Cycles: add Point Info node

With (center) position, radius and random value outputs.

Eevee does not yet support rendering point clouds, but an untested
implementation of this node was added for when it does.

Ref T92573

source/blender/draw/engines/eevee/eevee_private.h

@@ -176,7 +176,7 @@ enum {
   VAR_MAT_MESH = (1 << 0),
   VAR_MAT_VOLUME = (1 << 1),
   VAR_MAT_HAIR = (1 << 2),
-  /* VAR_MAT_PROBE = (1 << 3), UNUSED */
+  VAR_MAT_POINTCLOUD = (1 << 3),
   VAR_MAT_BLEND = (1 << 4),
   VAR_MAT_LOOKDEV = (1 << 5),
   VAR_MAT_HOLDOUT = (1 << 6),

source/blender/draw/engines/eevee/eevee_shaders.c

@@ -1357,6 +1357,9 @@ static char *eevee_get_defines(int options)
   if ((options & VAR_MAT_HAIR) != 0) {
     BLI_dynstr_append(ds, "#define HAIR_SHADER\n");
   }
+  if ((options & VAR_MAT_POINTCLOUD) != 0) {
+    BLI_dynstr_append(ds, "#define POINTCLOUD_SHADER\n");
+  }
   if ((options & VAR_WORLD_PROBE) != 0) {
     BLI_dynstr_append(ds, "#define PROBE_CAPTURE\n");
   }

source/blender/draw/engines/eevee/shaders/shadow_vert.glsl

@@ -26,6 +26,9 @@ void main()
 
   worldNormal = cross(hairTangent, binor);
   vec3 world_pos = pos;
+#elif defined(POINTCLOUD_SHADER)
+  pointcloud_get_pos_and_radius(pointPosition, pointRadius);
+  pointID = gl_VertexID;
 #else
   vec3 world_pos = point_object_to_world(pos);
 #endif

source/blender/draw/engines/eevee/shaders/surface_lib.glsl

@@ -42,3 +42,13 @@ IN_OUT ShaderHairInterface
   flat int hairStrandID;
 };
 #endif
+
+#ifdef POINTCLOUD_SHADER
+IN_OUT ShaderPointCloudInterface
+{
+  /* world space */
+  float pointRadius;
+  float pointPosition;
+  flat int pointID;
+};
+#endif

source/blender/draw/engines/eevee/shaders/surface_vert.glsl

@@ -31,6 +31,9 @@ void main()
                               hairThickTime);
   worldNormal = cross(hairTangent, binor);
   vec3 world_pos = pos;
+#elif defined(POINTCLOUD_SHADER)
+  pointcloud_get_pos_and_radius(pointPosition, pointRadius);
+  pointID = gl_VertexID;
 #else
   vec3 world_pos = point_object_to_world(pos);
 #endif