Abhorsen
Render time: 00d00h0m00s

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I've finally returned to this hobby.

Construction
     The bells are spline lathes, the background is generated by the Project Tierra module
     The bells are textured by ... (drawn by ...).

Context
     Abhorsen trilogy by Garth Nix, also similar photoshopped image.
   

Production

Step 1: refamiliarise myself with POV-Ray. To just reacquaint myself with the coordinate system, I created a rough outline of a bell, to practise manipulating. Not the world's most exciting, but it showed me what I wanted to know.



Next step, check I can do the background I want - my POV-Ray skills aren't great enough to write the macros myself, but Project Tierra looks like it can come up with at least a rough approximation to what I want.

This is very low res, but it still took a yonk to render since it uses radiosity heavily.  I'd like to make my background the Clayr's Glacier, but I'm not sure I can tweak the settings that much - but if not I can still come up with a pretty good backdrop - especially if I can get a nighttime or dawn/dusk look.

Next, a little research on the rough proportions of hand bells. According to rough measurements of low res images on the internet, the handle length to bell length varies between 1:1 and 4:3. The length of the whole bell to the width of the fluted part (dunno what you call it) is about 2:1.
Roughly something like:

Not what I'd call highly polished, but enough for me to work on composition.

Wikipedia tells me that the bells range in size from the size of a pill box to that of a jar - at an approximation, this is between 5cm and 20 cm. This means the smallest bell is held in half a hand, the largest really ought to be held in two hands. In geometric progression (?) the linear ratio between two adjacent bells ought to be the 6th root of 4 ( ~ 1.259921050 ~ 1.26)
 

Spent quite some time working on a good way of doing the bells - came to the conclusion that the lathe object was best, so forced to work out splines - surprisingly easy, in concept at least. In practise, however ...




(orthographic projection)

But I'm making progress...

Using cubic splines instead of bezier splines halps smooth things out, and makes it all a bit more predictable, if less easy to control the gradients


(cubic_spline)

 
(Same lathe, but the repeated coordinates cut out so it smoothes off - ought to be possible to form the bell by plotting lots of coordinates - should work, if less elegant)

Since I need graph paper to get that many points, test rendered the same scene as before, using AA to see if the artifacts disappeared. 15 mins later:

Much better!

Made progress with the spline bell - the handle needs a better shape, metal fitments to join the bell and handle and at the end of the handle are required, the bell needs smoothing out, especially at the top (see pic), the wood texture needs refining and a great deal of general polishing is required, but it looks fairly good.


Tried a test render against the background - even without AA, the picture below required 2h22m26s - probably due to the reflections.  Must implement the 'bounded by' clause - might speed it up.  Managed to orient the bells to the random 'look at' direction using a transformation out of transforms.inc. The difference in size and the proportion of bells 'on screen' is due to the different screen res setting used by ProjectTierra (I think...). 

The obvious problem can hopefully be fixed by scaling the bells complex down.




The bells scaled by 0.05 and slightly reoriented (so they don't overlap) give the following (which, with the bells bounded_by, and with AA 0.3 took 18h50m20s! - the final composition will HURT! - esp. w/ radiosity)



The lathe surface flaws are very noticable, which needs fixing, and I need to remember to adjust the camera proportions.

Some experimentation that the fastest rendering is having each bell bounded_by a simple CSG cylinder - both unbounded and a merge of two cylinders is slower.  This may not scale up to a full scene - test?
Reading through Tierra.pov - got the 3:4 ratio built in, I hope.  Also worked out what gives with the scale - 1 unit ~ 1km - need to scale the bells down to reflect this (look up table above? - think c. 0.0001 to turn 1 unit to 1cm (??)). i_sky.inc might be easily adjustable to get moonlight - need to look into lightsys however.

Been thinking about adding charter marks as textures - material_maps seem to be the way to go.  Make the minor charter marks normal peturbations?  Or the bell mark a rough patch on the bell, and the minor marks gold instead of chrome?  Have been testing how to use material_map with the POV-Ray include image.


If you use cylindrical mapping, distortion in minimal even near the top of the bell.  The way to do underlying textures is to (rather than layer them) simply call them as the first texture definition.
Note: To keep the image in proportion, the source image needs an aspect ratio of 2π:1 (landscape).

