|
 |
before i ask my question, let me see if i have something straight:
height fields are converted into meshes, right? now, if this is so,
what happens to the ends and the bottom? are they closed off to get a
closed volume? i'm hoping they are. and if they are, can they be used
in CSG operations? that is the question i really want to know. i'm
thinking it would be cool to take one height field of a landscape, and
another of the opposite of a horizontal cave system, and them subtract
the caves from the landscape. or... if one could subtract various
shapes from a height field (like cylinders or cubes) to get caves that
way. can it be done?
Post a reply to this message
|
|
|
|
HF-s are not closed off per se, i.e. there is no 'lid' added to the bottom. But
unlike meshes, they do have a well defined interior and work predictably in CSG
constructs. Basically, everything below the HF-s surface is considered to be
inside it. So what you want to do is quite possible.
--
Margus Ramst
Personal e-mail: mar### [at] peak eduee
TAG (Team Assistance Group) e-mail: mar### [at] tagpovrayorg
Post a reply to this message
|
|
|
|
On Fri, 31 Mar 2000 16:32:11 -0800, ryan constantine
<rco### [at] yahoocom> wrote:
> before i ask my question, let me see if i have something straight:
> height fields are converted into meshes, right?
More or less. Yes, they are converted to meshes but use a hf-specific
hierarchical bounding scheme to speed them up.
> now, if this is so, what happens to the ends and the bottom? are
> they closed off to get a closed volume? i'm hoping they are.
Sorry, they are not. The bottom remains open.
> and if they are, can they be used in CSG operations?
Regardless, they can be used in CSG operations. There is a demo scene
in the standard distro called "hfclip.pov", I suggest you check it
out.
> that is the question i really want to know. i'm
> thinking it would be cool to take one height field of a landscape, and
>another of the opposite of a horizontal cave system, and them subtract
>the caves from the landscape. or... if one could subtract various
>shapes from a height field (like cylinders or cubes) to get caves that
>way. can it be done?
Frankly, yes, but you have to be careful with that horizontal hf. The
'volume' of the height_field lies below it, so if you make a hf you
want to use as a cutting object, make sure you point its bottom at the
object you're cutting from.
Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG e-mail : pet### [at] tagpovrayorg
Post a reply to this message
|
|
