2D lights and shadows sample

The Defoldmine
#21

Edit: This appears to be my video card, as the example here also renders that way. I opened that link on another PC with an nVidia card, and it’s fine. I have an AMD RX 6800. I’m open to solutions, but I suspect this would be hard to troubleshoot without the same card/drivers. I’m on the latest drivers.

This doesn’t seem to be rendering correctly for me on the latest Defold 1.4.8. It’s as if the shadows are too close to the light source. I’ve included a screenshot of the sample from the repo and my own project where the same effect is happening. Is there a quick fix for this? I’m using this in a game jam that ends this weekend, so will need to find an alternative if I can’t get this to work. I’m not familiar with shader programming, and I’ll get lost deep in the woods for hours if I try to figure it out now.

Many thanks to everyone who’s contributed to this and some other extensions/libraries I’m using (I will surely list them in the credits). It’s been really easy to import and adapt them, and I’m surprised how fast this is coming along. This is my first game jam, and maybe I’ll finally publish my first game.

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#22

I made a change to the shadow_map.fp that fixes this for AMD and doubles the shadow distance for nVidia. Since it also works correctly on my iPhone without any change, I consider it an AMD driver bug.

I’ve never tried to work with shaders before, so I’m not sure that I understand fully what is going on here. I think it stores the distance to the occluder in a 1d texture. It gets this from the depth buffer bit. I doubled this distance before it is written to the shadow map, and that fixes it for AMD and breaks nVidia.

I’m hoping that gives someone that is interested some idea of how to work around this with AMD and still work with nVidia. I feel like it’s something with how AMD calculates the depth bit vs nVidia, but this is uneducated speculation on my part. Maybe there is some assumption in the shader program that works for nVidia but not the AMD drivers. Something with precision or clamping.

I would not even have noticed this if I wasn’t using my AMD card at the time… I feel it would be useful to fix this if it does affect all AMD cards and current drivers. Here is the change I made in a fork of this repo:

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