Midjourney is an AI art generator you can interact with on Discord to make content for your game engine. To use it, first join the Discord channel and enter one of the "newbie" rooms. To generate a new image, just type "/imagine" followed by the keywords you want to use. The more descriptive you are, the better. After a few moments four different images will be shown. You can upsample or create new variations of any of the images the algorithm creates.
And then the magic begins:
The VK_KHR_dynamic_rendering extension has made its way into Vulkan 1.2.203 and I have implemented this in Ultra Engine. What does it do?
Instead of creating renderpass objects ahead of time, dynamic rendering allows you to just specify the settings you need as your are performing filling in command buffers with rendering instructions. From the Khronos working group:
In my experience, post-processing effects is where this hurt the most. The engine has a user-defined stack of post-pro
When it comes to complex projects I like to focus on whatever area of technology causes me the most uncertainty or worry. Start with the big problems, solve those, and as you continue development the work gets easier and easier. I decided at this stage I really wanted to see how well Vulkan graphics work on Mac computers.
Vulkan doesn't run natively on Mac, but gets run through a translation library called MoltenVK. How well does MoltenVK actually work? There was only one way to find out...
As I have explained before, I plan for Ultra Engine to use glTF for our main 3D model file format, so that your final game models can be easily loaded back into a modeling program for editing whenever you need. glTF supports a lot of useful features and is widely supported, but there are a few missing pieces of information I need to add into it. Fortunately, this JSON-based file format has a mechanism for extensions that add new features and data to the format. In this article I will describe th
Recently I came across a problem where HDRI images I loaded and converted into cube maps looked simultaneously too bright and too dark.
I found that a simple linear to sRGB conversion made the images look as I would expect.
I have read about sRGB and linear color spaces before, but for some reason this time it just clicked and I understood. Maybe since I am not longer dealing with low-level Vulkan nonsense, I have extra mental capacity to spend on more high-level concepts l
Heat haze is a difficult problem. A particle emitter is created with a transparent material, and each particle warps the background a bit. The combined effect of lots of particles gives the whole background a nice shimmering wavy appearance. The problem is that when two particles overlap one another they don't blend together, because the last particle drawn is using the background of the solid world for the refracted image. This can result in a "popping" effect when particles disappear, as well
Previously I noted that since Voxel global illumination involves calculation of direct lighting, it would actually be possible to do away with shadow maps altogether, and use voxels for direct and global illumination. This can eliminate the problems of image-based shadows like shadow acne and adjusting the shadow map size. I also believe this method will turn out a lot faster than shadow map rendering, and you know how I like fast performance.
The sparse voxel octree node structure consume
Google Draco is a library that aims to do for mesh data what MP3 and OGG did for music. It does not reduce memory usage once a mesh is loaded, but it could reduce file sizes and improve download times. Although mesh data does not tend to use much disk space, I am always interested in optimization. Furthermore, some of the NASA models I work with are very high-poly, and do take up significant disk space. Google offers a very compelling chart showing a compression ratio of about 95%:
Ho
I've been working hard getting all the rendering features to work together in one unified system. Ultra Engine, more than any renderer I have worked on, takes a lot of different features and integrates them into one physically-based graphics system. A lot of this is due to the excellent PBR materials system that Khronos glTF provides, and then there are my own features that are worked into this, like combined screen-space and voxel ray traced reflections.
Anyways, it's a lot of di
Autodesk 3ds Max now supports export of glTF models, as well as a new glTF material type. The process of setting up and exporting glTF models is pretty straightforward, but there are a couple of little details I wanted to point out to help prevent you from getting stuck. For this article, I will be working with the moss rocks 1 model pack from Polyhaven.
Getting geometry into 3ds Max is simple enough. I imported the model as an FBX file.
To set up the material, I opened the compa
I recently fired up an install of Ubuntu 20.04 to see what the state of development on Linux is now, and it looks like things have improved dramatically since I first started working with Linux in 2013. Visual Studio Code looks and works great on Linux, and I was able to load the Ultra Engine source code and start compiling, although there is still much work to do. The debugger is fantastic, especially after using the Code::Blocks debugger on Linux, which was absolutely sadistic. (They're both u
At long last, the engine that felt like it would never be done is here. This is all the result of an idea I had and wanted to put to the test. Of course I never anticipated it was possible to deliver a 10x improvement in rendering performance, but here we are with the benchmarks to prove it.
Research & Development
The last four years of research and development were an opportunity to rethink and redesign what a game engine should be. Along the way there were a few ideas I had that
I've actually been doing a lot of work to finalize the terrain system, but I got into tessellation, and another rabbit hole opened up. I've been thinking about detailed models in VR. Tessellation is a nice way to easily increase model detail. It does two things:
Curved surfaces get smoother (using point-normal triangles or quads)
A displacement map can be used to make small geometric detail to a surface.
