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New Browser-based CAD System is Best Friends With Triangle Meshes

Who’s interested in a brand new, from-scratch boundary representation (BREP) kernel? How about one that has no topological naming problem, a web-native parametric CAD front end to play with, and has CAD-type operations making friends with triangle meshes? If you’re intrigued, check out [mmiscool]’s BREP project.

Functioning (let alone feature-filled, or efficient) CAD systems are not a software project we see a whole lot of. Ones that represent models as genuine BREP structures but cleverly use mesh-based operations where it makes sense? Even less so.

In theory, CAD programs are simple: allow a user to define features, keep track of what they are and how they relate to one another, and perform operations on them as requested. In practice, it’s significant work. Chains of operations and dependencies easily become complex, volatile things and there is really no room for error.

Read [Arya Voronova]’s best practices for using FreeCAD to get a few hints as to what goes on behind the scenes in a modern CAD program, and the kinds of challenges the back end has to deal with, like the topological naming problem (TNP). A problem [mmiscool]’s implementation completely avoids, by the way.

There is a live demo at BREP.io which acts as a playground for the state of the project. You can get started by clicking the + button towards the top on the left panel to add features and operations to the history (like add a cube, then add chamfers or fillets, or extrude a face, and so on).

[mmiscool] points out that all computation is done client-side; even complex operations like fillets, lofts, and multi-body booleans execute directly in the browser with no need to be offloaded to a back end. BREP’s development is being documented on Hackaday.io and there is a video embedded below that gives an overview. Why don’t you give it a spin?

MicroCAD Programs CAD

We love and hate OpenSCAD. As programmers, we like describing objects we want to 3D print or otherwise model. As programmers, we hate all the strange things about OpenSCAD that make it not like a normal programming language. Maybe µCAD (or Microcad) is the answer. This new entry in the field lets you build things programmatically and is written in Rust.

In fact, the only way to get it right now is to build it from source using cargo. Assuming you already have Rust, that’s not hard. Simply enter: cargo install microcad. If you don’t already have Rust, well, then that’s a problem. However, we did try to build it, and despite having the native library libmanifold available, Rust couldn’t find it. You might have better luck.

You can get a feel for the language by going through one of the tutorials, like the one for building a LEGO-like shape. Here’s a bit of code from that tutorial:


use std::geo2d::*;
use std::ops::*;

const SPACING = 8mm;

op grid(columns: Integer, rows: Integer) {
@input
.translate(x = [1..columns] * SPACING, y = [1..rows] * SPACING)
.align()
}

sketch Base(
columns: Integer,
rows: Integer,
width: Length,
height: Length
) {
thickness = 1.2mm;
frame = Frame(width, height, thickness);
struts = Ring(outer_d = 6.51mm, inner_d = 4.8mm)
.grid(columns = columns-1, rows = rows-1);
frame | struts;
}

There are proper functions, support for 2D sketches and 3D objects, and even a VSCode extension.

Will you try it? If we can get it to build, we will. Meanwhile, there’s always OpenSCAD. Even TinkerCAD can do some parametric modeling.

Threat Modeling in Modern Security Programs

By: hoek

I created this based on various internet sources for a company that is planning to carry out threat modelling. It is a general outline and preliminary proposal that you can adapt to your needs. Hopefully someone will find it useful.

Experts in this field may be able to provide more information, but it seems to me that this is not yet a

NASA Flights Study Cosmic Ray Effects for Air, Future Space Travelers

4 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

Recent airborne science flights to Greenland are improving NASA’s understanding of space weather by measuring radiation exposure to air travelers and validating global radiation maps used in flight path planning. This unique data also has value beyond the Earth as a celestial roadmap for using the same instrumentation to monitor radiation levels for travelers entering Mars’ atmosphere and for upcoming lunar exploration.

NASA’s Space Weather Aviation Radiation (SWXRAD) aircraft flight campaign took place August 25-28 and conducted two five-hour flights in Nuuk, Greenland. Based out of NASA’s Langley Research Center in Hampton, Virginia, the mission gathered dosimetry measurements, or the radiation dose level, to air travelers from cosmic radiation. Cosmic radiation is caused by high-energy particles from outer space that originate from our Sun during eruptive events like solar flares and from events farther away, like supernovae in our Milky Way galaxy and beyond.

