kindred/create
1
1
Fork 0
Code Issues 53 Pull Requests Actions Packages Projects 9 Releases 2 Wiki Activity

[PD] fix calculation of possible Helix intersections

Browse Source 
the current routine fails for the growth mode.

This PR fixes this by handling this case separately from the other modes.
This commit is contained in:
Uwe
2021-12-05 23:29:03 +01:00
parent a19f3787bd
commit 6efd5f1bf6
1 changed files with 43 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
src/Mod/PartDesign/App/FeatureHelix.cpp
View File

@@ -473,8 +473,29 @@ double Helix::safePitch()
{
Base::Vector3d axisVec = Axis.getValue();
Base::Vector3d startVec = axisVec.Cross(getProfileNormal()); // pointing towards the helix start point
if (startVec.IsNull())
return Precision::Confusion(); // if the axis orthogonal to the profile, any pitch > 0 is safe
HelixMode mode = static_cast<HelixMode>(Mode.getValue());
double growthValue = Growth.getValue();
double turnsValue = Turns.getValue();
// handle case if axis is orthogonal to profile
// since startVec.IsNull() fails sometimes, for e.g. (0.0, 0.0, -0.0)
// we take the precision into account
if (startVec.Length() < Precision::Confusion()) {
// when not in growth mode any pitch > 0 is safe
if (mode != HelixMode::height_turns_growth) {
return Precision::Confusion();
}
// if growth is not zero, there will in many cases be intersections
// when the turn is >= 1, thus return an 'infinite' pitch
// Note: The resulting helix body is in this case often garbage since
// the OCC algorithm to create the helix fails.
// Nevertheless, the result is a valid body so it should be valuable for users
// to get this correct warning anyway.
else {
if (abs(turnsValue) >= 1.0 && abs(growthValue) > 0.0)
return Precision::Infinite();
}
}
double angle = Angle.getValue() / 180.0 * M_PI;
gp_Dir direction(axisVec.x, axisVec.y, axisVec.z);
@@ -493,16 +514,27 @@ double Helix::safePitch()
// impossible to calculate it precisely. For example a circle has as bounding
// box a square and thus results in a larger pitch than really necessary
// minimal safe pitch if the angle is 0
double p0 = boundingBoxVec * direction;
// minimal safe pitch if the angle or growth is 0
double pitch0 = boundingBoxVec * direction;
// if the angle is so large that the distange perpendicular to p0
// between two turns is larger than the bounding box size in this direction
// the pitch can be smaller than p0
if (tan(abs(angle)) * p0 > abs(boundingBoxVec * directionStart))
return abs(boundingBoxVec * directionStart) / tan(abs(angle));
else
return p0;
if (mode == HelixMode::height_turns_growth) {
// if the distange perpendicular to axisVec
// between two turns is larger than the bounding box size in this direction
// the minimal necessary pitch is zero
if (abs(growthValue) > abs(boundingBoxVec * directionStart))
return 0.0;
else
return pitch0;
}
else {
// if the angle is so large that the distange perpendicular to axisVec
// between two turns is larger than the bounding box size in this direction
// the pitch can be smaller than pitch0
if (tan(abs(angle)) * pitch0 > abs(boundingBoxVec * directionStart))
return abs(boundingBoxVec * directionStart) / tan(abs(angle));
else
return pitch0;
}
}
// this function proposes pitch and height