[BUG-7197] Request for new setting: EulerMode -180 to 180

sl-service-account commented 10 years ago

Traditionally, the buildtool displays rotations as numbers between 0 and 360 degrees. You can type a number outside of the 0 to 360 range, but as soon as the field loses focus, the number is wrapped in range 0 to 360. A circle is round, so the numbers -350, 10, 370 and 730 all represent the same angle, right?

The Y-rotation is a little strange, because of gimbal lock. Y only displays numbers in half of the circle: from 0 to 90, and from 270 to 360.

=======

This feature request is about a new optional setting to change the range from [0, 360] to [-180, 180]. As you can see, the range [-180, 180] makes a full circle, and the range is symmetrical around zero. This has a number of benefits:

12.3 and -12.3 represent the same angle, just in the opposite direction.
Y-rotation now displays numbers in the range [-90, 90].
Both gimbal lock thresholds have the same value, but one is negative.
The LSL function llRot2Euler() also uses the range [-180, 180].
The range [-180, 180] suffers less from floating point noise, so we get better accuracy.

The result is a more intuitive interface, in my opinion.

Original Jira Fields

| Field | Value | | ------------- | ------------- | | Issue | BUG-7197 | | Summary | Request for new setting: EulerMode -180 to 180 | | Type | New Feature Request | | Priority | Unset | | Status | Accepted | | Resolution | Accepted | | Reporter | Moon Metty (moon.metty) | | Created at | 2014-09-04T23:09:11Z | | Updated at | 2014-09-17T18:05:59Z | ``` { 'Business Unit': ['Platform'], 'Date of First Response': '2014-09-17T13:05:55.143-0500', 'How would you like the feature to work?': 'Traditionally, the buildtool displays rotations as numbers between 0 and 360 degrees. You can type a number outside of the 0 to 360 range, but as soon as the field loses focus, the number is wrapped in range 0 to 360. A circle is round, so the numbers -350, 10, 370 and 730 all represent the same angle, right?\r\n\r\nThe Y-rotation is a little strange, because of gimbal lock.\r\nY only displays numbers in half of the circle: from 0 to 90, and from 270 to 360.\r\n\r\n=======\r\n\r\nThis feature request is about a new optional setting to change the range from [0, 360] to [-180, 180].\r\nAs you can see, the range [-180, 180] makes a full circle, and the range is symmetrical around zero.\r\nThis has a number of benefits:\r\n\r\n- 12.3 and -12.3 represent the same angle, just in the opposite direction. \r\n- Y-rotation now displays numbers in the range [-90, 90].\r\n- Both gimbal lock thresholds have the same value, but one is negative.\r\n- The LSL function llRot2Euler() also uses the range [-180, 180].\r\n- The range [-180, 180] suffers less from floating point noise, so we get better accuracy.\r\n\r\nThe result is a more intuitive interface, in my opinion.', 'Target Viewer Version': 'viewer-development', 'Why is this feature important to you? How would it benefit the community?': '*', } ```

sl-service-account commented 10 years ago

Moon Metty commented at 2014-09-04T23:13:43Z, updated at 2014-09-04T23:15:15Z

Implementation of the basics turns out to be very easy. This functionality was needed for a recent bugtest. The new EulerMode simply worked first try, and without any sign of trouble.

First, add an entry to settings.xml:


    <key>EulerMode</key>
    <map>
      <key>Comment</key>
      <string>Disable:-180 to 180 Enable:0 to 360</string>
      <key>Persist</key>
      <integer>1</integer>
      <key>Type</key>
      <string>Boolean</string>
      <key>Value</key>
      <integer>1</integer>
    </map>

=======

Replace existing code in llpanelobject.cpp getstate():


    mCurEulerDegrees.mV[VX] = fmod(llround(mCurEulerDegrees.mV[VX], OBJECT_ROTATION_PRECISION) + 360.f, 360.f);
    mCurEulerDegrees.mV[VY] = fmod(llround(mCurEulerDegrees.mV[VY], OBJECT_ROTATION_PRECISION) + 360.f, 360.f);
    mCurEulerDegrees.mV[VZ] = fmod(llround(mCurEulerDegrees.mV[VZ], OBJECT_ROTATION_PRECISION) + 360.f, 360.f);

With new code:


    mCurEulerDegrees.mV[VX] = llround(mCurEulerDegrees.mV[VX], OBJECT_ROTATION_PRECISION);
    mCurEulerDegrees.mV[VY] = llround(mCurEulerDegrees.mV[VY], OBJECT_ROTATION_PRECISION);
    mCurEulerDegrees.mV[VZ] = llround(mCurEulerDegrees.mV[VZ], OBJECT_ROTATION_PRECISION);
    if (gSavedSettings.getBOOL("EulerMode"))
    {
        if (mCurEulerDegrees.mV[VX] < 0.f) mCurEulerDegrees.mV[VX] += 360.f;
        if (mCurEulerDegrees.mV[VY] < 0.f) mCurEulerDegrees.mV[VY] += 360.f;
        if (mCurEulerDegrees.mV[VZ] < 0.f) mCurEulerDegrees.mV[VZ] += 360.f;
    }

=======

Find existing code in lpanelobject.cpp sendRotation():


    new_rot.mV[VX] = llround(new_rot.mV[VX], OBJECT_ROTATION_PRECISION);
    new_rot.mV[VY] = llround(new_rot.mV[VY], OBJECT_ROTATION_PRECISION);
    new_rot.mV[VZ] = llround(new_rot.mV[VZ], OBJECT_ROTATION_PRECISION);

Add new code:


    new_rot.mV[VX] = llround(new_rot.mV[VX], OBJECT_ROTATION_PRECISION);
    new_rot.mV[VY] = llround(new_rot.mV[VY], OBJECT_ROTATION_PRECISION);
    new_rot.mV[VZ] = llround(new_rot.mV[VZ], OBJECT_ROTATION_PRECISION);
    if (gSavedSettings.getBOOL("EulerMode"))
    {
        if (new_rot.mV[VX] < 0.f) new_rot.mV[VX] += 360.f;
        if (new_rot.mV[VY] < 0.f) new_rot.mV[VY] += 360.f;
        if (new_rot.mV[VZ] < 0.f) new_rot.mV[VZ] += 360.f;
    }

=======

No more changes are needed to make the new EulerMode work. Of course there's no real user interface yet, apart form accessing the debugsettings, or editing settings.xml. Personally, I would probably always use the [-180, 180] range. However, the default setting should be [0, 360], because every tutorial uses this range. And some people could be allergic to negative numbers, you know?

sl-service-account commented 10 years ago

Marissa Linden commented at 2014-09-17T18:05:55Z

Thank you for your suggestion Moon Metty. We're importing this to our internal feature request queue.

secondlife / jira-archive

[BUG-7197] Request for new setting: EulerMode -180 to 180 #14937