Transparent Materials

All the changes I have been making under the hood have started to bear fruit. Aside from the layer mask support in shadows I mentioned earlier, beams and billboards support shadows and transparency, now. And ordinary meshes can be made transparent, including ones with layered materials, just by setting an opacity. (Although, with layered materials I also need to make sure not to layer any properties, like gloss or metallic, that are not supported in the transparent shader.)

The resolution of transparent objects is reduced, and shadows for transparent materials are... a bit ugly. But what can you do? This is almost ten-year-old technology I'm working with. It's still pretty neat.

Holey Title, Batman

I have been busily rewriting the entire shader definition system to be more flexible and converting all the existing shaders over to the new system. The end result of all this is... nothing changes.

That's not exactly true. Some new features come out of this, just because a new framework makes them easier to implement. For example, masks selected by a layer selection texture can now cast shadows. There are also a lot less classes and clutter around shadow shaders in general, but that's more difficult to illustrate with an image.

Text Too

I built a framework for cacheing letters, and a bunch of code for getting the positions of individual letters in a typeset string from the OS-level text rendering library (Core Text in OSX). And then I wrote a shader that can be called as something like a particle system, picking out the appropriate character data, placing the quad to render that character, getting the cached texture data for that character and drawing it to the screen.

After that, I refactored the character animation code to use what I had learned about buffer textures, eliminating the limits on joints (skeletal animation, mentioned here but implemented before I restarted this blog, some YouTube posts here and here) and shape keys (see this post), and saving a bunch of memory by compacting shape keys to only store data for vertexes that have useful data. It's all pretty cool but has absolutely no visible effect on the final product. Woo.

Today, I made improvements to the screen-space reflection shader (first implemented two years ago) I had been meaning to make for a long time, which means I'm getting close to the point where I can't avoid working on something new.

Text

So, more fooling around on things which aren't what I was going to fool around with. I need text for debugging, among other things, so I decided I would "get that out of the way." Turns out, it's a little bit more complicated than that.

But, after some work, I have it more-or-less working. Well, a start of it. One part was just getting characters rendered onto textures. Then, of course, I had to start working on distance fields, because all the kids are talking about distance fields these days. The screen shot below might illustrate why.

The two words are rendered using textures of the same size (about 32 pixels high in total). The top one is anti-aliased text, and the bottom is a distance field. The distance field is generated from anti-aliased text at four times the resolution, and then scaled down. As you can probably see, this produces a nice clear shape even at the relatively low resolution of the final texture. Generating distance fields from anti-aliased text, caching font info, getting text and distance fields added to my material definition formats, that all took a bunch of time.

And I still have to get this text stuff into the UI.

LODs and Skeletons

This figure is familiar from my earlier implementation of skeletal animations, if anyone was actually reading any of this so that they could actually be familiar with it. It's familiar to me, anyway.

The blue man group member has been washed to reveal an almost flesh-colored putty person. But there's a secret here. This isn't the same model as before, but one I've added a simplified LOD mesh to (in Blender 2.80, by the way, which seems a lot easier to use than 2.79, highly recommended). LOD scales are exaggerated, as usual, so you can see the switch as I move the camera around. The cool thing is that the skeletal animation attached to the original (base) model is automatically hooked up so that it works with other levels of detail. This might sound obvious, but, of course, it takes effort to make things that should work actually work for real.

Next, to check that it also works with shape keys (already implemented, but that just means the bugs are all in place).

Loads of LODs

Finally back to doing stuff. Another pile of work went in to doing this thing which should normally be invisible.

In the previous post I showed some automatic LOD generation, which is OK I guess, but doesn't do a great job all the time. For more control, you need to be able to import multiple versions of the same mesh which you have built by hand. The cylinder above is actually three separate objects which were created in Blender and imported from one file. The scales for switching between LODs were assigned automatically (based on the size of the faces in the objects), and are exaggerated here, again, for debugging.

So, that's working. Now just to check it works in concert with some other features, and then I can move on to... other things.