Tim Nikias nous apporta ses lumieres en ce 10/11/2006 13:21:
> I've got a fairly elaborate problem in my project that I'm working on 
> with a couple of co-students at the university. We're digitally 
> reconstructing a castle and have a few towers with cone-tipped roofs or 
> even onion-shaped (looking much like those arabic and/or indian 
> tower-roofs)...

> Anyways, I've got a rectangular, tileable slate roof texture, and my 
> idea was to create a bunch of single shingles, map them onto prisms or 
> triangles/quads, and write a script which'll follow the shape of the 
> roofs, place an appropriate amount of shingles based on the 
> circumferance, move on to the next row... Until the roof is finished. 
> I'd then render a top-view of the result and project that back onto the 
> original cone.
Why that extra step? Your script can place your individual shingles/tiles 
directly onto your roofs.

> This will work fine for those towers that actually have a cone as a 
> roof, those that have onions will have a projection problem on places 
> where the roof is nearly vertical. I began wondering if it might be 
> possible to render a cylindrical view of the towers, but not from the 
> inside out, instead, from the outside (a certain distance) towards the 
> center. I thus would get a cylindrical texture I can map back onto the 
> onion shape with little less stretching issues...

> Anyone have a clue about how I might achieve that with POV-Ray (just 
> rendering that cylindrical view, everything else I can pretty much 
> script myself)? I'm dimly remembering that there was once a patched 
> POV-Ray which would allow functions as input for the camera, I'm 
> wondering if I'd need that (and if anyone has a suitable function 
> already at hand, I'm not that good with those)...

> Regards,
> Tim

> PS: Just re-reading this post for errors and misspelling, I was 
> wondering if I could use the basic cylindrical rendering POV-Ray 
> provides, but simply switch the roof-tiles to no_image, place a 
> reflecting cylinder outside the roof, and thus, render the reflection 
> *as if* I was looking from the outside... Hm, worth a shot, at least...

Did you try cylindrical warp? spherical warp?
You also can use trace to place your tiles on the conical and onion shaped roofs 
  and do away with texture maping.

-- 
Alain
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Don't take life too seriously, you won't get out alive.

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