These are really nice features because they don't require a lot of mem
Not a lot of people know about this, but back in 2001 Discreet (before the company was purchased by Autodesk) released a free version of 3ds max for modding games. Back then game file formats and tools were much more highly specialized than today, so each game required a "game pack" to customize the gmax interface to support that game. I think the idea was to charge the game developer money to add support for their game. Gmax supported several titles including Quake 3 Arena and Microsoft Flight
Not long ago, I wrote about my experiments with AI-generated textures for games. I think the general consensus at the time was that the technology was interesting but not very useful in its form at the time. Recently, I had reason to look into the OpenAI development SDK, because I wanted to see if it was possible to automatically convert our C++ documentation into documentation for Lua. While looking at that, I started poking around with the image generation API, which is now using DALL-E 2. Ste
Previously I described how I was able to save the voxel data into a sparse octree and correctly lookup the right voxel in a shader. This shot shows that each triangle is being rasterized separately, i.e. the triangle bounding box is being correctly trimmed to avoid a lot of overlapping voxels:
Calculating direct lighting using the sparse octree was very difficult, and took me several days of debugging. I'm not 100% sure what the problem was, other than it seems GLSL code is not quite
Attention: The addition of our custom model file format has changed the way this system works. Colliders are now saved into the Ultra MDL file.
I haven't been blogging much because I am making so much progress that there would be too much to cover. In this article I will talk about one little system I spent the last week on and show the improvements I have made to the workflow over Leadwerks.
In the asset editor, when the root of a model is selected, a "Collider" field appears in the p
Package plugins are now supported in Ultra Engine 1.0.2. This allows the engine to handle other package formats besides just ZIP. In order to test this out, I created the Quake Loader plugin, which currently supports the following formats used in the original Quake game:
PAK
WAD
BSP (textures)
SPR
LMP
Why Quake? Well, the original Quake game is what got me into game development through modding, but Quake is also great for testing because it's so weird.
This is an update on my progress of our voxel raytracing system. VXRT is designed to provide all the reflection information that PBR materials use. If a picture is worth a thousand words, then this counts as a 5000 word article.
Direct lighting:
Global illumination:
Specular reflection:
Skybox component:
Final combined image:
I wanted to take some time to investigate geospatial features and see if it was possible to use GIS systems with Ultra Engine. My investigations were a success and resulted in some beautiful lunar landscapes in a relatively short period of time in the new game engine.
I have plans for this, but nothing I can say anything specific about right now, so now I am working on the editor again.
Leadwerks had a very well-defined workflow, which made it simple to use but also somewhat limi
HDR skyboxes are important in PBR rendering because sky reflections get dampened by surface color. It's not really for the sky itself, but rather we don't want bright reflections to get clamped and washed out, so we need colors that go beyond the visible range of 0-1.
Polyhaven has a large collection of free photo-based HDR environments, but they are all stored in EXR format as sphere maps. What we want are cubemaps stored in a single DDS file, preferably using texture compression.
We'
After testing and some discussion with other programmers, I decided to try performing voxelization on the GPU instead of the CPU. The downside is the memory usage is much higher than a sparse voxel octree, but I found that sparse voxel octrees were very slow when it came to soft reflections, although the results of the sharp raycast were impressive:
You can read the details of GPU voxelization here if you wish.
Initially I thought the process would require rendering the
I have more than one light bounce working now, and it looks a lot nicer than single-bounce GI. The ambient light here is pure black. All light is coming off from the direct light, and bouncing off surfaces.
It will take some time to get the details worked out, and more bounces will require more memory. I'm actually kind of shocked how good looking it is. This is just a single 128x128x128 volume texture at 0.25 meters per voxel. Light leaks seem to be not a problem, even at that low re
Before proceeding with multiple GI volumes, I decided to focus on just getting the lighting to look as close to perfect as possible, with a single stage.
Injecting the ambient light into the voxel data made flat-lit areas appear much more "3D", with color bleeding and subtle contours everywhere.
Lighting only:
Lighting + albedo
Some adjustments to the way the sky color is sampled gave a more lifelike appearance to outdoor lighting.
Before:
After. N
I'm wrapping up the terrain features now for the initial release. Here's a summary of terrain in Ultra Engine.
Terrains are an entity, just like anything else, and can be positioned, rotated, or scaled. Non-square terrains are supported, so you can create something with a 1024x512 or whatever resolution. (Power-of-two sizes are required.)
Editing Terrain
Ultra Engine includes an API that lets you modify terrain in real-time. I took something very complicated and distilled it down
SCP
