More NVIDIA-IndeX-plug-in 2.3 fixes

- Fixed random disspearing of irregular volumes in PV-Server.
- Fixed broken tile rendering.
- Gradient kernel cleanup.

Plugins/pvNVIDIAIndeX/src/kernel_gradient.cu

@@ -12,7 +12,7 @@ NV_IDX_XAC_VERSION_1_0
 
 struct Gradient_params
 {
-    float gradient; // [0.1, 1] gradient value
+    float gradient; // [0.01, 1] gradient value
     float grad_max; // 20.0f maximum gradient scale
     float dummy1;
     float dummy2;
@@ -74,9 +74,6 @@ public:
         // check if sample can be skipped
         if (sample_color.w < min_alpha) return NV_IDX_PROG_DISCARD_SAMPLE;
 
-        // compute volume gradient (local version)
-        //const float3 vol_grad = get_gradient(sampler, sample_position, dh);
-
         // compute volume gradient (use trilinear filter for gradients)
         const float3 vol_grad = volume_gradient<Volume_filter_mode::TRILINEAR>(
                     sparse_volume,

Plugins/pvNVIDIAIndeX/src/nvindex.xml

@@ -767,7 +767,7 @@
           </IntVectorProperty>
 
           <DoubleVectorProperty
-              label="Level"
+              label="Gradient Level"
               name="gradient_level"
               command="set_gradient_level"
               number_of_elements="1"
@@ -787,7 +787,7 @@
           </DoubleVectorProperty>
 
           <DoubleVectorProperty
-              label="Scale"
+              label="Gradient Scale"
               name="gradient_scale"
               command="set_gradient_scale"
               number_of_elements="1"

Plugins/pvNVIDIAIndeX/src/vtknvindex_irregular_volume_mapper.cxx

@@ -90,6 +90,8 @@ vtknvindex_irregular_volume_mapper::vtknvindex_irregular_volume_mapper()
   m_kd_tree = NULL;
   m_prev_property = "";
   m_last_MTime = 0;
+
+  vtkMath::UninitializeBounds(m_whole_bounds);
 }
 
 //----------------------------------------------------------------------------

Plugins/pvNVIDIAIndeX/src/vtknvindex_opengl_canvas.cxx

@@ -130,10 +130,10 @@ void vtknvindex_opengl_canvas::receive_tile(
 {
   m_vtk_renderer->GetRenderWindow()->MakeCurrent();
 
-  const mi::Uint32 src_width = area.max.x - area.min.x;
-  const mi::Uint32 src_height = area.max.y - area.min.y;
+  const mi::Sint32 src_width = area.max.x - area.min.x;
+  const mi::Sint32 src_height = area.max.y - area.min.y;
 
-  if (src_width == 0 || src_height == 0)
+  if (src_width <= 0 || src_height <= 0)
   {
     return;
   }
@@ -158,6 +158,9 @@ void vtknvindex_opengl_canvas::receive_tile(
     area.max.x > tile.max.x ? tile.max.x : area.max.x,
     area.max.y > tile.max.y ? tile.max.y : area.max.y };
 
+  if (src_tile.min.x >= src_tile.max.x || src_tile.min.y >= src_tile.max.y)
+    return;
+
   const mi::math::Bbox_struct<mi::Uint32, 2> dst_tile = { src_tile.min.x - tile.min.x,
     src_tile.min.y - tile.min.y, src_tile.max.x - tile.min.x, src_tile.max.y - tile.min.y };