diff --git a/builtins/rendercore/RenderCore-1.7.tar.gz b/builtins/rendercore/RenderCore-1.7.tar.gz
deleted file mode 100644
index bbd5b97e2c661..0000000000000
Binary files a/builtins/rendercore/RenderCore-1.7.tar.gz and /dev/null differ
diff --git a/builtins/rendercore/RenderCore-1.8.tar.gz b/builtins/rendercore/RenderCore-1.8.tar.gz
new file mode 100644
index 0000000000000..084656c909f4e
Binary files /dev/null and b/builtins/rendercore/RenderCore-1.8.tar.gz differ
diff --git a/cmake/modules/SearchInstalledSoftware.cmake b/cmake/modules/SearchInstalledSoftware.cmake
index a6dedfbfaf3f8..7f78a1da35ddb 100644
--- a/cmake/modules/SearchInstalledSoftware.cmake
+++ b/cmake/modules/SearchInstalledSoftware.cmake
@@ -2157,8 +2157,8 @@ if(webgui)
   endif()
   ExternalProject_Add(
     RENDERCORE
-    URL ${CMAKE_SOURCE_DIR}/builtins/rendercore/RenderCore-1.7.tar.gz
-    URL_HASH SHA256=46cf6171ae0e16ba2f99789daaeb202146072af874ea530f06a0099c66c3e9b1
+    URL ${CMAKE_SOURCE_DIR}/builtins/rendercore/RenderCore-1.8.tar.gz
+    URL_HASH SHA256=2ab84800ec1aaf36671e463a09e3befbe97b06b2547f97ec05fe16ef1351c79a
     CONFIGURE_COMMAND ""
     BUILD_COMMAND ""
     INSTALL_COMMAND ""
diff --git a/graf3d/eve7/src/REveBoxSet.cxx b/graf3d/eve7/src/REveBoxSet.cxx
index abcffce6d223d..c1bbcdede60a7 100644
--- a/graf3d/eve7/src/REveBoxSet.cxx
+++ b/graf3d/eve7/src/REveBoxSet.cxx
@@ -238,7 +238,7 @@ void REveBoxSet::AddHex(const REveVector& pos, Float_t r, Float_t angle, Float_t
    REveTrans t; // AMT do we need to reuse ???
    t.SetPos(pos.fX, pos.fY, pos.fZ);
    t.SetScale(r,r,depth);
-   t.RotatePF(1, 2, angle);
+   t.RotateLF(1, 2, angle * TMath::DegToRad());
    for(Int_t i=0; i<16; ++i)
    hex->fMat[i] = t[i];
 }
diff --git a/ui5/eve7/lib/EveScene.js b/ui5/eve7/lib/EveScene.js
index fa5e42d660595..e0ef39d79965f 100644
--- a/ui5/eve7/lib/EveScene.js
+++ b/ui5/eve7/lib/EveScene.js
@@ -201,8 +201,15 @@ sap.ui.define(['rootui5/eve7/lib/EveManager'], function(EveManager) {
                this.update3DObjectsVisibility(p.childs, true);
                this.need_visibility_update = false;
             }
-            this.glctrl.viewer.render();
 
+            // To improve when bbox info is streamed.
+            // Recalc scene bbox -- and update viewer total bbox, from scene boxes.
+            // 1. recalc-scene-bbox from known element bboxes (streamed)
+            //    [ this could really be done on the server ]
+            // 2. tell viewer to recalc-total-bbox ONLY from scene bboxes.
+
+            // For now just refresh the gl-viewer.
+            this.glctrl.viewer.request_render(true);
          }
       }
 
diff --git a/ui5/eve7/lib/GlViewerRCore.js b/ui5/eve7/lib/GlViewerRCore.js
index 2fea3fa43a8d1..e9abf2ac505e3 100644
--- a/ui5/eve7/lib/GlViewerRCore.js
+++ b/ui5/eve7/lib/GlViewerRCore.js
@@ -87,6 +87,8 @@ sap.ui.define([
                   return canvasDOM;
                };
 
