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[Mesh] Improve NASTRAN input support

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Adds support for original-NASTRAN fixed-field-width low-precision GRID
element (the existing code assumed space-delimited input).
This commit is contained in:
Chris Hennes
2021-09-22 11:11:59 -05:00
parent e233ba54e6
commit 7655e7347d
2 changed files with 89 additions and 27 deletions
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110
src/Mod/Mesh/App/Core/MeshIO.cpp
View File

@@ -148,6 +148,8 @@ std::vector<std::string> MeshInput::supportedMeshFormats()
fmt.emplace_back("stl");
fmt.emplace_back("ast");
fmt.emplace_back("obj");
fmt.emplace_back("nas");
fmt.emplace_back("bdf");
fmt.emplace_back("off");
fmt.emplace_back("smf");
return fmt;
@@ -1636,10 +1638,6 @@ bool MeshInput::LoadNastran (std::istream &rstrIn)
if ((!rstrIn) || (rstrIn.bad() == true))
return false;
boost::regex rx_p("\\s*GRID\\s+([0-9]+)"
"\\s+([-+]?[0-9]*)\\.?([0-9]+([eE][-+]?[0-9]+)?)"
"\\s+([-+]?[0-9]*)\\.?([0-9]+([eE][-+]?[0-9]+)?)"
"\\s+([-+]?[0-9]*)\\.?([0-9]+([eE][-+]?[0-9]+)?)\\s*");
boost::regex rx_t("\\s*CTRIA3\\s+([0-9]+)\\s+([0-9]+)"
"\\s+([0-9]+)\\s+([0-9]+)\\s+([0-9]+)\\s*");
boost::regex rx_q("\\s*CQUAD4\\s+([0-9]+)\\s+([0-9]+)"
@@ -1656,6 +1654,8 @@ bool MeshInput::LoadNastran (std::istream &rstrIn)
std::map <int, TRIA> mTria;
std::map <int, QUAD> mQuad;
int badElementCounter = 0;
while (std::getline(rstrIn, line)) {
upper(ltrim(line));
if (line.empty()) {
@@ -1664,22 +1664,24 @@ bool MeshInput::LoadNastran (std::istream &rstrIn)
else if (line.rfind("GRID*", 0) == 0) {
// This element is the 16-digit-precision GRID element, which occupies two lines of the card. Note that
// FreeCAD discards the extra precision, downcasting to an four-byte float.
//
// The two lines are:
// 1 8 24 40 56
// GRID* Index(16) Blank(16) x(16) y(at least one)
// * z(at least one)
//
// The first character is typically the sign, and may be omitted for positive numbers,
// so it is possible for a field to begin with a blank. Trailing zeros may be omitted, so
// a field may also end with blanks. No space or other delimiter is required between
// the numbers. The following is a valid NASTRAN GRID* element:
//
// GRID* 1 0.1234567890120.
// * 1.
//
if (line.length() < 8 + 16 + 16 + 16 + 1) // Element type(8), index(16), empty(16), x(16), y(>=1)
//
// The two lines are:
// 1 8 24 40 56
// GRID* Index(16) Blank(16) x(16) y(at least one)
// * z(at least one)
//
// The first character is typically the sign, and may be omitted for positive numbers,
// so it is possible for a field to begin with a blank. Trailing zeros may be omitted, so
// a field may also end with blanks. No space or other delimiter is required between
// the numbers. The following is a valid NASTRAN GRID* element:
//
// GRID* 1 0.1234567890120.
// * 1.
//
if (line.length() < 8 + 16 + 16 + 16 + 1) { // Element type(8), index(16), empty(16), x(16), y(>=1)
badElementCounter++;
continue;
}
auto indexView = std::string_view(&line[8], 16);
auto blankView = std::string_view(&line[8+16], 16);
auto xView = std::string_view(&line[8+16+16], 16);
@@ -1688,8 +1690,10 @@ bool MeshInput::LoadNastran (std::istream &rstrIn)
std::string line2;
std::getline(rstrIn, line2);
if ((!line2.empty() && line2[0] != '*') ||
line2.length() < 9)
line2.length() < 9) {
badElementCounter++;
continue; // File format error: second line is not a continuation line
}
auto zView = std::string_view(&line2[8]);
// We have to strip off any whitespace (technically really just any *trailing* whitespace):
@@ -1700,19 +1704,23 @@ bool MeshInput::LoadNastran (std::istream &rstrIn)
auto converter = boost::cnv::spirit();
auto indexCheck = boost::convert<int>(indexString, converter);
if (!indexCheck.is_initialized())
if (!indexCheck.is_initialized()) {
// File format error: index couldn't be converted to an integer
badElementCounter++;
continue;
index = indexCheck.get();
}
index = indexCheck.get() - 1; // Minus one so we are zero-indexed to match existing code
// Get the high-precision versions first
auto x = boost::convert<double>(xString, converter);
auto y = boost::convert<double>(yString, converter);
auto z = boost::convert<double>(zString, converter);
if (!x.is_initialized() || !y.is_initialized() || !z.is_initialized())
if (!x.is_initialized() || !y.is_initialized() || !z.is_initialized()) {
// File format error: x, y or z could not be converted
badElementCounter++;
continue;
}
// Now drop precision:
mNode[index].x = (float)x.get();
@@ -1720,13 +1728,63 @@ bool MeshInput::LoadNastran (std::istream &rstrIn)
mNode[index].z = (float)z.get();
}
else if (line.rfind("GRID", 0) == 0) {
if (boost::regex_match(line.c_str(), what, rx_p)) {
boost::regex rx_spaceDelimited("\\s*GRID\\s+([0-9]+)"
"\\s+([-+]?[0-9]*)\\.?([0-9]+([eE][-+]?[0-9]+)?)"
"\\s+([-+]?[0-9]*)\\.?([0-9]+([eE][-+]?[0-9]+)?)"
"\\s+([-+]?[0-9]*)\\.?([0-9]+([eE][-+]?[0-9]+)?)\\s*");
if (boost::regex_match(line.c_str(), what, rx_spaceDelimited)) {
// insert the read-in vertex into a map to preserve the order
index = std::atol(what[1].first)-1;
mNode[index].x = (float)std::atof(what[2].first);
mNode[index].y = (float)std::atof(what[5].first);
mNode[index].z = (float)std::atof(what[8].first);
}
else {
// Classic NASTRAN uses a fixed 8 character field width:
// 1 8 16 24 32 40
// $-------ID------CP------X1------X2------X3------CD------PS------9-------+-------
// GRID 1 1.2345671.2345671.234567
// GRID 112 6.0000000.5000000.00E+00
if (line.length() < 41) { // Element type(8), id(8), cp(8), x(8), y(8), z(at least 1)
badElementCounter++;
continue;
}
auto indexView = std::string_view(&line[8], 8);
auto xView = std::string_view(&line[24], 8);
auto yView = std::string_view(&line[32], 8);
auto zView = std::string_view(&line[40], 8);
auto indexString = boost::trim_copy(std::string(indexView));
auto xString = boost::trim_copy(std::string(xView));
auto yString = boost::trim_copy(std::string(yView));
auto zString = boost::trim_copy(std::string(zView));
auto converter = boost::cnv::spirit();
auto indexCheck = boost::convert<int>(indexString, converter);
if (!indexCheck.is_initialized()) {
// File format error: index couldn't be converted to an integer
badElementCounter++;
continue;
}
index = indexCheck.get() - 1; // Minus one so we are zero-indexed to match existing code
auto x = boost::convert<float>(xString, converter);
auto y = boost::convert<float>(yString, converter);
auto z = boost::convert<float>(zString, converter);
if (!x.is_initialized() || !y.is_initialized() || !z.is_initialized()) {
// File format error: x, y or z could not be converted
badElementCounter++;
continue;
}
mNode[index].x = x.get();
mNode[index].y = y.get();
mNode[index].z = z.get();
}
}
else if (line.rfind("CTRIA3 ", 0) == 0) {
if (boost::regex_match(line.c_str(), what, rx_t)) {
@@ -1749,6 +1807,10 @@ bool MeshInput::LoadNastran (std::istream &rstrIn)
}
}
if (badElementCounter > 0) {
Base::Console().Warning("Found bad elements while reading NASTRAN file.");
}
float fLength[2];
if (mTria.empty())
index = 0;

