Update multiple viewers

Author: GitHubDragonFly

viewers/templates/GLTF WebGPU.html

@@ -1756,6 +1756,8 @@
           if (document.getElementById('file_image_input').value !== '') {
             set_bgenv_message();
             set_scene_image();
+          } else {
+            set_back_color();
           }
 
           scene.backgroundIntensity = 1.0;
@@ -1927,7 +1929,7 @@
         await reset_scene_params();
 
         if (bgnd_linear_gradient === true) {
-          bgnd_linear_gradient = false;
+          set_back_color();
           document.getElementById('btn_bgnd_linear_gradient').style.backgroundColor = 'transparent';
         } else {
           bgnd_linear_gradient = true;

viewers/templates/OBJ WebGPU.html

@@ -2576,6 +2576,8 @@
           if (document.getElementById('file_image_input').value !== '') {
             set_bgenv_message();
             set_scene_image();
+          } else {
+            set_back_color();
           }
 
           scene.backgroundBlurriness = 0.00001;
@@ -2745,7 +2747,7 @@
         await reset_scene_params();
 
         if (bgnd_linear_gradient === true) {
-          bgnd_linear_gradient = false;
+          set_back_color();
           document.getElementById('btn_bgnd_linear_gradient').style.backgroundColor = 'transparent';
         } else {
           bgnd_linear_gradient = true;