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PBR Lighting in Vulkan

PBR Lighting in Vulkan

I now have point and spot lights working (without shadows) in the Vulkan renderer. Here are the results, with both "Physically-based rendering" (PBR) and Blinn-Phong shaders: Without the IBL contribution it's not terribly impressive, but this is progress.

Josh

Josh

Early Z-Pass in Vulkan

Early Z-Pass in Vulkan

Vulkan is pretty wonderful because I can take all the optimal techniques I worked out in OpenGL and it just makes everything much faster. I've successfully completed the implementation of early Z-pass, which is important for our lighting system. We are using a forward clustered renderer, similar to the technique id Software's new DOOM games use. Because the fragment shader is fairly intensive, a depth pre-pass is rendered to ensure we only process each screen pixel once. This techniqu

Josh

Josh

Lighting in Vulkan

Lighting in Vulkan

I have basic point lights working in the Vulkan renderer now. There are no shadows or any type of reflections yet. I need to work out how to set up a depth pre-pass. In OpenGL this is very simple, but in Vulkan it requires another complicated mess of code. Once I do that, I can add in other light types (spot, box, and directional) and pull in the PBR lighting shader code. Then I will add support for a cubemap skybox and reflections, and then I will upload another update to the beta. S

Josh

Josh

Turbo Game Engine (Leadwerks 5) beta updated with Vulkan renderer

The beta of our new game engine has been updated with a new renderer built with the Vulkan graphics API, and all OpenGL code has been removed. Vulkan provides us with low-overhead rendering that delivers a massive increase in rendering performance. Early benchmarks indicate as much as a 10x improvement in speed over the Leadwerks 4 renderer. The new engine features an streamlined API with modern C++ features and an improved binding library for Lua. Here's a simple C++ program in Turbo:

Josh

Josh

Little racing car game demo

This little game is here free to play: https://1drv.ms/u/s!AiVBgjDAyIXLs1khcglU6UKFbI_4?e=4oK8Sj   1] First step: Adapting the Spline tool to build what we need:  I combined some of the possibilities that offers the Spline Tool (great thing) to obtain all this in one: - Cars align and follow the roads (rotation) - While using Physics, and so collisions - While using reverse travel (cars go back on the road)     2] next step: 

Marcousik

Marcousik

New Texture Compression Formats

New Texture Compression Formats

The Vulkan renderer now supports new texture compression formats that can be loaded from DDS files. I've updated the DDS loader to support newer versions of the format with new features. BC5 is a format ATI invented (originally called ATI2 or 3Dc) which is a two-channel compressed format specifically designed for storing normal maps. This gives you better quality normals than what DXT compression (even with the DXT5n swizzle hack) can provide. BC7 is interesting because it uses the sam

Josh

Josh

Multiple shaders in Vulkan

I have it worked out now where the new engine will handle multiple shaders. The renderer groups meshes (renamed from "surfaces" in Leadwerks) by shader. A single draw call renders many batches of instances, with different materials applied. It's a very advanced and complex system, so something that was simple before, changing the shader, now requires a lot of code to make work! You can see here the barbed wire is using an alpha-discard shader that removes pixels while the rest of the scene uses

Josh

Josh

Textures and materials in Vulkan

Textures and materials in Vulkan

I now have different materials with textures working in Vulkan. The API allows us to access every loaded texture in any shader, although some Intel chips have limitations and will require a fallback. This is interesting because some of our design decisions in Leadwerks 4 were made because we had a limit of 16 textures a shader could access. Terrain clipmaps were a good solution to this problem, but since the same limitations no longer exist it may be time to revisit this design. We could, for ex

Josh

Josh

The Asset Loader Class

In Turbo (Leadwerks 5) all asset types have a list of asset loader objects for loading different file formats. There are a number of built-in loaders for different file formats, but you can add your own by deriving the AssetLoader class or creating a script-based loader. Another new feature is that any scripts in the "Scripts/Start" folder get run when your game starts. Put those together, and you can add support for a new model or texture file format just by dropping a script in your project.

Josh

Josh

Vulkan Render Pipeline

Having completed a hard-coded rendering pipeline for one single shader, I am now working to create a more flexible system that can handle multiple material and shader definitions. If there's one way I can describe Vulkan, it's "take every single possible OpenGL setting, put it into a structure, and create an immutable cached object based on those settings that you can then use and reuse". This design is pretty rigid, but it's one of the reasons Vulkan is giving us an 80% performance increase ove

Josh

Josh

Leadwerks and C#

Actually it is very simple. As usual, we need to export the functions we are interested in to the Dynamic Library (DLL), and then import them into our C# program. Let's start. C++ DLL The first thing we need is to create a project in C++ for our future DLL, and of course configure it for the Leadwerks engine Configuration for Release Right-click on the project and select Property. In the window that appears, go to the tab "С/C++" / "General". Copy and Paste to a "Additional In

IgorBgz90

IgorBgz90

Textures in Vulkan

Textures in Vulkan

I finally got a textured surface rendering in Vulkan so we now have officially surpassed StarFox (SNES) graphics: Although StarFox did have distance fog. 😂 Vulkan uses a sort of "baked" graphics pipeline. Each surface you want to render uses an object you have to create in code that contains all material, texture, shader, and other settings. There is no concept of "just change this one setting" like in OpenGL. Consequently, the new renderer may be a bit more rigid than what

