Questions tagged [raytracing]
Questions specific to raytracing (as opposed to scanline rendering), the 3D graphics technique of intersecting rays from the camera with objects in the scene.
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Mathematical Foundations of Radiative Transfer
I'm new to learning about ray tracing, but have been fairly confused by the mathematical foundations of it all. Specifically of radiometry/radiative transfer. I've internet searched a lot and skimmed ...
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How many years till photorealistic games? [closed]
I just saw this post by NVIDIA:
RTX Global Illumination
The images shown seem to be rendered in realtime which got me thinking about when games will achieve full photorealism and become ...
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Create a virtual server which use the full power of my GPU
i dont know if i can create a virtual server (with vmware, virtual box or with something like that), and if i can use the full power of my graph (i have a nvidia rtx 2080 super) or if I'm going to ...
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GL_OUT_OF_MEMORY Error when glDispatchCompute takes longer
I built a simple Ray Tracer which takes use of OpenGL's Compute Shader and traces ".obj" Files.
The results are passed to the Host-Program via glMapBufferRange after finishing computing.
...
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Ray tracing where illumination itself affects the geometry
I am interested in a scientific application in which ray tracing is necessary, but also where the light itself alters the geometry of the surface mesh (imagine perhaps that the beams of light have ...
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Why is the image from the CUDA version not as sharp as the CPU version?
I am extending Roger Allen's Ray Tracing in One Weekend in CUDA (and also here) by following Peter Shirley's Ray Tracing: The Next Week; specifically Image Texture Mapping.
The image I obtain from ...
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BVH uses aabb for a sphere in Ray Tracing: The Next Week
While studying Peter Shirley's Ray Tracing:The Next Week, I came across an issue that I cannot quite figure out:
Stepping through the random_scene() case of the ...
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Debugging refraction in a sphere
I have been working on recreating some of the scenes from Peter Shirley's raytracing books using compute shaders and the new Metal raytracing API. It is going well but I am having some trouble with ...
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How do we know if a ray intersected a triangle in one in a million
I've taken a class about ray-plane intersection on this: https://www.khanacademy.org/computing/pixar/rendering/rendering-2/v/rendering-5
Suppose we shoot a ray at the scene and this scene contains ...
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Pathtracing - many bounces reduce shadows
I'm creating DXR PathTracer highly influence by Matt Pettineo's one - https://github.com/TheRealMJP/DXRPathTracer ; Relevant HLSL code below:
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Importance sampling GGX NDF - fireflies and bright final result
https://schuttejoe.github.io/post/ggximportancesamplingpart1/ - I have problem implementing this method. Somebody asked question about this before ( Can't understand the Importance sampling GGX ) ...
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Deriving radiance from irradiance and intensity
I'm reading PBRT and am stuck in chapter 5.4 about radiometry. In particular:
We define the irradiance as the average density flux arriving at a surface with units $\frac{W}{m^2}$. So for a point ...
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Importance sampling a cosine distribution
Let's take a look at this blog article - https://schuttejoe.github.io/post/ggximportancesamplingpart1/ and image presented as a result of implementing it:
Inside above link, you can see description ...
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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 ...
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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 (...
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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....
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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 ...
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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 ...
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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 ...
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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.
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Raytracer help - Background color writing over some colors?
I'm implementing Peter Shirley's "Raytracer in a Weekend: The next week" and I'm having some trouble with rendering a scene with a light. I'm not sure if the issue is the background color or ...
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Hit group - export already defined
I am getting this error when creating RTPSO with multiple hit groups:
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Euclideon Unlimited Details Voxel Engine Architecture
As I understand Euclideon haven't just rendered voxels for these infamous demos, since the amount of geometry is still too large for the 2010 PC with software raytracer and the model taking whole HDD ...
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Texture value clamped to 1
I am working on ray/path-tracer using DXR and I'm starting with simple AO. In first pass, I am storing normal value and RayTCurrent():
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Is BVH faster than the octree/kd-tree for raytracing the objects on a GPU?
Apparently most people use BVHs in their raytracers. The ray-AABB intersection code is very fast and and the BVHs also compresses empty space efficiently, working even with infinitely large objects, ...
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Why is eye-based ray tracing preferred over light-based ray tracing?
It seems that virtually all path tracers use eye-based or view-based path tracing. That is, the light rays originate from the camera rather than the light source. The reason given for this everywhere ...
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What's a good research topic in Computer Graphics?
I am currently trying to find topics for my master's thesis. I would really like to do something in the field of computer graphics, but I've been having trouble finding what are some current problems ...
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Rendering moist/wet materials like human anatomies for surgical simulators
Real human anatomies look wet/ moist when operated. I am looking for some good methods for rendering anatomies in a virtual simulation, and hence I have done a literature survey on 'Rendering wet ...
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Math for adaptive supersampling for raytracing
How do I determine how many (jittered) rays to trace for a given pixel, as a function of the statistics of a small initial set of test rays? Also, what size should the initial set be? (it's currently ...
