World grid part 2/2: Integrate into Viewer

[Wumpf]

Related

• Follow-up of part 1: World grid part 1/2: add world grid renderer to re_renderer #8230
• Fixes World-space grid #872

What

Adds new line grid property to the 3D view and enables it by default.

Feedback on variable & type names welcome needed!

Docs says it all:

/// Configuration for the 3D line grid.
table LineGrid3D (
    "attr.rerun.scope": "blueprint"
) {
    /// Whether the grid is visible.
    ///
    /// Defaults to true.
    visible: rerun.blueprint.components.Visible ("attr.rerun.component_optional", nullable, order: 1000);

    /// Space between grid lines spacing of one line to the next in scene units.
    spacing: rerun.blueprint.components.GridSpacing ("attr.rerun.component_optional", nullable, order: 2000);

    /// How the grid is oriented.
    ///
    /// Defaults to whatever plane is determined as the down plane by view coordinates if present.
    orientation: rerun.blueprint.components.PlaneOrientation ("attr.rerun.component_optional", nullable, order: 3000);

    /// Offset of the grid along its normal.
    offset: rerun.blueprint.components.PlaneOffset ("attr.rerun.component_optional", nullable, order: 4000);

    /// How thick the lines should be in ui units.
    ///
    /// Default is 0.5 ui unit.
    line_radius: rerun.blueprint.components.UiRadius ("attr.rerun.component_optional", nullable, order: 5000);

    /// Color used for the grid.
    ///
    /// Transparency via alpha channel is supported.
    /// Defaults to a slightly transparent light gray.
    color: rerun.components.Color ("attr.rerun.component_optional", nullable, order: 6000);
}

Properties in the viewer:

Examples of the grid in action (in default settings):

Bad case - it's below:

Changes to World grid renderer since original PR

• tweak when to fade - generally fade more aggressively to keep grid not as busy

Testing

• Metal
• Vulkan
• WebGPU
• WebGL

Draft TODO

• extend view creation python snippet with this property
  • check if python blueprint api is sane
• why is background showing as half transparent by default now?
• Adjust grid height for some samples or turn it off?
• try new idea for cardinal lines
• fix line thickness not working
• switch to plane equations for blueprint api -> provide extensions in all languages

[github-actions]

Latest documentation preview deployed successfully.

Result	Commit	Link
✅	6b18472	https://landing-cle5g2jqm-rerun.vercel.app/docs

^{Note: This comment is updated whenever you push a commit.}

[github-actions]

Web viewer built successfully. If applicable, you should also test it:

• I have tested the web viewer

Result	Commit	Link
✅	6b18472	https://rerun.io/viewer/pr/8234

^{Note: This comment is updated whenever you push a commit.}

[abey79]

The data model lgtm overall 👍🏻 The spacing is slightly ambiguous? Is that the small lines or big lines. For some reason, my (randomly picked) default mental model was that the spacing refers to the big lines, but looking at the screenshots it seems that it's for the small lines. Maybe just clarify that in the doc string.

And then we're good. (That is, until someone requests arbitrary sub-line count to cover for inch/feet/whatever.

[Wumpf]

thank you!

it's about the small lines. The big lines are right now a hardcoded visual gimmick to deal with zooming out, shows every 10th line
but yeah I can totally see where that confusion comes from!

[nikolausWest]

Small bug: it's now possible to set alpha in the color picker for the Lines3D override (which obviously doesn't work)