William F Pokorny <ano### [at] anonymousorg> wrote:

Polygon as a df3 compression method.
Nice idea.

I'm not sure what this "offset" value is, but I'm wondering if there could be
some sort of z-axis control that allows one to make things analogous to the
prism's conic sweep.
And for that matter, I'm wondering if the prism can be worked into this whole
thing.

https://news.povray.org/povray.general/thread/%3Cweb.5d75c2d16af53e9cecc0fada0%40news.povray.org%3E/?mtop=431108

illustration:

https://news.povray.org/povray.binaries.images/thread/%3Cweb.5e97c744fd34edcfb0b41570%40news.povray.org%3E/?ttop=441730
&toff=400

> The upper right two images show the 'ip_type 0' potential pattern
> support which is a sort of infinite in z inside / outside test. The
> inside values being (1.0*('ip_offset value')). By wrapping these
> potential{} patterns in function{}s, this 'ip_type 0' is essentially a
> drawn drawn polygon-tiles and calk method. A numerically noise proof,
> and infinitely flexible alternative to the 'pavement' and 'tiling' value
> patterns, for example.

Not sure what I'm seeing there - is there a rotational offset?
Could the rotational offset be defined as rotation per unit, to get a spiraling
effect?
Maybe scratch whatever the "offset" currently is and incorporate a matrix
transform for greater flexibility?

> The bottom row of images show some of the kinds of potential patterns
> returned. The left most bottom being one of three possible
> bounding-box-based potential patterns.

That's definitely pretty cool - more explanation on what that's about, and show
the other two?

I see that the center point of the outer polygon is included in that diagram -
what if instead of drawing the even division of the AABB to give that "+", the
center point was "connected" to the vertices with rays, with the potential
varying in between the rays (to give an "X")
(or a star, like the macro I used here:
https://news.povray.org/web.54414d9ccbb3d8155e7df57c0%40news.povray.org)

> The remaining three images in the bottom row return polygon point
> values, connections between polygon points values and, on the very
> right, a stand-in 3D potential somewhat similar to the inbuilt
> f_rounded_box() function's value field - but defined by the polygon
> object's 2D shape.

One thing which could be cool, would be to re-order the connection points so
that they now skip every other point.  With odd-number polygons, one would get a
star.

Is there a way to easily achieve what is essentially a convex-hull effect -
where none of the inner sub-polygon points "count"?
Using the potential feature, one could then (potentially <--- Ha!) easily make
isosurfaces...


- BW

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