diff --git a/data/layout.xml b/data/layout.xml
index 6b1db2b..35d5245 100644
--- a/data/layout.xml
+++ b/data/layout.xml
@@ -316,7 +316,7 @@
             <!--<node height="20" pad="1" width="100%"><slider-h id="grid-heightmap-thickness" value="0.5"/></node>-->
             <node height="20" pad="1" width="100%"><slider-h id="grid-heightmap-height" value="0.25"/></node>
             <node height="20" pad="1" width="100%"><slider-h id="grid-heightmap-lyaw" value="0.5"/></node>
-            <node height="20" pad="1" width="100%"><slider-h id="grid-heightmap-lpitch" value="0.5"/></node>
+            <node height="20" pad="1" width="100%"><slider-h id="grid-heightmap-lpitch" value="0.1"/></node>
             <node height="20" pad="1" width="100%"><slider-h id="grid-heightmap-ambient" value="0.0"/></node>
             <node height="30" pad="1" width="100%" dir="row" margin="5 0 0 0">
               <combobox id="grid-heightmap-samples" width="100%" height="30" combo-list="1,4,8,16,32,64,128" default="2"/>
diff --git a/src/canvas.cpp b/src/canvas.cpp
index 2315e20..a7712b0 100644
--- a/src/canvas.cpp
+++ b/src/canvas.cpp
@@ -2221,6 +2221,12 @@ void Canvas::draw_objects(std::function<void(const glm::mat4& camera, const glm:
     glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, layer.w, layer.h);
     glBindRenderbuffer(GL_RENDERBUFFER, 0);
 
+    RTT rtt;
+    rtt.create(layer.w, layer.h);
+    rtt.bindFramebuffer();
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rboID);
+    rtt.unbindFramebuffer();
+
     // allocate action to add to history
     auto action = new ActionStroke;
     action->was_saved = !m_unsaved;
@@ -2229,14 +2235,12 @@ void Canvas::draw_objects(std::function<void(const glm::mat4& camera, const glm:
     for (int i = 0; i < 6; i++)
     {
         glm::mat4 plane_camera = glm::lookAt(glm::vec3(0), m_plane_origin[i], m_plane_tangent[i]);
-        m_tmp[i].bindFramebuffer();
-        m_tmp[i].clear({ 1, 1, 1, 0 });
-        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rboID);
+        rtt.bindFramebuffer();
+        rtt.clear({ 1, 1, 1, 0 });
         observer(plane_camera, proj, i);
-        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, 0);
-        m_tmp[i].unbindFramebuffer();
+        rtt.unbindFramebuffer();
 
-        glm::vec4 bounds = m_tmp[i].calc_bounds();
+        glm::vec4 bounds = rtt.calc_bounds();
 
         layer.m_rtt[i].bindFramebuffer();
 
@@ -2246,9 +2250,9 @@ void Canvas::draw_objects(std::function<void(const glm::mat4& camera, const glm:
         {
             action->m_image[i] = std::make_unique<uint8_t[]>(box_sz.x * box_sz.y * 4);
             glReadPixels(bounds.x, bounds.y, box_sz.x, box_sz.y, GL_RGBA, GL_UNSIGNED_BYTE, action->m_image[i].get());
+            action->m_box[i] = bounds;
         }
 
-        action->m_box[i] = bounds;
         action->m_old_box[i] = layer.m_dirty_box[i];
         action->m_old_dirty[i] = layer.m_dirty_face[i];
 
@@ -2258,9 +2262,9 @@ void Canvas::draw_objects(std::function<void(const glm::mat4& camera, const glm:
         ShaderManager::u_mat4(kShaderUniform::MVP, glm::ortho(-0.5f, 0.5f, -0.5f, 0.5f));
         glActiveTexture(GL_TEXTURE0);
         m_sampler_nearest.bind(0);
-        m_tmp[i].bindTexture();
+        rtt.bindTexture();
         m_plane.draw_fill();
-        m_tmp[i].unbindTexture();
+        rtt.unbindTexture();
 
         layer.m_rtt[i].unbindFramebuffer();
 
@@ -2275,6 +2279,7 @@ void Canvas::draw_objects(std::function<void(const glm::mat4& camera, const glm:
     ActionManager::add(action);
 
     glDeleteRenderbuffers(1, &rboID);
+    rtt.destroy();
 
     // restore viewport and clear color states
     blend ? glEnable(GL_BLEND) : glDisable(GL_BLEND);
diff --git a/src/node_canvas.cpp b/src/node_canvas.cpp
index c5d7454..e962abc 100644
--- a/src/node_canvas.cpp
+++ b/src/node_canvas.cpp
@@ -351,7 +351,7 @@ void NodeCanvas::draw()
         for (auto& mode : Canvas::modes[(int)Canvas::kCanvasMode::Grid])
             mode->on_Draw(ortho_proj, proj, camera);
 
