Questions tagged [texture]

For questions related to textures: procedural generation, encodings, aspect characterisation, filtering, mapping, storage...

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36 views

BC7 texture with alpha has the same size as BC7 without alpha

So i've a made a texture. I've saved the RGB one with BC7 compression, then added alpha channel[specular map] with varying levels of grayscale, and saved the file again as RGBA with BC7 compression. ...
1
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2answers
56 views

What's more optimal - sampling one channel at a time or all channels at once?

I'm going through and optimizing some of my glsl code for a project, and have come across a scenario several times that I am not sure how best to optimize. In summary - Is it faster to sample a ...
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0answers
13 views

Custom Create Maps in OpenGL

I am trying to create some procedurally created terrains for which i need to create noise maps. How do I create a texture of noise map in OpenGL and then pass that in my vertex shader as a heightMap? ...
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0answers
24 views

Generate hardcoded texture data to pass to shaders

I'm trying to manually create a color data to load as a texture with OpenGl for learning purposes. I created an unsigned char array consisting of 4 pixels with 3 ...
2
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1answer
130 views

Texture loading- erratic working

I'm a noob to the OpenGL world and am picking up ideas through practice. I've been writing some code to build retro-arcade games recently and need to load textures to provide the graphic interface. I'...
0
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0answers
19 views

Projective Texture Mapping when Texture Comes from a Framebuffer? Incorrect Texture Coordinates?

I am trying to perform a projective texture mapping using a texture which I generate by first drawing it to a framebuffer, so that I can dynamically generate a reflection which interacts with the ...
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0answers
20 views

Help needed with AI generated texture

I need to process sets of pictures (1 to 10 real life photos) from mammals to produce 3d models. I need to automate this process: 1. normalise colors among the set; 2. turn the set of real photos ...
0
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0answers
53 views

Is linear interpolation in a 2D texture possible (not quadratic like bilinear interpolation)?

I am currently studying for a computer graphics exam and on the slides about bilinear interpolation it is said that it is in reality quadratic interpolation. An (on the slides) unanswered question ...
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0answers
34 views

Sampling the depth component of a packed depth-stencil texture while rendering to its stencil component

I need to frequently perform depth testing for any given fragment at a different fragment location than the one rendered to. Since this isn't possible with normal builtin OpenGL depth testing ...
2
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1answer
37 views

2D array texture with different filtering setting per texture?

Currently I have textures which need GL_NEAREST and some other need GL_LINEAR in the same texture2dArray. In the shader I perform a manual GL_NEAREST lookup via textureFetch(). To avoid this my ...
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0answers
22 views

Algorithm to reproject texture after wrapping mesh using ICP?

I was watching this video, where given a base mesh we wrap it in a scanned mesh, I can imagine how to implement something similar from scratch, but I was wondering how can I assign uv coordinates to ...
1
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0answers
31 views

Optimizing texture fetches with higher mip levels

Let's say I have some shader program in DirectX or OpenGL rendering a full screen quad. And in a pixel/fragment shader I sample some huge textures at random texture coordinates. That is one same ...
1
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1answer
118 views

convert image pixel dimensions to UV

Hi i am rather new to computergraphics but i am trying to map an equirectangular image (360 video) to the inside of a sphere now i found the following formula to do this. ...
3
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2answers
199 views

What does texture resolve mean?

In the context of render targets or textures, what does "resolve" mean? For example: To resolve a color texture. From my understanding, it seems to mean, "copy but process/convert at the same time", ...
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0answers
80 views

Why is glUniform1i() returning GL_INVALID_VALUE?

