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#198 partial sphere drawn with model

v1.7.0
open-postponed
Chris Laurel
Core (65)
3
2008-09-16
2008-06-23
Selden Ball
No

When a builtin sphere is drawn adjacent to a mesh, only part of it is drawn from some viewpoints. It does not surround the model as it should. From other viewpoints, all of it is drawn, correctly partially enveloping the model.

An Addon demonstrating this problem is available at

http://www.lepp.cornell.edu/~seb/celestia/files/partial_sphere.zip
(4KB)

Discussion

  • Selden Ball
    Selden Ball
    2008-06-23

    image showing full and partial sphere being drawn

     
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  • Selden Ball
    Selden Ball
    2008-06-23

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    screengrab showing problem is attached.

     
  • Chris Laurel
    Chris Laurel
    2008-08-14

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    Spheres are intended to be used for planets and moons, so no provisions have been made to display them correctly from the inside. If you want geometry that surrounds a model, you should use a spherical mesh.

    I have plans to rewrite the planet renderer after 1.6.0 in order to greatly improve the level of detail (and fix depth sorting problems with buildings and other surface objects.) I can revisit this bug then, but my feeling is that we should just skip rendering anything when the viewer is inside a sphere.

     
  • Chris Laurel
    Chris Laurel
    2008-08-14

    • priority: 5 --> 3
    • status: open --> open-postponed
     
  • Selden Ball
    Selden Ball
    2008-08-14

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    Not rendering a builtin sphere when it is viewed from the inside is fine. It's actually useful when observing orbits and phases of satellites, for example.

    However, this reported problem is for a viewpoint which is *outside* the sphere, slightly above the plane of the intersecting CMOD Mesh object. The sphere should surround most of the object with just the ends of the "carpet" protruding.

    Even so, postponing a fix would be OK so far as I'm concerned.
    I discovered it while trying to define objects to be used as viewpoints and typed a larger radius than I had intended.

     
  • Chris Laurel
    Chris Laurel
    2008-08-14

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    If it's not showing up when the viewer is outside the sphere, that's a real problem. I'll keep this bug open and make sure that it gets fixed when I update the sphere rendering code.

     
  • Chris Laurel
    Chris Laurel
    2008-09-16

    • milestone: 779472 --> v1.7.0
     
  • Selden Ball
    Selden Ball
    2008-09-17

    Only part of the viewable hemisphere is drawn when the viewpoint is outside the sphere: that's the bug. But it can wait.