-    App::I.grid->draw_heightmap(proj, camera);
+    App::I.grid->draw_heightmap(proj, camera, false);
 
     for (auto& mode : *m_canvas->m_mode)
         mode->on_Draw(ortho_proj, proj, camera);
diff --git a/src/node_panel_grid.cpp b/src/node_panel_grid.cpp
index d8bf69d..2da1bff 100644
--- a/src/node_panel_grid.cpp
+++ b/src/node_panel_grid.cpp
@@ -134,7 +134,7 @@ void NodePanelGrid::init_controls()
         gl_state gl;
         gl.save();
         Canvas::I->draw_objects([this](const glm::mat4& camera, const glm::mat4& proj, int i) {
-            draw_heightmap(proj, camera);
+            draw_heightmap(proj, camera, true);
         });
         m_groud_opacity->set_value(0);
         gl.restore();
@@ -156,9 +156,12 @@ void NodePanelGrid::init_controls()
     };
     int rexres = get_texres();
     m_texture.create(rexres, rexres);
+    m_sampler_mipmap.create();
+    m_sampler_mipmap.set_filter(GL_LINEAR_MIPMAP_LINEAR, GL_LINEAR);
     m_sampler_linear.create();
-    m_sampler_linear.set_filter(GL_LINEAR_MIPMAP_LINEAR, GL_LINEAR);
-    m_sphere.create<8, 8>(.0001f);
+    m_plane.create<1>(1, 1);
+
+    TextureManager::load("data/sun.png");
 
     glGetFloatv(GL_SMOOTH_LINE_WIDTH_RANGE, m_line_range);
     //glGetFloatv(GL_ALIASED_LINE_WIDTH_GRANULARITY, &m_line_granularity);
@@ -199,7 +202,7 @@ float NodePanelGrid::get_offset() const
     return glm::pow(m_groud_offset->get_value() - 0.5f, 3);
 }
 
-void NodePanelGrid::draw_heightmap(const glm::mat4& proj, const glm::mat4& camera) const
+void NodePanelGrid::draw_heightmap(const glm::mat4& proj, const glm::mat4& camera, bool commit) const
 {
     if (m_groud_opacity->get_value() > 0.f)
     {
@@ -216,14 +219,7 @@ void NodePanelGrid::draw_heightmap(const glm::mat4& proj, const glm::mat4& camer
         auto light_pos = glm::vec3(sinf(light_yaw) + nav.x, light_pitch + get_offset(), cosf(light_yaw) + nav.y);
         auto light_dir = glm::normalize(light_pos);
 
-        // DRAW SUN SPHERE
         glDisable(GL_BLEND);
-        ShaderManager::use(kShader::Color);
-        ShaderManager::u_mat4(kShaderUniform::MVP, proj * camera * 
-            glm::translate(light_pos) * glm::scale(glm::vec3(.1f)));
-        ShaderManager::u_vec4(kShaderUniform::Col, { 1, 0, 0, 1 });
-        m_sphere.draw_fill();
-
         // DRAW SOLID
         if (m_hm_image.m_data)
         {
@@ -254,7 +250,7 @@ void NodePanelGrid::draw_heightmap(const glm::mat4& proj, const glm::mat4& camer
                 ShaderManager::u_vec3(kShaderUniform::LightDir, light_dir);
                 ShaderManager::u_float(kShaderUniform::Ambient, get_ambient());
                 ShaderManager::u_int(kShaderUniform::Tex, 0);
-                m_sampler_linear.bind(0);
+                m_sampler_mipmap.bind(0);
                 glActiveTexture(GL_TEXTURE0);
                 m_texture.bind();
                 m_hm_plane.draw_fill();
@@ -282,6 +278,29 @@ void NodePanelGrid::draw_heightmap(const glm::mat4& proj, const glm::mat4& camer
             }
             m_hm_plane.draw_stroke();
         }
+
+        // DRAW SUN SPHERE
+        if (!commit)
+        {
+            auto c = proj * camera * glm::translate(light_pos) * glm::vec4(0, 0, 0, 1);
+            if (c.w > 0)
+            {
+                auto p2d = xy(c) / c.z;
+                GLint vp[4];
+                glGetIntegerv(GL_VIEWPORT, vp);
+                auto aspect_ratio = (float)vp[3] / (float)vp[2];
+                glEnable(GL_BLEND);
+                ShaderManager::use(kShader::Texture);
+                ShaderManager::u_int(kShaderUniform::Tex, 0);
+                ShaderManager::u_mat4(kShaderUniform::MVP, glm::ortho(-1.f, 1.f, -1.f, 1.f) *
+                    glm::translate(glm::vec3(p2d, 0)) * glm::scale(glm::vec3(.1f * aspect_ratio, .1f, 1.f)));
+                glActiveTexture(GL_TEXTURE0);
+                m_sampler_linear.bind(0);
+                constexpr auto sun_tex = const_hash("data/sun.png");
+                TextureManager::get(sun_tex).bind();
+                m_plane.draw_fill();
+            }
+        }
     }
 }
 
diff --git a/src/node_panel_grid.h b/src/node_panel_grid.h
index 5e7ea83..73f5b3b 100644
--- a/src/node_panel_grid.h
+++ b/src/node_panel_grid.h
@@ -57,9 +57,10 @@ public:
     NodeButton* m_commit;
     HeightmapPlane m_hm_plane;
     NodeHeightmapOverlay* m_hm_preview_nav;
-    Sphere m_sphere;
+    Plane m_plane;
     Image m_hm_image;
     Texture2D m_texture;
+    Sampler m_sampler_mipmap;
     Sampler m_sampler_linear;
     std::string m_file_path;
     nanort::BVHAccel<float> m_rt_accel;
@@ -79,6 +80,6 @@ public:
     float get_resolution() const;
     float get_height() const;
     float get_offset() const;
-    void draw_heightmap(const glm::mat4& proj, const glm::mat4& camera) const;
+    void draw_heightmap(const glm::mat4& proj, const glm::mat4& camera, bool commit) const;
     void bake_uvs();
 };