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OpenSpace / OpenSpace

This is the official GitHub repository for OpenSpace: an open source astrovisualization project. For instructions on how to build and run OpenSpace, see the Getting Started Guides on the wiki page at http://docs.openspaceproject.com.
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Support Easier Tidal lock in FixedRotation #1740

Open micahnyc opened 3 years ago

micahnyc commented 3 years ago

An enhancement could be made to the FixedRotation to provide a tidally locked property, which could be a bool, if set, then the item is tidally locked to the parent node.

Alternatively the property could be an Identifier if it makes sense to have nodes tidally locked to things that are not their parent.

danrtell commented 3 years ago

for specifics on this issue: in exoplanet systems with high inclination (close to 90 degrees) fixed rotation appears to easily generate a gimbal lock that causes undesirable axial roll behavior when attempting to keep the axis fixed. Since planets don't inherit tilt from inclination there's probably something deeper to making this work easily. This would also have relevance for high inclination satellite models, like polar orbiters

alexanderbock commented 1 year ago

Creating a new TidalLockRotation that takes a host body that it is tidally locked towards

micahnyc commented 1 year ago

Bump from DMNS in slack: https://team-openspace.slack.com/archives/CCE4LH2P8/p1692736167679279

kachun-yu commented 1 year ago

Just joining the conversation now. Is there an example of FixedRotation that I can look at? I'm trying to understand what this property is and how it's used.

danrtell commented 1 year ago

We have some example exoplanets with it here https://www.dropbox.com/scl/fi/vrd28wsa19rluv9m0qkzv/exoplanets.zip?rlkey=nj16jlkpgd0fdgbc46wf3qoj6&dl=0 however we’ve never gotten it working fully correctly and the planets still end up with a roll perpendicular to their target.

alexanderbock commented 1 year ago

Other examples are the JWST band: https://github.com/OpenSpace/OpenSpace/blob/master/data/assets/scene/solarsystem/telescopes/jwst/jwst.asset#L37-L43

an alternative way to specify the Fixed Rotation is to give reference axes: https://github.com/OpenSpace/OpenSpace/blob/master/data/assets/scene/solarsystem/heliosphere/bastille_day/density_volume.asset#L24-L29