Questions tagged [vulkan]
For questions about the Vulkan graphics/compute API.
108
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Path tracer -- How to debug erroneous behaviour?
Edit: I've pinpointed the problem. If I change:
local_colour *= (rayPayload.color.r*mask.r + rayPayload.color.g*mask.g + rayPayload.color.b*mask.b);
into
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How are strings for debugPrintfEXT handled in glsl?
Glsl does not support string / char data types, but obviously debugPrintfEXT works and takes some form of string. How are these handled in glsl?
Ideally I would ...
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Can Vulkan Queue Families be separate but identical?
I was trying to find examples of GPUs with more than 3 queue families to see what edge cases programmatic selection of compute and transfer queues might encounter.
This card has six. Two of the extra ...
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Is it possible to read arbitrary data at arbitrary array offset in glsl?
TL;DR
In a Vulkan / GLSL program, I have several shader files, all accessing the same material buffer of arbitrary data. All materials have an arbitrary layout, e.g. one might be a float, one might ...
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187
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Vulkan backward-only path tracer with caustics
TL;DR -- who has discovered, in the past, a backward-only path tracer that generates caustics not needing extra convergence of any kind? I'm collecting similar algorithms, in order to fully understand ...
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Vulkan Syscalls
I'm working on educating myself more about computer graphics, and the more I learn and play with the technology, the more I get frustrated by the dependencies on C++ (even though I know why it exists)....
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Vulkan: Compressed image formats and mipmapping
I am currently grappling with the computation of mipmaps for block compressed formats (BC7) in Vulkan. The limitation with these formats is that the size of the block compressed texture needs to be a ...
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36
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How to set Vulkan Validation Layer filter via the vk_layer_settings.txt?
I have just activated the Vulkan Best Practices Validation and due to that I get the following warning:
Validation Layer(WARNING): Validation Warning: [ UNASSIGNED-BestPractices-vkCreateInstance-...
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151
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Relative coordinates -- cumulative sum
I have a vertex shader happily producing all the vertices I want for a 2D plot. Now I want to also render a plot of the same data, but each point relative to the previous one, like SVG Paths using <...
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Does WebGPU Have Significant Feature/Functionality Gaps As Compared to Vulkan/DirectX12/Metal?
A friend and I are considering using webgpu native (more specifically C++ bindings) for a project. We were wondering, since WebGPU likely runs on top of Vulkan XOR DirectX12 XOR Metal at any given ...
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85
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Why do texture samplers seem to bleed into other instances when rendering multiple instances of the same mesh with differing textures
I originally asked this question on the gamdev stack exchange but was told by a friend I would be better served here.
Original Question
So I will start off by laying out the relevant structure of my ...
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How does changes in vertex data work?
I have been learning computer graphics and for some time and can't seem to wrap my head around one concept. How to handle vertex data changes?
Ex. 1. I have a text rendering on a screen. And up on ...
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217
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How does Unreal Engine 5's Lumen (most likely) implement reflections?
In this YouTube video, the creator mentions that reflections in Unreal Engine 5's Lumen "work by tracing the path of light as it bounces off of surfaces in the game world." Does this mean ...
- 159
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266
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Raytracing in OpenGL or Vulkan?
I was looking at this glass ball rendering with an image inside of it (zoom out to see the glass ball), and noticed that it looks like they simulate the refraction of light as it crosses from inside ...
- 159
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104
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Custom LookAt and Perspective Matrix functions not rendering in Vulkan
I am trying to create a custom math library for a renderer. The renderer works when using glm but for educational purposes as well as for the sake of having a custom library to support multiple ...
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86
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Porting from DXR/HLSL to Vulkan Ray Tracing Extension/GLSL
I am working on the port of a demo from DXR to Vulkan Ray Tracing extension using GLSL.
In DXR/HLSL space, there are RayTMin() and RayTCurrent() functions to retrieve the starting and the current end ...
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66
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Is there a good rule of thumb for the optimal / maximum number of instances to draw in a single call?
So let's say I want to draw a lot of textured quads to the framebuffer.
In each shader invocation, I will bind an array of indicies, an array of positions, and an array of textures to index into. ...
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211
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How to do frustum culling with draw call bundling?
If I'm understanding things correctly (please correct me if I'm wrong):
All modern graphics APIs (vulkan, dx12, metal, webgpu) provide ways to bundle and replay draw calls. The bundle includes which ...
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103
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Vulkan Ray Tracing analogue of Optix's OPTIX_BUILD_INPUT_TYPE_CURVES
Optix has OPTIX_BUILD_INPUT_TYPE_CURVES to model splines. The SDK comes with an example named optixHair.
I could not find something like this under Vulkan RayTracing Extension, how could one implement ...
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85
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adding a compute shader after a pipeline
I am writing a program to add a compute shader after rendering my image, and add a graphics pipeline after the compute shader to present the final image.
I have a question though. How should I set the ...
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118
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What causes buffer access to be significantly slower in DXIL than SPIR-V?
I am currently experimenting with unbounded descriptor arrays and ultimately want to use bindless descriptors. I wrote a test application, that draws 100.000 simple object instances, where the ...
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162
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bilateral filter in vulkan
I am supposed to use bilateral filter to denoise my image rendered with Vulkan. I wonder how I should implement the method. Should I add the rendered image to another frag shader as a texture and ...
