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53 views

Simple Two Point Perspective of a Cube

I know this question may be a little basic, but still I haven't found an answer for it anywhere. Let's say I have a normalized cube; vertices at (+-0.5, +-0.5, +-0.5) If I render it on screen (...
0
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1answer
138 views

Monte Carlo Importance Sampling

I am following the "Ray Tracing - the Rest of your Life" book by Peter Shirley and I am facing some troubles in the implementation of Monte Carlo importance sampling, and Direct light sampling. Monte ...
-1
votes
1answer
89 views

Where should I learn shaders as a vulkan user?

I have no prior experience with any other graphics low level libraries and I have barely any clue how shaders work, any book related to shadings is bloated with opengl code and is demoralizing.
1
vote
1answer
51 views

Is `groupshared` memory stored in L2 cache of GPU?

The article says that L1 cache is shared by work items in the same work group(aka. SM) and L2 cache is shared by different work groups. In Direct3D, it seems that a thread group (which is specified ...
0
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1answer
117 views

How to simulate a line laser diode?

I'm interested in simulating the way a laser line deforms when it strikes an object and runs along the surface of it. Which concepts would be involved? Is there any 3D modeling software out there that ...
1
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1answer
105 views

ShadowMap peter-panning and wrong direction

I am creating Forward-Rendering DX11 engine and I have some troubles with shadow-mapping algorithm as it doesn't work as supposed. As you can see - shadow is peter-panning and looks totally not ...
2
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0answers
88 views

How to model braids?

Many hair simulations render their hair as lines (usually splines). Since hair is a really thin object. if the hair is braided, rather than having thin infinitesimally small cylinders, you have ...
2
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0answers
69 views

Trying to optimize texture mapping

We are developing a PPI plot for a radar system, similar to the following: NOTE: 1 radial is defined as a single slice of data within the circle, and 1 range gate is defined as a single point along a ...
2
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0answers
33 views

Mantiuk's contrast mapping seems to amount to a gamma correction

I'm reading this paper and one thing sticks out at me. Let's say I use the approximate transducer: R = 54.09288 ·G^0.41850 Then I scale it: ...
1
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0answers
183 views

GGX BRDF is greater than 1?

I am implementing a GGX BRDF, this is the formula I used is from:https://schuttejoe.github.io/post/ggximportancesamplingpart1/ And this is my implementation: ...
-1
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2answers
111 views

What is a list of common, cheap, real time rendering algorithms?

I am well aware of the existence of Blinn-Phong shading, which is a great tool when you are doing, for example, modelling algorithms and wan't to focus on the model. In this case a full BRDF result, ...
0
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1answer
101 views

How Image Based Lighting is applied to indoor scene?

Now the mainstream engine's approach is to use image-based lighting to achieve approximate global illumination, but such a technique seems to be only applicable to outdoor scenes.What kind of ...
1
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0answers
69 views

Convey screenspace bounding box of rendering result

Imagine I render to an FBO some arbitrary geometry. Geometry can be rendered via single or multiple draw calls. For the sake of the question, assume I know nothing about geometry or transformation ...
1
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1answer
110 views

Why can I see the diffuse lighting effect on a perfect mirror?

Currently I am learning PBR by Unity3D. I find that even I turn the smoothness to 1, I can still see the diffuse lighting effect, which does not make any sense to me. Imagine I trace a ray from my ...
5
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0answers
114 views

Why is Forward Rendering/Shading named this way?

Forward rendering is the 'classic' approach to the rendering pipeline. Nowadays it is mostly replaced by a more flexible, deferred rendering approach. I did some research and had trouble finding ...
2
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0answers
55 views

Show the edges between the clipping plane and clipped objects [closed]

I want to utilize shaders to not only discard fragments if they are on one side of a predefined plane but also render a contour along the intersection. My fragment shader currently does something ...
2
votes
0answers
65 views

Constraining a Polyline to Look Smooth

What are the mathematical constraints required for a polyline, i.e., a piecewise linear curve, to appear as a smooth curve to human vision? I've discovered one document that specifies only that the ...
3
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1answer
79 views

Tiled Image Palettization Algorithm?

