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AboutHomeArtBlogAboutSometimes, just rarely, you can see how technology works behind the scenes without reading its code or prying off the panels to reveal the circuits and capacitors beneath. One of those moments, was while using Propper in the Source engine. That is, Source 1, now that Source 2 actually exists at the time of writing.
The Source engine's maps are built ontop of relatively simple Binary Space Partition (BSP, for short) files that are populated with additional map data (including other models, lights, anything that isn't explicitly world geometry really). BSP is made up of blocks. These blocks can be carved down into more complex shapes, but they can never feature concave geometry relative to its vertices, nor can they have faces that aren't entirely flat across all vertices. BSP simply cannot resolve these relatively 'basic' modeling tenets. If you make a concave face in Maya, you get the requisite vertices and rendering behavior. Faces with complex surfaces are auto-appended with divisions and breaks to make them possible. But not in BSP. BSP is entirely convex triangle modeling at its core, and concave faces must be made of various brushes. Brushes are the blocks and cube and triangles and odd shapes that make up a BSP file.
Usually, the BSP has some lighting baked onto its geometry, extra faces are culled, some visibility calculations are run specific to source, and we're off to the races. Except the version of Source I'm using came out in 2005. I was 6 when it released.
I don't think 6 year old me would think I would be using software released that year to get paid 12 years down the line, nor in a contemporary university modeling course.
Hammer, the map-editor or level-creation tool (really whatever you want to call it) is bundled with every copy of the Source Engine, and is the de-facto standard of a really good, but also awfully janky editor. It has elegance in some of its simplicity. Brick walls elsewhere. Hammer explicitly features creation tools restricted entirely to BSP creation. You can place 3D models within your BSP, but you can't make them.
Except you can, with Propper. Which brings me back to the original topic. Propper utilizes the binary (vbsp.exe) that the Source engine uses to compile and validate the BSP geometry, and instead uses the information there to compile into various different 3D modeling formats. And in bringing those models forward, the truth of BSP is brought to light. BSP is entirely convex triangle modeling at its core.
Ok. So what? Well, nothing really. I already knew that BSP was a limited format when I embarked on this journey. I knew full well that I'd have better success by just brute forcing myself through Maya 2020. And yet, the familiarity of the tools I already know beckon like a siren. Hammer is good. It can't be denied. Hammer feels good to use. The grid is constant even down to the smallest grid size. Proportions are kept in check by the player spawn point ominously floating in the level, and creation is simply familiar. Spaces are so much more real when you can smash F9, and walk around them for a bit before bringing them into Unity, or Maya, or whatever engine.
Is converting BSP geometry into .OBJ files and then cleaning them up in Maya tedious? Yes. But is the initial creation a bit faster? Probably not. But is it what I did to create an entire VR environment? Also yes.
I can't recommend it. But I will say, 3D modeling tools need better grid options. Grid options like Hammer.
