I used PovRay for years. Learning how not to write PV code in OpenSCAD was
one of my biggest hurdles. I searched for something that could produce STL
files from PovRay code, for the sake of people who struggle with OpenSCAD’s
functional programming, but I didn’t find anything really workable.

On Thu, Feb 17, 2022 at 1:09 PM david vanhorn kc6ete@gmail.com wrote:

I WANT CLIPPING PLANES!!
Clipping things with boxes is very cumbersome.

I hear ya.  As an older embedded systems guy, my head is full of languages.
Snobol, Cobol, Lisp, Fortran, many flavors of Basic, Assembler for Z80, Z8,
6502, Pic, AVR, ARM..
We need a purge and defrag for the brain!

On Thu, Feb 17, 2022 at 12:29 PM Father Horton fatherhorton@gmail.com
wrote:

--
K1FZY (WA4TPW) SK  9/29/37-4/13/15

I don't want ANY code written my usoft running on MY brain...

Don't forget Forth!  (RPN calcs UNITE!)

I got nuthin.

On Thu, Feb 17, 2022 at 1:37 PM david vanhorn kc6ete@gmail.com wrote:

and Lithp! :)

On Thu, Feb 17, 2022 at 12:41 PM FF Systems joeh@rollanet.org wrote:

--
K1FZY (WA4TPW) SK  9/29/37-4/13/15

I have found this module really easy and intuitive to use. A tiny bit of work would add angle. I would do it using spherical coordinates rather than a rotate vector. I think it’s easier to picture.

-Bob
Tucson AZ

/*
crossSection(view)

Apply as a modifier operation.
Cuts the children on a plane.
Move the children around to modify the cut point.

view - View the cross section from this axis
"x" - Cut on the YZ plane - default
"y" - Cut on the XZ plane
"z" - Cut on the XY plane
*/

module crossSection(view = "x", right = 0, fwd = 0, up = 0) {
an = view == "x" ? LEFT
: view == "y" ? FRONT
: view == "z" ? BOTTOM
: view == "-x" ? RIGHT
: view == "-y" ? BACK
: view == "-z" ? TOP
: LEFT;

difference() {
    union() {
        children();
    }
    right(right)
    fwd(fwd)
    up(up)
    cube(1000, anchor = an);
}

}

On Feb 17, 2022, at 12:36, david vanhorn kc6ete@gmail.com wrote:

I WANT CLIPPING PLANES!!
Clipping things with boxes is very cumbersome.

I hear ya.  As an older embedded systems guy, my head is full of languages.
Snobol, Cobol, Lisp, Fortran, many flavors of Basic, Assembler for Z80, Z8, 6502, Pic, AVR, ARM..
We need a purge and defrag for the brain!

On Thu, Feb 17, 2022 at 12:29 PM Father Horton <fatherhorton@gmail.com mailto:fatherhorton@gmail.com> wrote:
I used PovRay for years. Learning how not to write PV code in OpenSCAD was one of my biggest hurdles. I searched for something that could produce STL files from PovRay code, for the sake of people who struggle with OpenSCAD’s functional programming, but I didn’t find anything really workable.

On Thu, Feb 17, 2022 at 1:09 PM david vanhorn <kc6ete@gmail.com mailto:kc6ete@gmail.com> wrote:
Interesting idea.  I wish OpenSCAD and PovRay talked to each other better.
I've used Povray to design a bunch of optical sensors over the years. VERY accurate.
In Pov I would put a BRIGHT light source out at an appropriate distance, and then I could "stick my head" in the baffle area which does NOT obstruct the light, and look at how much is falling on the sensor.
Then do an animation rotating from just inside the cutoff to just past the cutoff, and see how that looks on a white target at the sensor area.

On Thu, Feb 17, 2022 at 10:35 AM larry <lar3ry@sasktel.net mailto:lar3ry@sasktel.net> wrote:
On Wed, 2022-02-16 at 15:24 -0700, david vanhorn wrote:

Sure, but hey, you can design around that problem by offsetting the
opening. See picture

I think that depends on the size of the open volume, no?
If the cone is wider, then you can afford to block some of the light
with baffles of some sort.

What about this, referring to the attached picture?

It's just 2D to illustrate the idea. I leave the implementation and
dimensions up to you.

The narrow end of the cone is just large enough for the sensor, not the
whole device. The whole device sits in the light blue box.

The large end of the cone would be large enough so that the baffles
would create the field of view required.

I think the baffles would need to be designed carefully, in both
length and angle, so that light entering from the side, when reflecting
off the bottom of a baffle (referring to the orientation in the
picture), reflects into the area between each baffle and the one below
it.

You might need only one baffle, or perhaps more.

Anyway.. food for thought.

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--
K1FZY (WA4TPW) SK  9/29/37-4/13/15

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K1FZY (WA4TPW) SK  9/29/37-4/13/15

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Have you thought about what would happen if you made the baffle out of a
series of cubes with a decreasing width and length?
This would provide flat surfaces that would reflect incidental light
back out rather than funnel it in.

Would lining your existing baffle with black felt be just as effective?

I guess that you only have to reject enough light so that the sensor
only counts light that is sufficiently bright - ie a sufficiently large
number of photons make it through to the sensor.

On 2022-02-16 17:24, david vanhorn wrote:

--
Ron Wheeler
Artifact Software
438-345-3369
rwheeler@artifact-software.com