In most cases today, image palettization consists of reducing the overall number of colors in an image to some fixed number globally. This is typically solved as a straightforward but computationally ...
-2
votes
1answer
119 views

This function syntax is confusing me

gladLoadGLLoader((GLADloadproc)glfwGetProcAddress) I have never seen this syntax before. Presumably glfGetProcAddres is a function, but it has the brackets behind it. Is this only possible in open gl ...
1
vote
1answer
89 views

Are texture binds expensive?

I am trying to get a feel for how much effort I should put into this. I am building a basic 2D engine and for my use case there are only 8 textures. Each draw call in this engine currently requires ...
3
votes
1answer
197 views

Which method for detecting edges of white object on white background?

I would like to segment picture of cloths in order to remove the background. The pictures come from online retailers, they usually have an homogeneous white background. Using Canny edge detector ...
0
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0answers
89 views

Path tracing - Better images without Gamma correction?

So I read about tonemapping and Gamma Correction recently and have implemented it in my path tracer. For the time being I'm using Reinhard tonemapping operator as described in his paper $L_d = L_w *...
0
votes
1answer
84 views

Ray tracing the next week: understanding Instances

My question is not about the code, but it's about the approach used by the author Peter Shirley (and apparently common practice in ray tracers) of handling Instances. To understand the question it's ...
1
vote
1answer
127 views

Why do animated CG characters always feel fake?

Why do animated CG characters always feel fake? Usually if a CG character is an animal (or humanoid creature), they tend too look kinda off. Their movement tends to look oddly smooth or lightweight, ...
0
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2answers
62 views

How to create 2D (directional) noise?

I'm just getting started trying to understand noise generation algorithms. What I'm trying to achieve is to get a 2D (or 3D) grid of random directional vectors (again, 2D or 3D) according to a noise ...
2
votes
1answer
54 views

Is it possible to bind dynamic texture samplers to a shader in DX12?

So usually texture samplers are set directly in the D3D12_ROOT_SIGNATURE_DESC structure in DX12, at least that's how I've been setting them. I was wondering if it's ...
0
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1answer
95 views

Weirdly looking diffuse irradiance map

I have problem with creating diffuse irradiance map. As reference I am using https://learnopengl.com/PBR/IBL/Diffuse-irradiance and https://github.com/TheEvilBanana/PhysicallyBasedRendering/blob/...
1
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0answers
59 views

Why don't discretization errors occur with compute-shaded kernel filters?

An efficient compute-shaded image filter would be emitted with (screenX / [kernel width], screenY / [kernel height], 1) groups and one kernel in each group, allowing texels to pass into groupshared ...
1
vote
1answer
107 views

How can I control memory for command allocators and command queues in D3D12?

The D3D12 programming guide suggests specific allocation strategies for command queues and allocators, but the creation methods for those objects operate directly on queue/allocator pointers without ...
0
votes
1answer
149 views

Ray tracing in One weeked: issue with metal reflection

Problem I am following the book Ray tracing in one weekend , and I got stuck after the implementation of the material Metal. I checked my code many times, and it looks exactly like the code ...
1
vote
1answer
119 views

GBuffer: Framebuffer with different texture format types?

I rely on this answer from Nathan Reed: How much precision do I need in my G-Buffer? It is proposed to use two different texture formats for one Gbuffer. However as far as I know, color texture ...
3
votes
0answers
139 views

How to implement explicit light sampling when implementing path tracing?

I implemented a path tracer and got a similar result like this one. Sample: 4096, time used: 537.05s The algorithm is exactly the same as the one in wikipedia, where only the Gathering Path is ...
1
vote
1answer
88 views

OpenGL Unable to retrieve the values of data sent to shader using textures

I've been following these tutorials and i can't figure out how to send data to shaders using textures. https://en.wikibooks.org/wiki/OpenGL_Programming/Scientific_OpenGL_Tutorial_02 In this tutorial ...
5
votes
1answer
151 views

Blur with alpha transparency

I'm writing a simple box blur for a graphics library. The formula makes the average of a range of pixels by adding the ARGB amounts and then dividing by the blur range For example, with a blur range ...
0
votes
2answers
338 views

How do I use texture coordinates of a .obj file in OpenGL?

