Add plugin updaters to playground examples.

playground/src/jvmMain/kotlin/randomSpheres.kt

@@ -34,7 +34,7 @@ fun main() {
         }
     }
 
-    VisionForge.makeVisionFile(
+    VisionForge.withSolids().makeVisionFile(
         fragment,
         Paths.get("randomSpheres.html"),
         resourceLocation = ResourceLocation.EMBED

playground/src/jvmMain/kotlin/simpleCube.kt

@@ -7,6 +7,7 @@ import hep.dataforge.vision.html.ResourceLocation
 import hep.dataforge.vision.html.fragment
 import hep.dataforge.vision.solid.box
 import hep.dataforge.vision.solid.solid
+import hep.dataforge.vision.solid.withSolids
 
 @OptIn(DFExperimental::class)
 fun main() {
@@ -18,5 +19,5 @@ fun main() {
         }
     }
 
-    VisionForge.makeVisionFile(content, resourceLocation = ResourceLocation.SYSTEM)
+    VisionForge.withSolids().makeVisionFile(content, resourceLocation = ResourceLocation.SYSTEM)
 }

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/VisionManager.kt

@@ -86,7 +86,6 @@ public abstract class VisionPlugin(meta: Meta = Meta.EMPTY) : AbstractPlugin(met
         VisionManager.VISION_SERIALIZER_MODULE_TARGET -> mapOf(tag.toString().toName() to visionSerializersModule)
         else -> super.content(target)
     }
-
 }
 
 /**

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/html/Page.kt

@@ -18,7 +18,7 @@ public data class Page(
                     fragment(it)
                 }
             }
-            title(title)
+            title(this@Page.title)
         }
         body {
             embedVisionFragment(context.visionManager, fragment = content)

visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/SolidManager.kt

@@ -68,4 +68,8 @@ public class SolidManager(meta: Meta) : VisionPlugin(meta) {
 
 @VisionBuilder
 @DFExperimental
-public inline fun VisionOutput.solid(block: SolidGroup.() -> Unit): SolidGroup = SolidGroup().apply(block)
+public inline fun VisionOutput.solid(block: SolidGroup.() -> Unit): SolidGroup = SolidGroup().apply(block)
+
+public fun Context.withSolids(): Context = apply {
+    plugins.fetch(SolidManager)
+}

visionforge-threejs/src/main/kotlin/hep/dataforge/vision/solid/three/ThreePlugin.kt

@@ -199,4 +199,8 @@ internal fun Object3D.findChild(name: Name): Object3D? {
         name.length == 1 -> this.children.find { it.name == name.tokens.first().toString() }
         else -> findChild(name.tokens.first().asName())?.findChild(name.cutFirst())
     }
+}
+
+public fun Context.withThreeJs(): Context = apply {
+    plugins.fetch(ThreePlugin)
 }