Going Off on a Tangent

Oh dear I appear to have gone off on tangent.

This had to be done at some point but I’ve been fiddling with shadows again. You see, there’s this annoying little jiggly effect that happens on the shadow edges of objects with sharp edges (like the building above).

There I was adding in the hotbar abilties to make a ranged magic attack and melee attack (being able to set the damage, check the range etc, add in a self heal/cure) when I decided to fix the annoying shadow problem.

There are huge volumes on real time shadow rendering and I can see why. After some more reading I tried various technique for getting rid or reducing the “shimmer/jiggle”. Most people seem to call it shimmering, mine looks more like a jiggle which I think should have been a clue.

Anyway I used a technique called Texel Snapping which I seemed to have used correctly and it made pretty much no difference. I contacted a couple of people on GameDev and various game development blog and no one could see anything wrong with my code. The ighty MJP from GameDev suggested the problem lies elsewhere (elsewhere to how I’m generating the shadow maps) and it seems he was right.

I found an old test problem I originally wrote to test my models in a little world with lighting and shadows and slung in my new “anti jiggle/shimmer” code. Boom! Perfect shadows. Even if I i deliberately stretch them out so they’re poor quality they still don’t jiggle or shimmer.

Well so where does that leave me. Amazing shadows in my game? No. Amazing shadows in my test harness and I’ve learned loads of techniques for making them soft etc using DX11. None of which fixes my Jiggle.

So now I have 2 versions of my lighting/shadow engine (both in Monogame – I had to convert the old test harness from XNA first). 1 jiggles, 1 doesn’t.

I need to find the difference. It’s there somewhere. My engine is kind of huge unfortunately.

Hopefully I’ll be back to actually writing the game again soon.

Another 2-3 weeks on shadows. Argh!