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81
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multithread rendering performance
I am simulating multiple users rendering with my program on my computer with multiple threads. I wonder why my fps counter tells me that the performance on all threads is the same, regardless of the ...
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320
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exporting the final image from Vulkan
I wish to render an image with my vulkan program and save it to local path. What's a good way to do this or has anyone done it before?
Thanks!
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116
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What are some tools to test performance of a Vulkan based game?
I am developing Vulkan games. It is still a basic rendering program with some cornel boxed data. Apart from testing hairs, calculating fps, what are some tools to apply to test the performance of such ...
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293
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Problem when passing a readonly image2D to a function
I would like to declare a function which reads from an image2D and modifies the output.
My shader is written like so:
...
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519
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Is there a cost to querying a texture size inside a GLSL shader?
So I need to have a texture size for my compute shader. I found this function in GLSL to query this inside the shader:
ivec2 textureSize = imageSize(outputImage)
...
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195
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Having trouble understanding advection from GPU gems fluid dynamics example
So I am trying to implement a fluid simulation, as described in Chapter 38 of GPU Gems.
I am also drawing heavily from the excellent implementation by Pavel.
Where I'm getting a bit stuck is with ...
- 159
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522
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rendering in two windows
I want to render on two windows. What are some stuffs that I should share, and what stuffs should I separate? I have a rendering program in Vulkan and want to add a window to it. It seems that I need ...
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237
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How Anisotropic filtering works
I would like to understand how anisotripic filtering works in gpu.
Specifically what is the minimum state in which the texture needs to be in for anisotropic filtering to work.
by state of the texture ...
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289
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what is the output from rasterizer
what exactly does the rasterizer outputs as per my knowlage it outputs primitives rasterized as fragments which seems correct as the next step in vulkan/opengl is fragment shader but dx confuses me ...
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214
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Vulkan abstraction similar to OpenGL?
Because OpenGL is deprecating, I was wondering where to position myself to keep on learning graphics programming in the years to come on the same level of abstraction as OpenGL ? I don't want to go ...
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138
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Text rendering - weird outline when zoomed
I'm writing a simple text editor using Vulkan for rendering, and I'm seeing some strange outline around the rendered letters if I take a screenshot of the text and zoom in, which bothers me because I ...
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A lot of pipelines on Vulkan for each render pass, what could go wrong?
I would like to represent creation for each 2D shape or bitmap effect as a pipeline. The only purpose of this to modularize algorithms because extendibility is a big deal for current project. However, ...
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1k
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vulkan perspective matrix vs opengl perspective matrix
Hi I have a slight confusion in using the opengl perspective matrix in vulkan.
glm's perspective matrix works directly in vulkan just by multiplying the "[1,1 term by -1 but when I compared the ...
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842
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Is drawing Bezier curve with scanline algorithm possible with Vulkan?
As an information, Vulkan is a low-level abstraction layer thru modern GPU. It allows programmers to program the GPU and assemble rendering pipeline. On that pipeline, there are modules of program ...
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378
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How can I implement subpixel antialiasing for font rasterization in Vulkan?
As a hobby project I am creating text rendering application that renders text directly from glyph outlines. Currently I am trying to find info on how to implement subpixel antialiasing. I know that ...
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564
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Vulkan Queue (Family), Command (pool) and Hardware usage
I have some questions about the GPU usage of Queues / Queue families, command buffer / pool.
I am reading the Book: ...
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119
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Time Interval Ray Tracing performance
I found a very nice paper regarding Time Interval Ray Tracing for Motion Blur published in 2017. That was before RTX GPUs were on the market.
I have a few questions about an optimal implementation and ...
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225
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Mesh-Shader and layered rendering
In the usual pipeline (vertex, tessellation, geometry and fragment shaders) the geometry can be deformed and in the geometry shader it is possible to copy the generated and deformed geometry in order ...
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90
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Level of detail passed from vertex shader to fragment shader
I am looking at a sample code from a respected source and the mipmap level-of-detail parameter (float) is passed to the vertex shader as a uniform which then passes to the fragment shader without ...
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45
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Offsetting value in shader causes unexpected/wrong logic
Let me explain what I am doing. I am trying to reduce the memory footprint of a voxel based algorithm by storing the voxel data as a hash map in an SSBO, as opposed to a 3D image.
I am visualizing the ...
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82
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DirectX FVF(Flexible Vertex Format ) equivalent in OpenGL/Vulkan?
Is there any directX FVF(Flexible Vertex Format ) equivalent in OpenGL/Vulkan.
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556
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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 ...
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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:
...
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1k
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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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107
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How do fragment shader invocations subgroups map onto triangles?
Should I expect that every invocation/fragment within a subgroup, when using something like subgroupBroadcast(), will belong to the same triangle?
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GLSL Compute Shader Setting "shared" memory buffer size
Is it possible to set the size of the shared memory of a compute shader workgroup from the host code? There is a way to do this in CUDA and I am suspecting that, since there is an GLSL extension to ...
- 299
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251
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imageLoad() behavior for non-existent texel
Is there a way to influence the behavior of imageLoad() for accessing an image2D or uimage2D ...
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868
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Vulkan clear color is wrong
I am following https://vulkan-tutorial.com/Introduction to get myself familiar with the Vulkan API. I have gotten to the point where my application is able to draw a triangle. But for some reason the ...
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