Tuesday, March 26, 2013

DAZzled By the Ray-Tracing

I've finished rigging my latest prop set and have started texturing.  This being Steampunk, the first task was to make a decent brass.

Of course there turns out to be a Dependency, in project-speak.  Metals are in part reflection, and in a virtual world, you need something there to be reflected.  Hence the need to create a reflection map.  Creating the map led me in turn back to stitching panoramas and playing with HDRI.

So I have a new find. Hugin, a free software application for the Mac.  It may not sit on Odin's shoulder, but it does give a nice view of the world.  Which is to say; it detects correspondences between pairs of images, applies lens models and perspective correction, estimates exposure correction, and does its best to stitch them all together into a seamless whole (which it can then export in spherical, cylindrical, and quite a few other mapping modes, as well as in either ordinary dynamic range or HDR).

It managed to do that trick on a half-dozen basically random hand-held pictures I'd taken from an observation tower over the gemültlich little hamlet of Bacharach-am-Rhein.  Call me impressed.  The options in HDRI are confusing and lack the direct feedback of software like, say, Light Compressor, but it appears to be assembling a legit .exr file from multiple sources.

But as it turned out, none of my photo collections include an actual panoramic sky (much less a period city-scape.)  So I spent a good chunk of the day assembling cloud photographs taken on several different days into a half-way believable 360' cyclorama.  My intention is to set up some props around a spherical camera and render that as a reflection map. 

Meanwhile, I've made a half-decent "new" brass in Poser 9, using one painted "dark wash" map and a random picture run through a spherize node.  The nodes and the basic behavior of Firefly are the same between Poser 6 (where I started the new material), and Poser 9.  Main difference is that, on the new computer, the test renders are much, much, much faster.  Enough where I'm not tearing out hairs trying to get through tweaking the values.

I also popped the test texture, and some rigged figures, into DAZStudio 4.5 to take a look at them there.  Which means I have a short review of that software as well.

Very pretty, menu options are a bit odd and not always intuitive, but in most cases feel quite decent after you get used to them.  One exception is finding the ERC channels, which always seems to take a bunch of tries.  Also, limits are apparently respected only for rotations, which means some bits of my rigging trickery don't work.  But almost every one of my tricky ERC dials did what they were supposed to and even the odd one out was totally acceptable.  And that's pretty good, considering I have multiple nested dials with negative values and hard limits running translates, rotations, and morphs on parts that also have PointAt on them!

The render engine is zippy fast.  So fast the first time, I was still waiting for the render window to pop up when I realized I was already looking at it.  This is in contrast to Poser, which even on my dual-core i7 takes a half-dozen seconds just to leave the Render view and return to Preview.

But the downside; although there are some nice technical options in the ray tracer, the materials nodes are extremely primitive.  Almost all of the fancy texturing of my previous prop set failed to work properly.  No noise channels at all.  No edge blend (which is essential for decent metals).  Actually, it is possible edge blend is being handled at some other level of the ray tracing, but even then it would be global, not node-based.  No decal or blending.  My drum sets have both a skin texture and a floating logo combined together in shader nodes.  DAZStudio's interpretation of that was to ignore all the texture maps and just put in the diffuse color (a very slight tint I was using for tonal adjustment).

Well, I knew this next prop set was going to be simpler in textures.  This just means I really do have to bake noise shaders and similar if I am going to have any real DAZ compatibility.

Oddly enough, though, the new brass texture didn't look bad.

I still have more work to create my new reflection map, and of course one of my favorite parts -- this is not meant ironically, for once -- of prop creation; painting up the texture maps!  I have various gauge faces and chipped metal and escutcheons filled with funny-sounding company names and slogans to make up.

But not right now.  I need to build a robot, and it needs to be ready by early tomorrow afternoon....when it will meet the little girl who is going to try her hand at programming it.

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