Support HDR (.hdr) images as environment maps

[SeanCurtis-TRI]

• Added loader for hdr images.
  • Added "Render Settings" control with "exposure" so the final rendering can be better controlled.
  • Added a hard-coded tone mapper. We can consider exposing it in render settings in the future if we like.
  • Normalized color environment maps (e.g. png) have been tweaked so the background image is affected by the exposure setting.
• Fixed redraw related bugs
  • Changing the background image/state would lead to a single rendering in which the lighting was incorrect. This was a due to a synchronization error between the rendering system and the image loading.
• test/background.html exercises all features.
  • the glTF cube has been replaced with a sphere to better showcase the environment maps.
  • The environment maps are now external images (rather than data urls in the html).

Related to RobotLocomotion/drake#20366

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This change is 

[SeanCurtis-TRI]

+a:@jwnimmer-tri for review, please.

[jwnimmer-tri]

@jwnimmer-tri reviewed 6 of 6 files at r1, all commit messages.
Reviewable status: all files reviewed, 6 unresolved discussions (waiting on @SeanCurtis-TRI)

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src/index.js line 371 at r1 (raw file):

        // setting a value will automatically trigger a re-render. When we call
        // set_property() on the containing SceneNode, we need to trigger a
        // rerender. SceneNode.set_property() calls this function, to indicate

typo (consistency)

Suggestion:

re-render.

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src/index.js line 1131 at r1 (raw file):

    const extension = path.slice((path.lastIndexOf('.') - 1 >>> 0) + 2);
    let texture = null;
    switch (extension.toLowerCase()) {

The path here is... a URL? I don't think we can trust that URLs end with human extensions. The drake::geometry::Meshcat CAS cache doesn't set the extention, does it? Only the mime type.

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src/index.js line 1391 at r1 (raw file):

        this.update_background();

        this.set_object(["Render Settings"], new RenderConfig());

This causes a console error message.

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test/background.html line 30 at r1 (raw file):

            // use_hdr defaults to false; so env map defaults to png.
            let env_map = env_map_png;
            

nit Trailing whitespace.

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test/background.html line 52 at r1 (raw file):

                    }],
                    materials: [
                        { 

nit Trailing whitespace

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test/background.html line 135 at r1 (raw file):

                        regardless of camera projection type or definition of \
                        an environment map. The white field still serves as \
                        environment map, so the box should be brightly lit."

typo

Suggestion:

sphere

[jwnimmer-tri]

Reviewable status: all files reviewed, 6 unresolved discussions (waiting on @SeanCurtis-TRI)

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src/index.js line 1131 at r1 (raw file):

Previously, jwnimmer-tri (Jeremy Nimmer) wrote…

The path here is... a URL? I don't think we can trust that URLs end with human extensions. The drake::geometry::Meshcat CAS cache doesn't set the extention, does it? Only the mime type.

(Also if its a URL it could have ? or # trailing the filename extension, I think.)