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ArjinFerman  Tinfoil Gigachad  25d ago (text post)   313 thread views

Tinker Tuesday for June 17, 2025

This thread is for anyone working on personal projects to share their progress, and hold themselves somewhat accountable to a group of peers.

Post your project, your progress from last week, and what you hope to accomplish this week.

If you want to be pinged with a reminder asking about your project, let me know, and I'll harass you each week until you cancel the service

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Alright looks like I made a breakthrough in unretarding the sql queries. Perhaps it's a bad sign that I had to work so much against the framework I'm working with, but I can't think of a better way. Have to chip away at a few more things, and then on to unretarding the content import / sync.

How are you doing @Southkraut?

Some concept work, some coding. No great accomplishments; just some basic refactoring to make working with Unreal C++ a little less painful. Working my way out of some Unreal problems, while failing to solve others. Not much, but I'm happy just go get anything at all done.

Homies: Ride or Die

Last week I got wheels rotating. Since then I've also added steering.

In the meantime I learned it doesn't work on my laptop at all since my GPU on that is much weaker. I traced it down to the skydome rendering and added a flag so I could disable it while away from my desktop. Not sure why it pwns the GPU so much. The skydome isn't particularly high res but perhaps I tesselated it into way way too many triangles. Time to dust off the Blender workflow again.

Separately I noticed there's a problem with how the wheels spin and play with the ambient sunlight. The light appears to get painted onto one section of the wheel and it spins around the wheel with it, which is obviously wrong.

I spent a few days on this and haven't made much progress. I'm kind of pulling my hair out.

There's clearly something wrong with matrix math but not entirely sure what. I first SRT (scale rotate translate) the car from world space into view space. Before I submit that rendering, I detect if a given submesh involves a wheel and do a further R to the matrix. This makes the wheels rotate perfectly with velocity, but I guess screws the lighting calculations up. Maybe the matrix math accidentally works for vertex shading but not normals calculation, though I think I'm doing the right things to isolate them.

I would add debug printfs but half of this shit is happening in the bgfx shader language so my debugging visibility is limited. Maybe there are tools for this...

TRON bike lighting

Slow progress. Forgot that I needed more JST-SM 4 pin connectors, so placed an order. Then I remembered that soldering even a few spots gives me a scratchy throat and maybe a headache and it could be because I'm breathing in the soldering smoke from having my face so close to it. So, I need an extractor fan.

Of course I couldn't just buy an extractor fan like a normal person, because I stumbled across a DIY one in this Great Scott video right when I realized this.

https://youtube.com/watch?v=Nb78wF1Tkwc&t=55s

Update.

Separately I noticed there's a problem with how the wheels spin and play with the ambient sunlight. The light appears to get painted onto one section of the wheel and it spins around the wheel with it, which is obviously wrong. I spent a few days on this and haven't made much progress. I'm kind of pulling my hair out.

I finally decided to look at the "normal map" for the wheel and notice it's ... painted on looking? The top right of the circle is dark and the bottom left is shiny which is the behavior I'm running into. As the wheel spins the shine "follows" it towards the ground and then up the back until it loops around again.

/facepalm

Looks like the person who made this model didn't ever expect the wheels to actually turn, which you know, fair. Surprised they did this because the rest of the car relies on reflecting the ambient lighting instead of painted on lighting.

I'm embarrassed it took me this long to decide to check the data.

EDIT: fuck, that's not actually the problem. the normals map is not a shade map. it makes sense that the "color" at one end of a circle is different from the other end

/images/17502758176521997.webp

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