working on samples

samples/basic/viewer/main.cc

@@ -61,7 +61,84 @@ void basic_concepts(pm::vertex_attribute<tg::pos3> const& pos)
 
 void advanced_objects(pm::vertex_attribute<tg::pos3> const& pos)
 {
-    // lines, points, polygons
+    pm::Mesh const& m = pos.mesh();
+
+    // by default, gv::view(obj, ...) chooses gv::make_renderable(obj) to create a renderable
+    // this can be overridden by gv::polygons, gv::lines, gv::points
+
+    // by default, polymesh Meshes are rendered:
+    // - with gv::polygons if mesh.faces().size() > 0
+    // - otherwise with gv::lines if mesh.edges().size() > 0
+    // - otherwise with gv::points
+    // this can be overridden:
+    {
+        auto g = gv::grid();
+
+        gv::view(gv::polygons(pos), "gv::polygons(pos)");
+        gv::view(gv::lines(pos), "gv::lines(pos)");
+        gv::view(gv::points(pos), "gv::points(pos)");
+    }
+
+    // rendering can be customized by a builder-pattern:
+    {
+        // gv::polygons assumes planar faces and creates a triangle fan per face
+        // normals used for shading can be customized
+
+        auto g = gv::grid();
+
+        gv::view(gv::polygons(pos).face_normals(), "face normals (default)");
+        gv::view(gv::polygons(pos).smooth_normals(), "smooth normals");
+
+        pm::vertex_attribute<tg::vec3> vnormals = pm::vertex_normals_by_area(pos);
+        gv::view(gv::polygons(pos).normals(vnormals), "custom normals");
+
+        // see PolygonBuilder.hh for more information
+    }
+    {
+        // gv::lines performs line rendering
+        // by default, lines are rendered as 3D capsule with a fixed screen-space size
+        // customization includes
+        //   - billboard mode (camera-facing or oriented by normals)
+        //   - cap mode (round, square, none)
+        //   - line width (screen space or world space)
+
+        auto g = gv::grid();
+
+        pm::vertex_attribute<tg::vec3> vnormals = pm::vertex_normals_by_area(pos);
+        pm::vertex_attribute<float> line_widths = pos.map([](tg::pos3 p) { return 0.01f * tg::abs(p.x); });
+
+        gv::view(gv::lines(pos).camera_facing(), "camera facing");
+        gv::view(gv::lines(pos).line_width_world(0.01f).normals(vnormals), "oriented billboard lines");
+        gv::view(gv::lines(pos).line_width_world(0.01f).normals(vnormals).round_caps(), "round caps");
+        gv::view(gv::lines(pos).line_width_world(0.01f).normals(vnormals).square_caps(), "square caps");
+        gv::view(gv::lines(pos).line_width_world(0.01f).normals(vnormals).no_caps(), "no caps");
+        gv::view(gv::lines(pos).line_width_px(30), "30px line width");
+        gv::view(gv::lines(pos).line_width_world(0.01f), "1cm line width");
+        gv::view(gv::lines(pos).line_width_world(line_widths), "per-line width");
+
+        // see LineBuilder.hh for more information
+    }
+    {
+        auto g = gv::grid();
+
+        pm::vertex_attribute<tg::vec3> vnormals = pm::vertex_normals_by_area(pos);
+
+        // compute per-vertex average edge length as point size
+        pm::edge_attribute<float> edge_lengths = m.edges().map([&](pm::edge_handle e) { return edge_length(e, pos); });
+        pm::vertex_attribute<float> ptsize = m.vertices().map([&](pm::vertex_handle v) { return v.edges().avg(edge_lengths); });
+
+        // Square, oriented point cloud with adaptive point size
+        gv::view(gv::points(pos).point_size_world(ptsize).normals(vnormals).square(), "normal oriented squares");
+
+        gv::view(gv::points(pos).spheres().point_size_world(0.03f), "3D sphere cloud");
+
+        gv::view(gv::points(pos).camera_facing().unlit(), tg::color3::red, "no shading");
+
+        // see PointBuilder.hh for more information
+    }
+
+    // gv::polygons, gv::lines, gv::points can also be used to customize other inputs
+    // see typed_geometry_objects() example
 
     // TODO: text
     // TODO: images
@@ -75,7 +152,7 @@ void advanced_visualization(pm::vertex_attribute<tg::pos3> const& pos)
     // TODO: complex material (e.g. PBR)
 }
 
-void typed_geometry_objects(pm::vertex_attribute<tg::pos3> const& pos)
+void typed_geometry_objects()
 {
     auto g = gv::grid();
 
@@ -303,6 +380,8 @@ void headless_screenshot(pm::vertex_attribute<tg::pos3> const& pos)
 
 void special_use_cases(pm::vertex_attribute<tg::pos3> const& pos)
 {
+    // TODO: decoupled camera
+
     gv::view(pos, gv::maybe_empty, "allows empty renderable");
 
     gv::view(pos, gv::infinite_accumulation, "progressive rendering is not stopped early");
@@ -386,7 +465,7 @@ int main()
     {
         advanced_objects(pos);
 
-        typed_geometry_objects(pos);
+        typed_geometry_objects();
 
         advanced_visualization(pos);
 
@@ -410,9 +489,6 @@ int main()
 
     // Grid of examples
     {
-        // smooth normals
-        gv::view(gv::polygons(pos).smooth_normals(), "smoothed normals");
-
         // Configuration nesting
         {
             // Colored faces
@@ -436,18 +512,6 @@ int main()
         // Textured mesh (async texture)
         gv::view(pos, gv::textured(uv, atex), "textured (async)");
 
-        // Simple point cloud
-        gv::view(gv::points(pos), "point cloud");
-
-        // Square, oriented point cloud with adaptive point size
-        gv::view(gv::points(pos).point_size_world(ptsize).normals(vnormals).square(), "normal oriented squares");
-
-        // Points rendered as 3D spheres
-        gv::view(gv::points(pos).spheres().point_size_world(0.03f), "sphere cloud");
-
-        // Simple line soup
-        gv::view(gv::lines(pos), "edges");
-
         // transparencies
         gv::view(pos, tg::color4(0, 0.4f, 0.3f, 0.2f), "transparency with fresnel");
         gv::view(pos, tg::color4(0, 0.4f, 0.3f, 0.2f), gv::no_fresnel, "transparency without fresnel");