure this is the right place to ask for this reference but it's worth the shot since it is graphics related. I'm looking for the very first paper describing what "Inverse Rendering" -...
2
votes
3answers
60 views

How to Sample 3D Points Outside and Inside the Mesh Surface

I have a mesh of an object enclosed in unit volume cube and I would like to sample points inside and outside the mesh surface. What are the different ways of doing it? Is there any sample code ...
2
votes
0answers
44 views

How does the texture file should look like?

I am wondering why the texture of the following 3D model https://app.ignitionrobotics.org/GoogleResearch/fuel/models/Transformers_Age_of_Extinction_Mega_1Step_Bumblebee_Figure Looks like the ...
5
votes
1answer
57 views

What should I do when a new sampled direction is below a normal oriented hemisphere?

I generate random directions from the pdf of D term in GGX BRDF. On the picture, white dots are new directions and the cross is the light direction, with roughness = 1. What should I do with the ...
4
votes
1answer
45 views

Gradient descent (Not ML) on arbitrary meshes

So I am doing a gradient descent like algorithm on the surface of a mesh and I just noticed something: The above is the geodesic gradient (the distance to a single vertex) Look at where the ear ...
1
vote
0answers
28 views

Why Screen Space effects flicker?

Nowadays is less of an issue, i think SS got massaged a little bit, but you can still spot it. These happen with SS Reflections, SSAO and Bloom. When you move the camera, the effect starts to flciker ...
2
votes
2answers
119 views

Latency difference between texture copy on GPU vs CPU?

Does anyone happen to know the latency difference between copying a texture on cpu (using, say, memcpy) compared to gpu (using, say, ...
2
votes
0answers
27 views

Global root signature crash

I have a problem with RTPSO creation. Using local root signatures for each of rgs (ray generation shader), chs (closest hit), miss is working correctly. However, for performance sake, I want to use ...
4
votes
2answers
49 views

How to decide which way to triangulate a quad?

Apologies if this is a dumb question... but given four arbitrary (non-coplanar) points in 3D space, there are obviously two different ways to triangulate the quad that they form. One triangulation may ...
1
vote
0answers
87 views

How can I pull up the whole area of the square? [closed]

What algorithm can i use to pull entere area? i have this image: are there many algorithms, which algorithm can you recommended me to implement? Edit 1: my square was builded with lines (bresenham), ...
2
votes
1answer
45 views

Compute the interpolation factor between the SLERP of 2 quaternions, given those quaternions and the SLERP result

I am looking for a way to calculate the value of t of quaternion SLERP by having three quaternions. Forward direction: ...
2
votes
1answer
96 views

Smart half edge iteration?

In my HE implementation, half edges are stored in an array. When I iterate over the edges, I color all the HE black, and when I do an operation on an edge (e.g edge splitting) I mark both the current ...
2
votes
0answers
71 views

BVH works fine, but why does it slow down a lot when using Cornell Box? How to improve it?

I am using the SAH-BVH from PBRT-v3, it works fine for triangle-mesh, especially for dense mesh. But here is a problem. If I added Cornell box while building the BVH tree, the BVH performance will ...
2
votes
1answer
84 views

How to work around the pointer limitations of GLSL?

(I am new to Computer Graphics in general) I am learning how to ray trace from a book called ''Peter Shirley - Ray Tracing in One Weekend''. In the book, the code is written in C++. I have ...
16
votes
5answers
14k views

Why are quads used in filmmaking and triangle in gaming?

In film school, in the classes of 3D modeling, I was told that when we model something for films we maintain topology of 4 edged polygons. Any polygon which has more or less than 4 edge/vertex is ...
0
votes
2answers
83 views

Ray Tracing, why does the GGX make my rendering result darker and darker for each frame?

I am trying to add GGX and PBR textures to my GPU ray tracer. The result is very strange, it's getting darker for each frame. ...
2
votes
0answers
32 views

multiple Quaternion slerp inverse to calculate relative coordinates

I am creating a 3D spherical curved display (only a part of a sphere). The camera usually is inside of this sphere. This display has texture coordinates. The image below shows the display with its ...
1
vote
0answers
59 views

How can i stretch a line?

How can I remodel a line, i want to draw first a line then i want to remodel the line such as in paint software, which algorithm should I use? Are there several algorithms to achieve this? i am using ...

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