I have a sampler variable in a shader: uniform sampler2DArray tiles; Which I am trying to bind to a texture unit in GL: ...
2
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1answer
128 views

Zero-copy texture reading from CPU memory

The Intel 740 AGP graphics card read textures directly from system RAM, using VRAM exclusively for depth buffers and the framebuffer. This has the effect of saving video RAM, and it could be ...
0
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0answers
40 views

I have found that the Gloss is the inverse of the roughness. Will simply inverting the gloss map work for roughness

I am using Substance Painter and an Adobe Fuse character. Fuse outputs a gloss map, and sp wants a roughness map. Would inverting the colors in a program like Photoshop work to switch it over?
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0answers
40 views

Is there a way to animate 'Tiling' of UV map using GLSL or Shader Language?

I'm looking for a way in where I could not only change the Texture UV Map 'Tiling' inside of Unity, but animate it by just having the 'X' go back and forth now and then from like 0.98 to 1.02 or ...
0
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0answers
24 views

How to visualize a dataset , generated in curvilinear grid, in opengl with texture maping?

I have a dataset obtained from astronomical simulation. This data was created in a curvilinear grid with polar coordinates. The form of this dataset is a simple array (1d) of intensities, i can ...
1
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0answers
16 views

How can I detect if an edge has flipped during the UV unfold process?

I'm writing my own UV Unfold operation (similar to Maya's Optimize UV tool or 3DS Max's Relax Tool). My code works great 90% of the time but in some instances, I'm getting faces and edges that flip ...
0
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0answers
133 views

Inverse texture mapping

I have a textured 3D object and looking for ways to transform back the texture. Effectively, I think this is an inverse texture mapping task. Do you know of anything close to this? Some papers or ...
4
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0answers
90 views

Are there any reasons to use power of two textures with modern mobile platforms?

Are there any reasons to use power of two textures (like 128x128 sized) if one targets modern mobile platforms (with OpenGL ES 3.0, Metal and/or Vulkan)? With iOS the PVRTC only supports power of two ...
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0answers
108 views

Which is more important : Texel or Pixel rate? [closed]

I would like to know which is the most important ? More particularly in games or for the display of a desk (ex KDE Plasma, Windows 10 ...) ?
1
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0answers
45 views

Where to find BRDF textures

I've read about measured BDRFs and models like cook-torrance have parameters that need to be set. It isn't hard to imagine that these parameters and the measured properties would vary from point to ...
0
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0answers
23 views

Visualize a mesh with sparse vertex counts

I have a mesh that records some integer information for its vertices. I expect this information to be quite sparse, with possible large variations. How could I visualize this on a colorscheme (e.g. ...
-1
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2answers
214 views

Why does Cubemap have 6 individual textures?

I am learning about Cubemap and I learned that A cubemap is basically a texture that contains 6 individual 2D textures but my question is Why does it contain 6 individual texture ? and also I've read ...
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0answers
49 views

Why cache working set per multiprocessor for texture memory in Nvidia has a variable size?

I saw it here https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#features-and-technical-specifications__technical-specifications-per-compute-capability , I don't know if it also happens ...
0
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1answer
196 views

Unity: Pass texture pointer from OpenGL to Unity

I'm working on a scene in Unity where I have textures loaded at runtime. As a result of that, the scene is being slowed down (even with co-routines), so I thought maybe I could move the texture ...
1
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1answer
210 views

Nice way to make noise seamless (without tampering with the noise generator)

Here's the problem : I have multiple noise generators in my program I Can't change. Perlin Noise, Diamond Square, Voronoi, etc. Unfortunately for me, I want the noise to be tileable, no matter the ...
0
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1answer
299 views

Sphere Texture Mapping Algorithm

I am trying to generate UV coordinates automatically to map a texture on a sphere. The problem is with seams when going from 0.8 to 0.2 there is a discontinuity and interpolation in fragment shader ...
1
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0answers
50 views

Anti aliasing thin features in textures

Assume I have a texture with a repeating line pattern. The lines are exactly 2 texels wide (really thin). Ans very spaced out (50 texels in between each line). I am now struggling with the ...
3
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0answers
79 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 ...
1
vote
1answer
131 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 ...
1
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1answer
179 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 ...
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0answers
346 views

