BeRo's Blog

Memory management in Vulkan is a complex and intricate process that gives developers control over how graphics memory is allocated and used. The primary principle of Vulkan’s memory management is that it offers a lower-level interface to the GPU than APIs like OpenGL, entrusting developers with the responsibility of managing memory allocations themselves. This can lead to more efficient use of memory and enhanced performance, but it also necessitates a deeper understanding of how the GPU operates and the optimal way to manage its resources.

In Vulkan, memory is organized in a hierarchy that includes heaps, memory types, and memory property flags. Heaps are fixed-size memory resources exposed by the device, and each heap can support different memory types. When creating a resource like a buffer, Vulkan provides information about which memory types are compatible with that resource. Depending on the resource’s usage flags, the developer must select the right memory type and, based on that type, the … (read more)

I'm making progress with the GLTF 2.0 support in PasVulkan, but I'm still thinking about how to implement everything effectively so that as few draw calls as possible are necessary. The current plan is to pack everything in storage buffers, so that the vertex shaders always have the complete information about everything at any time such as for example morph targets, joints/bones, node transformations, etc. Because then the CPU only needs to update the most necessary and upload to the GPU what is necessary, the rest will be done by the GPU itself then. So stay tuned! 

Today I present you my GLSL Astronomy compute shader, which I use in my demo productions and games. ☺

// Copyright (C) 2018, Benjamin "BeRo" Rosseaux (benjamin@rosseaux.de) - License: CC0// Hint: It's not super accurate, but it should be good enough for games and demos with sky rendering.#version 430


layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
uniform vec3 tc; // Time constant


layout(std430) buffer ssboAstronomy {

   vec3 sunPosition;

   float sunDistance;

   vec3 moonPosition;

   float moonDistance;

   float moonPhase;

   mat3 celestialTransform;

};
const float HalfPI = 1.5707963267948966, // 1.570796326794896619231,

            PI = 3.141592653589793, // 3.141592653589793238463,

            PI2 = 6.283185307179586; // 6.283185307179586476925
// The AMD windows GPU drivers do not seem to like constant double precision values here, // so no const prefix in this case.double astronomicalUnitsToKiloMeters = 149597871.0;
const vec2 sinCosOffsets = vec2(0.0, HalfPI);
double … (read more)