PointCloud: Initial rendering support for Workbench

Also includes outline overlays. Removes the temp overlay drawing

We make the geometry follow camera like billboards this uses less
geometry. Currently we use half octahedron for now. Goal would be
to use icospheres.

This patch also optimize the case when pointcloud has uniform radius.
However we should premultiply the radius prop by the default radius
beforehand to avoid a multiplication on CPU.

Using geometry instead of pseudo raytraced spheres is more scalable as
we can render as low as 1 or 2 triangle to a full half sphere and can
integrate easily in the render pipeline using a low amount of code.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D8301

2 files changed, 40 insertions, 0 deletions

diff --git a/source/blender/draw/intern/shaders/common_pointcloud_lib.glsl b/source/blender/draw/intern/shaders/common_pointcloud_lib.glsl
new file mode 100644
index 00000000000..36b67f2bd60
--- /dev/null
+++ b/source/blender/draw/intern/shaders/common_pointcloud_lib.glsl
@@ -0,0 +1,39 @@
+
+/* NOTE: To be used with UNIFORM_RESOURCE_ID and INSTANCED_ATTR as define. */
+#pragma BLENDER_REQUIRE(common_view_lib.glsl)
+
+in vec4 pos; /* Position and radius. */
+
+/* ---- Instanced attribs ---- */
+
+in vec3 pos_inst;
+in vec3 nor;
+
+mat3 pointcloud_get_facing_matrix(vec3 p)
+{
+  mat3 facing_mat;
+  facing_mat[2] = normalize(ViewMatrixInverse[3].xyz - p);
+  facing_mat[1] = normalize(cross(ViewMatrixInverse[0].xyz, facing_mat[2]));
+  facing_mat[0] = cross(facing_mat[1], facing_mat[2]);
+  return facing_mat;
+}
+
+/* Return world position and normal. */
+void pointcloud_get_pos_and_nor(out vec3 outpos, out vec3 outnor)
+{
+  vec3 p = point_object_to_world(pos.xyz);
+  mat3 facing_mat = pointcloud_get_facing_matrix(p);
+
+  float radius = dot(abs(mat3(ModelMatrix) * pos.www), vec3(1.0 / 3.0));
+  /* TODO(fclem) remove multiplication here. Here only for keeping the size correct for now. */
+  radius *= 0.01;
+  outpos = p + (facing_mat * pos_inst) * radius;
+  outnor = facing_mat * nor;
+}
+
+vec3 pointcloud_get_pos(void)
+{
+  vec3 outpos, outnor;
+  pointcloud_get_pos_and_nor(outpos, outnor);
+  return outpos;
+}
\ No newline at end of file
diff --git a/source/blender/draw/intern/shaders/common_view_lib.glsl b/source/blender/draw/intern/shaders/common_view_lib.glsl
index 2188c38ee63..095bc64a19e 100644
--- a/source/blender/draw/intern/shaders/common_view_lib.glsl
+++ b/source/blender/draw/intern/shaders/common_view_lib.glsl
@@ -175,6 +175,7 @@ uniform mat4 ModelMatrixInverse;
 #define normal_object_to_world(n) (transpose(mat3(ModelMatrixInverse)) * n)
 #define normal_world_to_object(n) (transpose(mat3(ModelMatrix)) * n)
 #define normal_world_to_view(n) (mat3(ViewMatrix) * n)
+#define normal_view_to_world(n) (mat3(ViewMatrixInverse) * n)
 
 #define point_object_to_ndc(p) (ViewProjectionMatrix * vec4((ModelMatrix * vec4(p, 1.0)).xyz, 1.0))
 #define point_object_to_view(p) ((ViewMatrix * vec4((ModelMatrix * vec4(p, 1.0)).xyz, 1.0)).xyz)