# All Questions

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12 views

### Can someone explain why raytracing isn't able to make Global Illumination?

I've watched a few videos about raytracing vs pathtracing, and one thing that consistently pops up is the idea that pathtracing seems to be able to do global illumination, whilst raytracing is not. ...
7 views

### Passing variable through cbuffer vs. shader input in HLSL

Let's say I want to pass some kind of value to a pixel shader in HLSL. I can either make a cbuffer and pass the value directly to the pixel shader, or I can make a cbuffer in the vertex shader and ...
29 views

### Character Creation. Cartoon look, Eyes and Extra Parts. What advantages are the combining to one mesh?

I am fairly new to CG and 3d art. I'm trying to learn to make good game assets (ie. Low poly count, clean looking) in a cartoon style. I'm making this character as pictured. But his eye is a separate ...
18 views

### Help me improve my CG skills. Making Cartoon game assets for Unity. Having a 'style' that matches throughout the game [closed]

I've been working on lots of game ideas (I am trying to do all coding AND graphics alone). I really want my games to have a distinctive look to them but I am struggling, all my games end up looking ...
606 views

### Fundamental drawbacks of rasterization over ray tracing

Are there any fundamental drawbacks/limitations of rasterization as compared to ray-tracing? When I search on the internet, I get vague explanations like rasterization does not provide lighting ...
16 views

### Dealing with selection of spline/bezier curves in graphical software

In 2d and 3d environment we can select primitives like lines and polygons by performing point/ray intersection test with the respective primitive. However how does one approach the selection of ...
32 views

### How compute new camera parameters given a velocity vector?

My goal is to update camera parameters given a velocity vector so that the camera points in the direction of the velocity vector. How should one compute the update matrix for the camera parameters?
27 views

### how to change the near clipping plane of a perspective projection matrix for OpenGL

I am trying to only change the near clipping plane of a given perspective projection matrix for OpenGL. My problem is, that the near clipping plane is way too close, and the far clipping plane is very ...
30 views

### Raytracing, divide by PDF neutralized the effect of D and G terms, what is the problem?

Following some documents on internet, I divide my ray tracing result by PDF. Then it seem the D and G terms disappeared. Only F term is still visible, it looks like Fresnel only. ...
18 views

### Convert point clouds into voxels

I have points that are obtained by sampling a mesh(which is not watertight). Now, I would like to convert that mesh into voxel? Does anyone have any suggestions for solving this problem?
12 views

### Find a plane clipping a mesh with max intersection area/volume ratio [closed]

This is a cross-post from StackOverflow. I am looking for an algorithm to fit a plane based on the local convexity of a mesh. The mesh is very roughly elliptical cylinder-like, one side is flatter, ...
56 views

### Ray tracing Bug with Diffuse material

I am trying to do ray tracing in python (following the tutorial given in Ray Tracing in a weekend). Basically I am shooting rays from eye and the recursively bounce around, each time they hit ...
19 views

### OpenGL Per-Object Outlining issues

I'm trying to draw onlines around the objects, the outlines for any object should be see though very other object, I've successfully been able to draw the outline but the pixels get discarded in the ...
46 views

### What's the word for “how noticeable a particular part or pixel of an image is to a human”?

I remember hearing about an algorithm to calculate some property of each pixel of an image which represents how noticeable that pixel is to a human, and so how likely they are to notice if that pixel ...
31 views

### Order Independent Transparency: How to approach sorting

In an "Order Independent Transparency" implementation, one faces sorting a large amount of (as many as the number of pixels in the viewport) sets of data with relatively small number of ...
46 views

### In alpha premultiplied sRGB a color component can't be greater than the alpha, right?

Afaik, in alpha premultiplied color the components stored so: [r * a, g * a, b * a, a] So the fully opaque white color is: ...
28 views

### Is spectral response curve and spectral power distribution the same thing?

I'm reading section 5.2 of pbrt 3rd edition and came across the part where they explain the concept of RGB colors. When we display an RGB color on a display, the spectrum that is actually displayed ...
20 views

### DirectX FVF(Flexible Vertex Format ) equivalent in OpenGL/Vulkan?

Is there any directX FVF(Flexible Vertex Format ) equivalent in OpenGL/Vulkan.
62 views

### How to find the importance sampling function for a specified BRDF?

I am currently working on BRDF and their associated probability density functions (PDF) in order to importance-sample them. It is really hard for me to find the correct way to compute the PDF of a ...
44 views

### Catmull–Clark issue with plane corners

I implemented catmul clark based on this Wikipedia article. And it seems to work fine for meshes where the edge point count is equal to the face point count, but not for planes where the corners have ...
18 views

### Determining camera pose from symmetrical points?

I'm trying to do some 3D reconstruction from photographs and "the usual (SfM) suspects" don't seem to be working out. (Also, while I have a pretty good grasp of the basics of Linear Algebra, ...
49 views

### Why do materials have both an ambient color and a diffuse color?

One of the first things I learned about computer graphics lighting (and light in general) is that when a ray of light hits a surface, the surface absorbs certain colors and the light retains the rest. ...
22 views

### Writing perspective transformation matrix for x=0?

I see the discussion at this link, but I still get confused and I think my question is rather a simple one. If I assume the center of projection as p = (1,0,0), how can I write the 4x4 projection ...
19 views

