diff --git a/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionGroupBase.kt b/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionGroupBase.kt
index 44800673..997789c1 100644
--- a/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionGroupBase.kt
+++ b/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionGroupBase.kt
@@ -17,7 +17,7 @@ import space.kscience.dataforge.names.*
 @Serializable
 @SerialName("vision.group")
 public open class VisionGroupBase(
-    @SerialName("children") internal val childrenInternal: MutableMap<NameToken, Vision> = LinkedHashMap(),
+    @SerialName("children") protected val childrenInternal: MutableMap<NameToken, Vision> = LinkedHashMap(),
 ) : VisionBase(), MutableVisionGroup {
 
     /**
diff --git a/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidGroup.kt b/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidGroup.kt
index ad2107f0..513a6fc9 100644
--- a/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidGroup.kt
+++ b/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidGroup.kt
@@ -29,9 +29,6 @@ public interface PrototypeHolder {
 @SerialName("group.solid")
 public class SolidGroup(
     @Serializable(PrototypeSerializer::class) internal var prototypes: MutableVisionGroup? = null,
-//    override var position: Point3D? = null,
-//    override var rotation: Point3D? = null,
-//    override var scale: Point3D? = null,
 ) : VisionGroupBase(), Solid, PrototypeHolder {
 
     init {
diff --git a/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidReference.kt b/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidReference.kt
index 3d067a62..8778657f 100644
--- a/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidReference.kt
+++ b/visionforge-solid/src/commonMain/kotlin/space/kscience/visionforge/solid/SolidReference.kt
@@ -95,23 +95,6 @@ public class SolidReferenceGroup(
      * (properties are stored in external cache) and created and destroyed on-demand).
      */
     private inner class ReferenceChild(private val childName: Name) : SolidReference, VisionGroup {
-
-//        //TODO replace by properties
-//        override var position: Point3D?
-//            get() = prototype.position
-//            set(_) {
-//                error("Can't set position of reference")
-//            }
-//        override var rotation: Point3D?
-//            get() = prototype.rotation
-//            set(_) {
-//                error("Can't set position of reference")
-//            }
-//        override var scale: Point3D?
-//            get() = prototype.scale
-//            set(_) {
-//                error("Can't set position of reference")
-//            }
         override val prototype: Solid get() = prototypeFor(childName)
 
         override val children: Map<NameToken, Vision>