I have an obj file, with texture coordinates (indicated by vt). How would I use this to load textures in OpenGL?
0
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2answers
95 views

An algorithms for covering a 2d polygon with a predetermined number of rectangles?

I am looking for an algorithm that is able to cover with non-overlapping rectangles in a pre-defined number and minimum area a generic 2d-polygon. Polygons are usually free-hand draws, so they can be ...
4
votes
0answers
87 views

How to use Photometric Units with Rendering Equation?

So I was just reading up on how to create more Physically Based Lights and wandered into the realm of photometry. I read the paper "Moving FrostBite to PBR" and in it the author claims he decided to ...
0
votes
2answers
101 views

transformation from cartesian coordinates to spherical coordinates without calculations

Given this graph in the 3d cartesian coordinates i should figure out the spherical coordinates representation but without the use of calculations . I've been trying to solve this the whole day but i ...
0
votes
2answers
129 views

How to set equivalent PDFs for cosine-weighted and uniform-sampled hemispheres?

I'm trying to add BRDFs to a very basic path tracer. Starting out, I'd like to convert just the Lambertian material, with two different sampling methods, to ensure that everything is working right. ...
0
votes
2answers
67 views

Using transformations to get from A to B image

I try to solve this, First, I used scaling: $Scale(S_x,S_y)=S(\sqrt 5,\sqrt 5)$ So, I enlarge the bottom of the house and the sides, to the same size of B image. Later, I used rotation: $R(\theta)=...
0
votes
1answer
29 views

Can you generate your own HDRI maps without using photos?

For example, preparing a scene in Maya using standard lights and rendering out a panorama? Could they also be made from scratch in photoshop using 32bit color? Is there a reason why people don’t ...
2
votes
1answer
100 views

What is the oldest hardware able to feasibly support Vulkan?

What is the oldest hardware or minimum requirements conceptually able to support a fully hardware-accelerated Vulkan implementation? I am not referring to what implementations are currently available ...
1
vote
1answer
31 views

Consistent animation speed across systems

I recently noticed that in all games, no matter what system you play on or what specs you have, your character will always move at the same speed even if there is no frame rate limit. I was wondering ...
0
votes
1answer
39 views

Define position and orientation in a local coordinate system

Suppose we have a world coordinate system W and a 3D model m1 defined in W. ...
0
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2answers
163 views

How to convert from Object space into World space (exercise from 3D Math Primer book)

This is not homework. I'm self studying Computer Graphics, using the book "3D Math Primer for Graphics and Game Development" (2nd edition). So there is the exercise 6 in chapter 3 which I can't figure ...
2
votes
3answers
135 views

Strange stripes on the gradient

On the picture below you can see mathematically perfect smooth transition from black to white. But I noticed that on all gradient picture I see strange strips and the color transition doesn't feel ...
0
votes
1answer
77 views

Skybox is rendered on the model instead of surroundings

I'm trying to implement Skybox in DirectX 11 (DirectXTK) but when I'm rendering skybox, then texture is rendered to my sphere model instead of showing skybox outside. Rendering code: ...
4
votes
1answer
402 views

Anisotropic GGX BRDF implementation. How is it related to isotropic GGX BRDF?

Introduction I am implementing anisotropic GGX BRDF and have encountered strange behaviour of my implementation. I thought that if I compare the microfacet distribution function I have with the one ...
2
votes
1answer
58 views

Should animations be locked to FPS or Fixed time

I have been working on a 3D engine and I am now implementing animations, but I can't find out whether or not to use the FPS of the engine or a fixed time method for the transformation's speed. Could ...
3
votes
1answer
84 views

Adding noise to gradient

I found this picture When you zoom in to any part of the image, the background looks a bit noisy/grainy. See pixels around "violent violet" label: I'm trying to understand how to achieve the same ...

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