Why do perspective correction based texture mapping do depth division

I'm currently trying to understand how works perspective correction texture mapping. I saw that actually it works by interpolating the z value of the three point of the triangle which the current ...
1
vote
1answer
44 views

Make a texture a clickable Button

What would be the best way to make a texture a clickable button? Suppose I have a Room (respresented by a 2D texture), where there are buttons. Would I in the main loop: check when the mouse is ...
1
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1answer
364 views

Texturing an “infinite” plane

I am rendering an infinite plane as described in the following answers: https://stackoverflow.com/questions/12965161/rendering-infinitely-large-plane https://stackoverflow.com/questions/7380250/how-...
1
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1answer
60 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
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1answer
513 views

How do I convert a hit on an infinite plane to UV coordinates for texturing in a Raytracer?

I am trying to convert a ray hit on an infinite plane, defined by an origin and a normal vector, into UV coordinates, so I can find the appropriate texel at that point. Code I have is close to ...
0
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2answers
78 views

Why is precalculating a distortion different from calculating it in the shader?

I have an application where I simulate a camera distortion. There are two ways to go about it: calculate the distortion per pixel in the shader or precalculate the distortion and store the distortion ...
2
votes
1answer
701 views

Is a single shader and 1x1 pixel white sampler more efficient than frequent switching between shaders with and without samplers?

I have some existing OpenGL code that I am porting to Vulkan. The question is somewhat relevant to both OpenGL and Vulkan. I am rendering some primitives using textures, some single channel, others ...
1
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1answer
75 views

In texture mapping, should we set texture coordinate to every vertex or can I skip vertices in between?

I am working on a texture mapping problem. I use vtk C++ library for my work. I have a very dense mesh with lots of vertices. I want to apply image texture to this mesh. Should I set texture ...
2
votes
2answers
497 views

Which graphics APIs texture formats are HDR texture formats?

I understand that HDR files are images encoded with a higher precision in order to keep more details. When loading such images in real-time rendering applications using common Graphics APIs (DirectX, ...
1
vote
2answers
357 views

WebGL - issues doing a simple texture downsample

I'm working on an image processing app which uses WebGL to apply shaders to a bunch of input photos. At one point in the algorithm, I need to create some image pyramids where I downscale the input ...
4
votes
1answer
183 views

How to apply wire texture for realistic rendering of embroidery?

I am building an algorithm which takes a bitmap image as input and render the image as an embroidery design. The different steps are : Vectorize the image, I keep only 5 colors (Done) Generate ...
1
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0answers
210 views

Generating Mip Maps For A Cube Map

Let's say I have a cube map that has a resolution of 256x256 for each face and I want to generate mip maps for it using a box filter. It's tempting to just mip each face individually, cutting the ...
1
vote
1answer
120 views

Issue with loading a texture on the GPU with OpenGL 4.1 Core profile

I’ve been trying to render a texture on the whole screen in OpenGL 4.1 using the Core profile and followed a few tutorials on the matter, but all I have so far is a blank screen. I tried using my ...
1
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0answers
563 views

OpenGL - Fit High/Low Resolution Image/Texture to a particular size Window

Consider a ray tracer written in OpenGL and using GLFW as a window toolkit. There are basically 2 options to display the ray-traced image. 1) Create a RenderBuffer ...
0
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1answer
93 views

Texture units parameters in OpenGL

I am writing a procedural terrain renderer for OpenGL. To shade the terrain I use multitexturing, that is 4 material textures and a blend map which distributes them across the terrain (encoded in RGBA)...
2
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0answers
75 views

Cem Yuksel's “Mesh colors” implementation/demo?

Are you aware of any sample implementation or demo application of Cem Yuksel's "Mesh Colors" or "Mesh Color Textures" (http://www.cemyuksel.com/research/meshcolors/) ? The author does not provide any ...