POV-Ray : Newsgroups : povray.binaries.images : Handbell : Re: Handbell Server Time
31 Jul 2024 14:26:29 EDT (-0400)
  Re: Handbell  
From: CShake
Date: 18 Aug 2009 00:55:57
Message: <4a8a345d$1@news.povray.org>
clipka wrote:
> Some ideas to try:
> 
> - As the bell's texture lives primarily from reflecting the light probe, 
> and nothing else does, blurring the probe instead of the texture surface 
> could to the trick.
Possible, but I'd like to make it possible to reuse the model in other 
places, so blurring the background is something I'll leave as a last option.

> - Add a bit of deformation to the bell, using pertubed normals (some 
> subtle bumps), to "break" the overly-ideal look of the bell.
I did that a bit on the inside (it's a slightly different finish/normal 
but the same pigment), but evidently not enough. I am content with the 
outside as-is, because a newly polished bell does look very close to 
that. I'm going to try to add 'rings' on the inside though, as evidence 
of the lathe tool used to shape the metal.

> - Use an averaged texture, with the major component as-is and another 
> one with significant micro normal pertubations, to simulate tiny 
> scratches in an otherwise well-polished surface.
I haven't played with averaged textures yet, seems like a good thing to 
look into.

> - Maybe add a coat-of-arms or something, etched into the outside of the 
> bell.
Not in the plan right now, but who knows.

> You should also do something to the belt, to break up the "sterility". 
> Some leather-like crackle normals (with an offset value) maybe.
It is supposed to be fairly smooth plastic, but it does need something.

> The clapper suffers from not having bevelled edges, maybe a cylindrical 
> shaft would do a lot better.
I'm trying for realism in the model here, and the shapes of everything 
are very close right now to what a real bell looks like. The shaft 
actually is a hexagon, though I could round over the edges of the 
clapper itself a little more.

>  > Minor focal blur,
>> radiosity with decreased brightness, and area light used.
> 
> I think it shows that you decreased radiosity brightness: It should be 
> stronger. I can't exactly pinpoint why, but maybe it's the way the bell 
> and the handle appear to be lit totally differently.
> 
> (just my $0.02)
I found that using rad brightness 1.0 made a huge bright glare on the 
side of the bell, which also suggests that there is too much reflection.
Another reason the lighting is a bit odd is that I added a spotlight a 
ways behind the camera to illuminate the inside, as increasing the 
ambient of the light probe made the whole thing glow. Gotta reduce that 
reflection I see now.

>  > I think the
>> line up the middle of the inside of the bell is a seam in the HDR 
>> probe (which is St.Peter's Basilica from Paul Debevec's gallery), I 
>> will rotate it once I have more changes to make.
> 
> Given the symmetry of that line, I'm pretty sure it's not in the light 
> probe, but the bell reflecting its own rim. Which in turn indicates that 
> the reflection is a bit too strong.
> 
> If you're using them right, the Devebec light probes are perfectly 
> seamless.
Right you are, I rotated the probe and got the same effect. I wasn't 
sure though, since I had to convert it to spherical mapping in HDRShop, 
as b33 doesn't support map_type 7.

Thanks for the input, I'll be working on it more.
For reference, this is the type of bell I'm trying to model: 
http://www.schulmerichbells.com/products_hb_anatomy_of_handbell.php

CShake


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