Creating texture maps, again

I'm wanting to create a Radiance texture and pattern for large,
light-colored pea gravel. Any thoughts on the best way to do this?

Randolph Fritz
Graduate Student
University of Oregon

Randolph Fritz wrote:

I'm wanting to create a Radiance texture and pattern for large,
light-colored pea gravel. Any thoughts on the best way to do this?

Um, convert a picture of the stuff to the radiance format
and apply it to your ground... Or did you have something
more elaborate in mind?

If you need to make sure that the reflectivity is correct,
then you can process the result with the normpat script,
which unfortunately is only available for unix systems.

If I remember correctly, then I've had mixed results with
the filtering functions in normpat, but that probable depends
on the characteristics of your picture. Maybe you can
process the original image with one of the common texture
editor programs around so that it tiles nicely. Most people
use those for creating background for their desktops or web
pages, but they serve equally well for this purpose.

-schorsch

···

--
Georg Mischler -- simulations developer -- schorsch at schorsch.com
+schorsch.com+ -- lighting design tools -- http://www.schorsch.com/

That would work for pattern but not texture, not so?

Randolph

···

On Wed, Mar 27, 2002 at 08:41:29PM -0500, Georg Mischler wrote:

Randolph Fritz wrote:

> I'm wanting to create a Radiance texture and pattern for large,
> light-colored pea gravel. Any thoughts on the best way to do this?

Um, convert a picture of the stuff to the radiance format
and apply it to your ground... Or did you have something
more elaborate in mind?

Randolph Fritz wrote:

> Randolph Fritz wrote:
>
> > I'm wanting to create a Radiance texture and pattern for large,
> > light-colored pea gravel. Any thoughts on the best way to do this?
>
>
> Um, convert a picture of the stuff to the radiance format
> and apply it to your ground... Or did you have something
> more elaborate in mind?
>

That would work for pattern but not texture, not so?

So you actually want a bump map for gravel?

I'm not sure how realistic that would end up. There's no
texpict modifier, so you'd have to go with data files.
But in general, textures work best for material structures
that have only limited deviation from the ideal surface.
The deep cavities in a gravel surface can't be modelled
realistically just by manipulating the normal vector.
At least I can't think of a good way to do so.

The other question is of course if you really need this
level of detail. If you keep your view points away from
the floor, then some kind of random noise might already
be enough to say "this is meant to be gravel". And a
pattern image goes a long way from there.

-schorsch

···

On Wed, Mar 27, 2002 at 08:41:29PM -0500, Georg Mischler wrote:

--
Georg Mischler -- simulations developer -- schorsch at schorsch.com
+schorsch.com+ -- lighting design tools -- http://www.schorsch.com/

Georg Mischler wrote:

Randolph Fritz wrote:

> > Randolph Fritz wrote:
> >
> > > I'm wanting to create a Radiance texture and pattern for large,
> > > light-colored pea gravel. Any thoughts on the best way to do this?
> >
> >
> > Um, convert a picture of the stuff to the radiance format
> > and apply it to your ground... Or did you have something
> > more elaborate in mind?
> >
>
> That would work for pattern but not texture, not so?

So you actually want a bump map for gravel?

I hacked together something to generate bump maps from texture images
(though not specifically for RADIANCE) simply based on the intensity
gradients. Pretty trivial, but looks good enuff. Unfortunately, the
source wound up somewhere in the Twilight Zone(tm). Hopefully I can dig
it up, but it's really not that difficult to write from scratch.

See ya!

···

> On Wed, Mar 27, 2002 at 08:41:29PM -0500, Georg Mischler wrote:

--
"Life is too short for core dumps"