Replacing the POV-Ray image with my own 'marks.bmp' (below) gives

 - texture { PinkAlabaster scale 1} texture { pigment { DMFDarkOak } scale 1} is actually rather pretty.  Note the distortion near the top (Fix: simply have the top part of the file scaled differently)



Colouring as originally intended, with Marks on the wood as well :

Encountered some problems working out the aspect ratio for the handle - once I actually stopped trying to take short cuts, found it was about 1:1, but there will be heavy distortion on the more complex handle I have planned.

Added in the major Mark (in this case, the mark that is probably going to be Astarael).  It is a normal peturbation based on bumps with a low magnitude and fine scale.

It needs fine tuning, and the material_map needs aligning better (that can wait until the bell shape is finalised - otherwise it is just pointless effort)

For a change of pace, moved the viewpoint of the viewer to 2 metres above ground level.  Something unknown caused the render time to explode to 3h25m25s though - probably a program running in the background.

If I don't mess around with the scene further, it will be important to use radiosity to clear out the black shadow a bit.



I just liked this one, for all it is accidental. 
#declare Bells =
merge{
object{ Bell translate <0,0,-0.00/2> scale 1.000000000 rotate <090,000,000> translate < 1.70*1.00, 0.0, 1.90*1.00> }
object{ Bell translate <0,0,-0.00/2> scale 1.259921050 rotate <090,000,000> translate < 1.70*1.26, 0.7, 1.90*1.26> }
object{ Bell translate <0,0,-0.00/2> scale 1.587401052 rotate <090,000,000> translate < 1.70*1.59, 1.4, 1.90*1.59> }
object{ Bell translate <0,0,-0.00/2> scale 2.000000000 rotate <090,000,000> translate < 1.70*2.00, 2.1, 1.90*2.00> }
object{ Bell translate <0,0,-0.00/2> scale 2.519842100 rotate <090,000,000> translate < 1.70*2.52, 2.7, 1.90*2.52> }
object{ Bell translate <0,0,-0.00/2> scale 3.174802104 rotate <090,000,000> translate < 1.70*3.17, 3.4, 1.90*3.17> }
object{ Bell translate <0,0,-0.00/2> scale 4.000000000 rotate <090,000,000> translate < 1.70*4.00, 4.2, 1.90*4.00> }
scale .005
rotate <0,90,0>
translate <-.019,0,.03>
} ;

Just to get an idea of what the scene will look like, I overlaid tierra.bmp with bells.bmp (the background being a white plane with ambient .1 NB: Interesting effect if you forget to comment the plane out of bells.pov and render tierra.pov)






Something odd happened with the camera here.  Tweaked it by changing the direction vector for the camera, which had odd knock on effects, but I'm happy with the composition - now need to render the bell into it's final form ('polish' the metal, and adjust the handle into a better shape), and play around with the landscape as well.




Have improved the metal part of the bell considerably by dropping the number of points in the spline by a factor of 4 (I seem to have neglected to save any images from this phase - see below).  Have also started work on the handle (work incomplete, esp. the end cap and near the bell).  Got quite a nice effect by giving the marks ambient 2 - but the gold is looking less suitable, perhaps - see if there is a fire-like texture.  Perhaps make the textured 'Major Mark' slightly ambient?  Or lose it altogether?


The above two pictures show both the refined handles and the effect of radiosity - the only difference between the two is that the bottom has radiosity enabled.

It looks pretty good with radiosity, and I've resolved to lose the 'Major Marks' - too much effort for little visual payoff, and it may even detract. With radiosity edges smooth together better, so the gold Marks look less unnatural (and also, not much luck with fire textures!) - need to adjust the ambient values a bit if using radiosity (they seem much brighter under this method)


5h8m26s























Abhorsen's line are dark haired and dark eyed, and their time in Death makes them prenaturally pale.
Perimeter gurds ch 2 p31
The wall: about 40ft high, and Crenellated
Charter Marks are not normally visible to ords.
The book of the dead: Pale green leather, tarnished silver clasps.
Abhorsen: Dark blue and silver keys.
Clayr are blond and dark skinned - wer white, plae blue and 7-pointed stars in gold
King is red and goldenn towers
Wallmaker is ?(green?) and silver trowels.