6
src/Mod/Mesh/Gui/Command.cpp
View File

@@ -449,15 +449,15 @@ void CmdMeshImport::activated(int)
{
// use current path as default
QStringList filter;
filter << QString::fromLatin1("%1 (*.stl *.ast *.bms *.obj *.off *.ply)").arg(QObject::tr("All Mesh Files"));
filter << QString::fromLatin1("%1 (*.stl *.ast *.bms *.obj *.off *.iv *.ply *.nas *.bdf)").arg(QObject::tr("All Mesh Files"));
filter << QString::fromLatin1("%1 (*.stl)").arg(QObject::tr("Binary STL"));
filter << QString::fromLatin1("%1 (*.ast)").arg(QObject::tr("ASCII STL"));
filter << QString::fromLatin1("%1 (*.bms)").arg(QObject::tr("Binary Mesh"));
filter << QString::fromLatin1("%1 (*.obj)").arg(QObject::tr("Alias Mesh"));
filter << QString::fromLatin1("%1 (*.off)").arg(QObject::tr("Object File Format"));
filter << QString::fromLatin1("%1 (*.iv)").arg(QObject::tr("Inventor V2.1 ascii"));
filter << QString::fromLatin1("%1 (*.iv)").arg(QObject::tr("Inventor V2.1 ASCII"));
filter << QString::fromLatin1("%1 (*.ply)").arg(QObject::tr("Stanford Polygon"));
//filter << "Nastran (*.nas *.bdf)";
filter << QString::fromLatin1("%1 (*.nas *.bdf)").arg(QObject::tr("NASTRAN"));
filter << QString::fromLatin1("%1 (*.*)").arg(QObject::tr("All Files"));
// Allow multi selection