repository·master·Indexed 42 days ago
https://github.com/amansachan1/meteorosA high-performance, real-time volumetric cloudscape renderer built with Vulkan, inspired by the NUBIS system used in Guerrilla Games' Decima Engine.
GLFW is an open-source, multi-platform library designed for OpenGL, OpenGL ES, and Vulkan application development. It provides a platform-independent API for common windowing and input tasks, including:
Supported Platforms:
License: zlib/libpng license.
GLM is a header-only C++ mathematics library designed for graphics software. It is based on the OpenGL Shading Language (GLSL) specifications, meaning it uses the same naming conventions and functionality as GLSL. This allows developers familiar with GLSL to use the same logic in C++.
Key features include:
The current implementation includes:
ImGui typically has zero frames of lag for most behaviors, but some behaviors may have one frame of lag. At 60 FPS, this is generally unnoticeable, but you may notice a difference between hardware-accelerated OS cursors and GPU-rendered software cursors.
To visualize or manage this, you can use the io.MouseDrawCursor flag. This requests ImGui to draw the mouse cursor itself, which can help you visualize the lag between a hardware cursor and a software cursor. It may be beneficial to switch to a software-rendered cursor when an interactive drag is in progress to improve user experience.
Reprojection is implemented using the following technical steps:
[0,1], sample the pixel from the old frame to fill the current pixel.Large numbers of glyphs or multiple fonts can exceed graphics driver texture size limits. To minimize the resulting texture height/width:
io.Fonts.TexDesiredWidth: Specify a target texture width to control the aspect ratio.config.OversampleH (e.g., to 2 or 1) in ImFontConfig.GlyphRangesBuilder to only include necessary characters, or use specific range functions like GetGlyphRangesDefault(), GetGlyphRangesJapanese(), or GetGlyphRangesChinese() instead of loading full Unicode sets.On compilers that support anonymous struct as union members (like Visual C++), GLM_FORCE_SWIZZLE enables true GLSL-like swizzling, allowing both R-value and L-value expressions.
Note: Swizzle objects returned by this method are implementation-specific and implicitly convert to vector types. They cannot be passed directly to GLM functions; you must use an explicit constructor or the () operator.
Example of L-value usage:
ColorRGBA.bgra = ColorRGBA.rgba;Example of required conversion for GLM functions:
// ERROR: Color.rgba is not a vector type
vec4 ClampedA = glm::clamp(Color.rgba, 0.f, 1.f);
// OK: Explicit conversion
vec4 ClampedB = glm::clamp(vec4(Color.rgba), 0.f, 1.f);
// OK: Explicit conversion via operator()
vec4 ClampedC = glm::clamp(Color.rgba(), 0.f, 1.f);#define GLM_FORCE_SWIZZLE
#include <glm/glm.hpp>
using glm::vec4;
void foo()
{
vec4 Color(1.0f, 0.5f, 0.0f, 1.0f);
// Generates compiler errors. Color.rgba is not a vector type.
vec4 ClampedA = glm::clamp(Color.rgba, 0.f, 1.f); // ERROR
// Explicit conversion through a constructor
vec4 ClampedB = glm::clamp(vec4(Color.rgba), 0.f, 1.f); // OK
// Explicit conversion through operator()
vec4 ClampedC = glm::clamp(Color.rgba(), 0.f, 1.f); // OK
}Meteoros uses a compositing model where clouds are generated first, then rasterized geometry is painted over them, followed by god-ray effects.
All strings used in ImGui must be encoded in UTF-8. Using local code pages (like CP-923 or CP-1251) in your source code will not work.
In C++11 and later, you can use the u8"string" syntax to ensure literals are UTF-8 encoded:
ImGui::Text(u8"hello");
ImGui::Text(u8"こんにちは");Alternatively, you can manually convert strings to UTF-8 or load text data from files that are already saved in UTF-8 format. You can also use font->AddRemapChar() to map local codepage characters to Unicode codepoints, though this may cause issues for international contributors.
Meteoros employs several optimization strategies to maintain performance during volumetric cloud rendering:
Meteoros uses ray marching, an image-based volumetric rendering technique, to render clouds. Unlike surface rendering, ray marching evaluates volumes by sampling a ray at various points along its length.
The Rendering Pipeline:
Optimization: Instead of naive ray shooting for lighting, Meteoros uses Cone Sampling. This involves taking 6 samples within a cone aligned with the light source. The final sample is placed further away to account for potential occlusion by distant clouds.