Add a tutorial teaching about lighting in Drake

This includes a number of resource files (illustrations, models, environment
maps, etc.) In addition, it includes the source files from which these
where generated (where reasonable).

TODO:
 - Add more illustrations (e.g., fitting shadow maps to scene.
 - Resolve file management

geometry/meshcat.html

@@ -158,7 +158,13 @@
         connection.onmessage = (msg) => handle_message(msg);
         connection.onopen = (evt) => {
           if (!accepting_connections) location.reload();
-          accepting_connections = false
+          accepting_connections = false;
+          // Immediately trigger the callback so that connection is sufficient
+          // to register a pose (otherwise, it doesn't happen until *something*
+          // else happens to trigger a render). Invoking the render callback is
+          // always safe because even if `tracked_camera` isn't enabled, the
+          // Viewer has a non-null no-op callback set.
+          viewer.render_callback();
         };
         connection.onclose = function(evt) {
           status_dom.style.display = "block";

tutorials/BUILD.bazel

@@ -3,6 +3,18 @@ load("//tools/jupyter:jupyter_py.bzl", "drake_jupyter_py_binary")
 load("//tools/lint:lint.bzl", "add_lint_tests")
 load("//tools/skylark:drake_py.bzl", "drake_py_test")
 
+filegroup(
+    name = "resources",
+    data = [
+        "resources/sphere.gltf",
+        "resources/sphere.bin",
+        "resources/env_color_room.png",
+        "resources/env_color_room_75.hdr",
+        "resources/env_color_room_150.hdr",
+        "resources/env_color_room_1200.hdr",
+    ],
+)
+
 drake_jupyter_py_binary(
     name = "authoring_leaf_systems",
     add_test_rule = 1,
@@ -19,6 +31,17 @@ drake_jupyter_py_binary(
     ],
 )
 
+drake_jupyter_py_binary(
+    name = "configuring_lighting",
+    add_test_rule = 1,
+    data = [
+        "resources",
+    ],
+    deps = [
+        "//bindings/pydrake",
+    ],
+)
+
 drake_jupyter_py_binary(
     name = "custom_gradients",
     add_test_rule = 1,