Josh

Josh

Single-file SPIR-V shaders for Vulkan

Single-file SPIR-V shaders for Vulkan

It is now possible to compile shaders into a single self-contained file that can loaded by any Vulkan program, but it's not obvious how this is done. After poking around for a while I found all the pieces I needed to put this together. Compiling First, you need to compile each shader stage from a source code file into a precompiled SPIR-V file. There are several tools available to do this, but I prefer GLSlangValidator because it supports the Google #include extension. Put your vertex

Josh

Josh

Vulkan Progress

Vulkan Progress

I was going to write about my thoughts on Vulkan, about what I like and don't like, what could be improved, and what ramifications this has for developers and the industry. But it doesn't matter what I think. This is the way things are going, and I have no say in that. I can only respond to these big industry-wide changes and make it work to my advantage. Overall, Vulkan does help us, in both a technical and business sense. That's as much as I feel like explaining. Beta subscribers ca

Josh

Josh

Memory Management in Vulkan

Vulkan gives us explicit control over the way data is handled in system and video memory. You can map a buffer into system memory, modify it, and then unmap it (giving it back to the GPU) but it is very slow to have a buffer that both the GPU and CPU can access. Instead, you can create a staging buffer that only the CPU can access, then use that to copy data into another buffer that can only be read by the GPU. Because the GPU buffer may be in-use at the time you want to copy data to it, it is b

Josh

Josh

Buffers in Vulkan

Buffers in Vulkan

I've now got the Vulkan renderer drawing multiple different models in one single pass. This is done by merging all mesh geometry into one single vertex and indice buffer and using indirect drawing. I implemented this originally in OpenGL and was able to translate the technique over to Vulkan. This can allow an entire scene to be drawn in just one or a few draw calls. This will make a tremendous improvement in performance in complex scenes like The Zone. In that scene in Leadwerks the slow step i

Josh

Josh

First Vulkan Performance Results

Using my box test of over 100,000 boxes, I can compare performance in the new engine using OpenGL and Vulkan side by side. The results are astounding. Our new engine uses extensive multithreading to perform culling and rendering on separate threads, bringing down the time the GPU sits around waiting for the CPU to nearly zero. Hardware: Nvidia GEForce GTX 1070 (notebook) OpenGL: ~380 FPS Vulkan 700+ FPS. FRAPS does not work with Vulkan, so the only FPS counter I have is

Josh

Josh

Uniform Buffers in Vulkan

Uniform Buffers in Vulkan

Following this tutorial, I have managed to add uniform buffers into my Vulkan graphics pipeline. Since each image in the swapchain has a different graphics pipeline object, and uniform buffers are tied to a pipeline, you end up uploading all the data three times every time it changes. OpenGL might be doing something like this under the hood, but I am not sure this is a good approach. There are three ways to get data to a shader in Vulkan. Push constants are synonymous with GLSL uniforms, althoug

Josh

Josh

Command Buffer Synchronization in Vulkan

Command Buffer Synchronization in Vulkan

The Vulkan graphics API is unbelievably complex. To create a render context, you must create a series of images for the front and back buffers (you can create three for triple-buffering). This is called a swap chain. Now, Vulkan operates on the principle of command buffers, which are a list of commands that get sent to the GPU. Guess what? The target image is part of the command buffer! So for each image in your swap chain, you need to maintain a separate command buffer  If anything changes in y

Josh

Josh

Vulkan Shader Compilation

One of the best points of Vulkan is how shaders are loaded from precompiled Spir-V files. This means GLSL shaders either work or they don't. Unlike OpenGL, there is no different outcome on Intel, AMD, or nVidia hardware. SPIR-V files can be compiled using a couple of different utilities. I favor LunarG's compiler because it supports #include directives. Shader.vert: #version 450 #extension GL_ARB_separate_shader_objects : enable #include "VertexLayout.glsl" layout(push_constant) unifo

Josh

Josh

Vulkan Shader Uniforms

In Vulkan all shader uniforms are packed into a single structure declared in a GLSL shader like this: layout(push_constant) uniform pushBlock { vec4 color; } pushConstantsBlock; You can add more values, but the shaders all need to use the same structure, and it needs to be declared exactly the same inside the program. Like everything else in Vulkan, shaders are set inside a command buffer. But these shader values are likely to be constantly changing each frame, so how do you hand

Josh

Josh

Compatibility Wrapper

While we have Leadwerks today to make our apps, Turbo is currently in development. To make my projects more long term, I decided to take a step back from my VR project and create a wrapper class that apps can use to more easily transfer to the new engine.  Keep in-mind, this doesn't cover everything and I'm used the last beta from November for testing so things can change. Regardless, as long as that bridge is made, I can always go back and edit the Turbo stuff as more things come online. The go

reepblue

reepblue

Vulkan Nitty-Gritty

I am surprised at how quickly Vulkan development is coming together. The API is ridiculously verbose, but at the same time it eliminates a lot of hidden states and implicit behavior that made OpenGL difficult to work with. I have vertex buffers working now. Vertices in the new engine will always use this layout:     struct VkVertex     {         float position[3];         float normal[3];         float texcoords0[2];         float texcoords1[2];         float tangent[3];         unsigned cha

Josh

Josh

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