### List all faces of a mesh visible from the view of the camera Opengl

as the question suggests I have to identify all the faces that are visible from the camera's view and do some processing with them. I have a single mesh. I am thinking of giving individual faces a ...
108 views

### glBlitFramebuffer does not copy all textures

The setup I have a working bloom shader implemented which creates a fbo with two textures attached to it. The first texture holds the entire scene The other only displays objects which are supposed ...
35 views

### How does a Vertex Buffer manage memory?

I'm learning OpenGL and I'm trying to understand things properly. If my understanding is incorrect at any point, please correct me. Introduction So let's say we have a triangle. This triangle has its ...
38 views

### A solution to sprite visibility in a raycasting engine with variable wall heights?

I am writing a raycasting engine. At this point, I have added sprites, and I am using a z-buffer, with one stored length to a wall for the x coordinate of each ray. Below is an image of a sprite which ...
26 views

### MSAA performance with forward shading

I have done some tests in OpenGL with multisampling, by specifying a multisample buffer as the default framebuffer. I used forward shading for rendering. From what I've observed the more primitives I ...
27 views

### Metal API clips all primitives?

I am trying to port my simple app from D3D12 to Metal and I am stuck at rendering a simple triangle. The window does not show any primitives; only the clear color is visible. Debugging my application, ...
36 views

### What are Gbuffers?

Good Morning! I am in need of help to understand GBuffers. What exactly are they? and how can I access them through unity? Is it something I need to create? Or does the engine create automatically? In ...
38 views

### gl_ClipDistance vs gl_CullDistance

Why are there very similar yet distinct arrays: gl_ClipDistance[] vs gl_CullDistance[]? What would be some use cases where the ...
44 views

### Fake cubic Hermite spline interpolation with smoothstep

When scaling an image with Bicubic Interpolation, the Cubic Hermite spline interpolation is used. smoothstep is one of the four basis/blend functions of this kind ...
140 views

### What is this graphical effect called?

I was watching this trailer: https://www.youtube.com/watch?v=pWh5388AEHw and at 1:22, the player used a magic trick that created a sphere that warped the projection of the scene. Does anyone know ...
167 views

### Why is the symbol for solid angle a small omega in the definition of the BRDF?

In many resources the BRDF is defined like $$f_{r}(\omega_{i},\omega_{r}) = \frac{\mathrm{d}L_{r}(\omega_{r})}{L_{i}(\omega_{i})\,\cos{\theta_{i}}\,\mathrm{d}\omega_{i}}.$$ The index $r$ might be ...
34 views

### Bottom up (as opposed to top down) text on projective geometric algebra?

I have been reading the SIGGRAPH course notes on projective geometric Algebra, and I get some of what's going on. However a lot of the knowledge needed to understand these PGA notes seems to be based ...
47 views

### Why there's no z-fighting for coincident planes if the camera look perpendicular at them?

There's a similar question Why do identical polygons not z-fight in OpenGL? but I believe I have a different setup. As can be seen in the picture the vertices for the planes are different and on the ...
31 views

### Is there a Performance Penalty for LOD objects with different topology?

I have a fairly complex-shaped object I've modeled, and in creating the LOD meshes, I've merged some verts, deleted some and even added some after in cases where this manipulation produced an n-gon. ...
53 views

### Embree: Performance issue when ray casting User Defined Geometry

I am working on the integration of Intel's Embree library into our home renderer to accelerate its rendering time. Our renderer supports various geometry types, such as quads, triangles, but also ...
27 views

### How to add spectral texture to an object? (Mitsuba renderer)

Summary I'm looking for a possibility to use spectral texture data in Mitsuba renderer. The texture is saved as a tiff image stack and is to be added to the surface of an arbitrary object. Software ...
39 views

### Way to estimate the amount of overlap between a rectangular prism and a frustum?

I am looking for some way to estimate the amount of overlap between a rectangular prism(not axis aligned) and a frustum. The rectangular prism is probably always going to be larger than the frustum ...
85 views

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### Camera calibration focal lengths and pixel sensitive area relation

In camera calibration (i.e. camera calibration with OpenCV) does result for focal lengths fx and fy depend on the photo-sensitive area inside the pixel ? For example, a camera sensor (CCD/CMOS) with a ...
73 views

### Ray tracing geometries with same position, translation and scale

this is my first post on the Computer Graphics Stackexchange forum. Apologies in advance if I am doing something wrong. I have the problem that I have a scene with overlapping geometries. To be more ...
60 views

### how to put a pixel somewhere in a window(directx)

I'm interested in direct3d game programming and I'm just a beginner. I'm familiar with the Win32 API and i was wondering... how to put a certain pixel somewhere in the window is there like a function ...
53 views

### What are the limitations and benefits of anti-aliasing and subpixel rendering respectively?

Just like the question, I am wondering are there any limitations and benefits for these two techniques?
104 views

### Why do Nvidia and AMD have to update their drivers for game releases?

I like to know the technical aspects of it. Game developers use APIs like OpenGL or DirectX. The functions provided by these APIs, I would assume, work flawlessly with all graphic cards because they ...
109 views

### Ray casting and rasterization 101

Recently I've became an intern in company-name and my internship task is(for now) create rasterization using rays. I'm mostly interested in pure math, so basic ...
19 views

### DO states carry forward between Draw calls?

If I am setting Fast Clear related state for Draw Call 1 then does it carry forward to the following draw calls as well? Follow up question- how about between different batch buffers? "Working in ...