+               pthis.ApplyTemporaryRCoreExtensions();
+
                pthis.bootstrap();
             });
          } else {
@@ -203,6 +205,7 @@ sap.ui.define([
          this.renderer.clearColor = "#00000000";
          this.scene = new RC.Scene();
          this.overlay_scene = new RC.Scene();
+         this.scene_bbox = new RC.Box3();
 
          this.lights = new RC.Group;
          this.lights.name = "Light container";
@@ -470,18 +473,23 @@ sap.ui.define([
          this.resetRenderer();
       }
 
-      resetRenderer()
+      recalcSceneBBox()
       {
-         let sbbox = new RC.Box3();
-         sbbox.setFromObject( this.scene );
-         if (sbbox.isEmpty())
+         this.scene_bbox.setFromObject( this.scene );
+         if (this.scene_bbox.isEmpty())
          {
-            console.error("GlViewerRenderCore.resetRenderer scene bbox empty", sbbox);
+            console.error("GlViewerRenderCore.resetRenderer scene bbox empty", this.scene_bbox);
             const ext = 100;
-            sbbox.expandByPoint(new RC.Vector3(-ext,-ext,-ext));
-            sbbox.expandByPoint(new RC.Vector3( ext, ext, ext));
+            this.scene_bbox.expandByPoint(new RC.Vector3(-ext,-ext,-ext));
+            this.scene_bbox.expandByPoint(new RC.Vector3( ext, ext, ext));
          }
+      }
+
+      resetRenderer()
+      {
+         this.recalcSceneBBox();
 
+         let sbbox = this.scene_bbox;
          let posV = new RC.Vector3; posV.subVectors(sbbox.max, this.rot_center);
          let negV = new RC.Vector3; negV.subVectors(sbbox.min, this.rot_center);
 
@@ -540,6 +548,19 @@ sap.ui.define([
          this.controls.update();
       }
 
+      setupCamera()
+      {
+         // To be used with JS debugger to edit the values as needed.
+
+         let pos = new RC.Vector3;
+         let lookat = new RC.Vector3;
+         let fov = 30; // in degrees
+
+         console.log("A good place to set the breakpoint and edit the values");
+
+         // Call the controller stuff, hope it's not all local, otherwise we need to edit it there.
+         // Sigh, should really have it (and RedeQuTor) in ROOT.
+      }
 
       updateViewerAttributes()
       {
@@ -641,10 +662,11 @@ sap.ui.define([
 
       //==============================================================================
 
-      request_render()
+      request_render(recalc_sbbox=false)
       {
          // console.log("REQUEST RENDER");
 
+         this.render_requested_recalc_sbbox ||= recalc_sbbox;
          if (this.render_requested) return;
          setTimeout(this.render.bind(this), 0);
          this.render_requested = true;
@@ -652,9 +674,16 @@ sap.ui.define([
 
       render()
       {
-         // console.log("RENDER", this.scene, this.camera, this.canvas, this.renderer);
+         console.log("RENDER", this.scene, this.camera, this.canvas, this.renderer);
 
          this.render_requested = false;
+         if (this.render_requested_recalc_sbbox) {
+            this.recalcSceneBBox();
+            this.render_requested_recalc_sbbox = false;
+         }
+         if (this.camera.isPerspectiveCamera) {
+            this.camera.optimizeNearFar(this.scene_bbox);
+         }
 
          if (this.canvas.width <= 0 || this.canvas.height <= 0) return;
 
@@ -1220,6 +1249,25 @@ sap.ui.define([
          </html>`);
          win.document.close();
       }
+
+      //==============================================================================
+      // Temporary RCore additions (to avoid updating of RCore.tgz)
+      //==============================================================================
+
+      ApplyTemporaryRCoreExtensions() {
+         console.log("GlViewerRCore.ApplyTemporaryRCoreExtensions()");
+
+         // E.g.:
+         // if (RC.PerspectiveCamera.prototype.optimizeNearFar === undefined) {
+         //    RC.PerspectiveCamera.prototype.optimizeNearFar = function(scene_bbox) {
+         //       this.matrixWorldInverse.getInverse(this.matrixWorld);
+         //       // .....
+         //    };
+         // }
+      }
+
+      //==============================================================================
+
    } // class GlViewerRCore
 
    return GlViewerRCore;