Photo shows two researchers sitting in the back of an aircraft working on laptops and reviewing incoming data. The image composition shows the round cabin shape and rows of round windows on either side of the aircraft with light coming in during a flight.
Science team partners from Honeywell reviewing dosimeter data on board NASA’s B200 King Air during a flight over Nuuk, Greenland.
NASA/Guillaume Gronoff

“With NASA spacecraft and astronauts exploring the Moon, Mars, and beyond, we support critical research to understand – and ultimately predict – the impacts of space weather across the solar system,” said Jamie Favors, director of NASA’s Space Weather Program at NASA Headquarters in Washington. “Though this project is focused on aviation applications on Earth, NAIRAS could be part of the next generation of tools supporting Artemis missions to the Moon and eventually human missions to Mars.”

Two heliophysics researchers are seen in the doorway of NASA's B200 King Air aircraft holding and discussing a dol
Jamie Favors, NASA Space Weather Program director, and Chris Mertens, SWXRAD principal investigator, discussing a dosimeter at NASA’s Langley Research Center as specialized instruments are integrated onto NASA’s B200 King Air aircraft before deploying to Greenland.
NASA/Mark Knopp

NASA’s Nowcast of Aerospace Ionizing Radiation System, or NAIRAS, is the modeling system being enhanced by the SWXRAD airborne science flights. The model features real-time global maps of the hazardous radiation in the atmosphere and creates exposure predictions for aircraft and spacecraft.

NASA’s B200 King Air on the runway in Goose Bay, Canada, a stop during the flight to Nuuk, Greenland.
NASA/Guillaume Gronoff

“The radiation exposure is maximum at the poles and minimum at the equator because of the effect of Earth’s magnetic field. In the polar regions, the magnetic field lines are directed into or out of the Earth, so there’s no deflection or shielding by the fields of the radiation environment that you see everywhere else.” explained Chris Mertens, principal investigator of SWXRAD at NASA Langley. “Greenland is a region where the shielding of cosmic radiation by Earth’s magnetic field is zero.”

That means flight crews and travelers on polar flights from the U.S. to Asia or from the U.S. to Europe are exposed to higher levels of radiation.

Frozen and rocky terrain in the Polar region observed from above Nuuk, Greenland during NASA’s SWXRAD science flights.
NASA/Guillaume Gronoff

The data gathered in Greenland will be compared to the NAIRAS modeling, which bases its computation on sources around the globe that include neutron monitors and instruments that measure solar wind parameters and the magnetic field along with spaceborne data from instruments like the NOAA GOES series of satellites.

“If the new data doesn’t agree, we have to go back and look at why that is,” said Mertens. “In the radiation environment, one of the biggest uncertainties is the effect of Earth’s magnetic field. So, this mission eliminates that variable in the model and enables us to concentrate on other areas, like characterizing the particles that are coming in from space into the atmosphere, and then the transport and interactions with the atmosphere.”

An aerial view of Nuuk, Greenland. Blue skies with white clouds are in the top of the frame. Mountains and villages and buildings are in the center with dark blue water seen at the bottom portion of the image.
An aerial view of Nuuk, Greenland.
NASA/Guillaume Gronoff

The SWXRAD science team flew aboard NASA’s B200 King Air with five researchers and crew members. In the coming months, the team will focus on measurement data quality checks, quantitative modeling comparisons, and a validation study between current NAIRAS data and the new aircraft dosimeter measurements.

All of this information is endeavoring to protect pilots and passengers on Earth from the health risks associated with radiation exposure while using NASA’s existing science capabilities to safely bring astronauts to the Moon and Mars.

Northern Lights, or auroras, seen over the city of Nuuk, Greenland. Auroras are considered space weather and are easily visible effects of activity from the Sun interacting with the magnetosphere and Earth’s atmosphere.
NASA/Guillaume Gronoff

“Once you get to Mars and even the transit out to Mars, there would be times where we don’t have any data sets to really understand what the environment is out there,” said Favors. “So we’re starting to think about not only how do we get ready for those humans on Mars, but also what data do we need to bring with them? So we’re feeding this data into models exactly like NAIRAS. This model is thinking about Mars in the same way it’s thinking about Earth.”

The SWXRAD flight mission is funded through NASA’s Science Mission Directorate Heliophysics Division. NASA’s Space Weather Program Office is hosted at NASA Langley and facilitates researchers in the creation of new tools to predict space weather and to understand space weather effects on Earth’s infrastructure, technology, and society.

For more information on NASA Heliophysics and NAIRAS modeling visit:

NASA Space Weather

NASA’s Nowcast of Aerospace Ionizing Radiation System

About the Author

Charles G. Hatfield

Charles G. Hatfield

Science Public Affairs Officer, NASA Langley Research Center

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