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Implementing monte carlo path traced refractions problem
I am writing a forward monte carlo path tracer with the added feature of specular refractions for transparent materials, I have managed to come this far but something is not quite right and I am ...
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Ray Tracing Bounding Volume Hierarchies nodes
I'm new to computer graphics programming so I apologize in advance if my question is stupid.
I'm trying to implement a BVH for my ray tracer and I looked at some lectures explaining BVH. They all ...
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Weird patch on reflective spheres on planes in raytracer
I am writing a small raytracer in python , everything was working fine but when i implemented plane geometry then the reflective spheres are getting weird patches on lower bottom. image below:
I ...
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Prove radiance contributions of deeper paths fade away
When ray tracing, I find it intuitively clear that deeper paths have a lower contribution to the overal picture than shorter paths. This is the main reason why it is generally okay to render a picture ...
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a very simple raytracer is giving a black output which is implemented in python
I am trying to implement a simple raytracer in python. I am following this tutorial here
here is my code, i have explained in comments the relevant parts .All i am getting is a blank image.
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Understanding of Microfacet monte-carlo path tracing
I am trying to implement BRDF microfacet path tracing and I think I need a little push.
I will explain what I understand so that you can correct my mistakes.
I start with simple rendering equation:
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Feeding acceleration structure to the GPU then raytracing it in a compute shader?
I want to use Vulkan's rasterization to solve for the visibility problem, but once that is done I want to do shading, reflection and transmission through a raytracer which also runs on the GPU. With a ...
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Visualize the variance of an image
Let $h_j$ denote the image reconstruction filter of pixel $j$.
I'm estimating the color value $$I_j=\int h_jf\:{\rm d}\mu$$ of the $j$th pixel (see [Veach, Section 8.2]) by an asymptotically ...
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How do I produce a metallic surface in ray tracing?
I can't manage to produce a metallic looking sphere despite trying many things. I have the basics working, i.e shadows, refraction etc. but I'm not sure what combination of these will allow me to ...
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How to handle negative reflection directions in raytracing?
I got a function that generates samples from a GGX visible normal distribution function. When I use it to calculate reflection directions obviously some of these intersect with the surface agin (...
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Considering a path generated by bidirectional path tracing under a different strategy
Say I have constructed a path, using bidirectional path tracing (BDPT), consisting of a light subpath $y$ with $s=2$ vertices and a camera subpath $z$ with $t=3$ camera vertices.
Now I want to ...
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How is the image reconstruction filter on the path space defined in terms of the filter on the raster space?
Say we have a image reconstruction filter $h:R\to\mathbb R$ defined on the raster space $[0,w]\times[0,h]$, where $w,h\in\mathbb N$ define the width and height of the image plane in pixels, ...
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Relation between camera sensor responsivity and image reconstruction filter associated with a pixel
Let $W_{\text e}$ denote the camera sensor responsivity (i.e. importance) and $h_j$ and $W_{\text e}^{(j)}$ denote the image reconstruction filter and sensor response associated with the $j$th pixel, ...
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Properties of the image reconstruction filter in rendering
Let $f$ denote the measurement contribution function for paths of length $k\in\mathbb N$, i.e. $$f(x)=g(x_0\leftrightarrow x_1)W_{\text e}(x_1\to x_0)t_k(x_0,\ldots,x_k)L_{\text e}(x_k\to x_{k-1}),$$ ...
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Scaling of the final image in Metropolis Light Transport
I don't understand why the PBR implementation of Metorpolis Light Transport scales the final image by b / mutationsPerPixel.
The authors write:
Each Metropolis ...
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Determining shortest vector between a ray and an axis-aligned 3D bounding box (correcting a near-miss)
I have a situation where (due to floating point error) a ray that is known to hit a bounding box fails due to floating point error. (1e-8 or so)
Expanding the box is not an acceptable solution in my ...
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Quantify the variance of pixel measurements
Say $E_j$ is an estimator of the value $$I_j=\int f_j\:{\rm d}\lambda$$ of the $j$th pixel given by the path space integral of the corresponding measurement contribution function $f_j$. $f_j$ is of ...
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Is casting a shadow ray non-symmetric in pbrt?
According to the description in the book, Scene::IntersectP() "checks for the existence of intersections along the [passed] ray". This operatorion should be ...
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Which technique should be used for rendering under water images, Ray tracing or Radiosity?
Rendering is the process of computing a three-dimensional geometric description of a scene into a two-dimensional image representation that looks real. Ray-tracing and Radiosity are two of the most ...
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Need a fast ray-box intersection that handles if a ray is parallel and in line with a plane of the box
I've seen lots of spins on the ray-box intersection test, and a lot of them seem to boil down to this code: (omitting some details here)
...
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Reading thesis on cone tracing, did the author make a mistake?
I am reading this document that talks about signed distance field rendering.
In that document section 6.3, on the topic of cone tracing, it says:
Cone tracing is an extension of the sphere tracing ...
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