#1153. Elevation references are now auto generated when activating drawings.

src/blenderbim/blenderbim/bim/module/drawing/decoration.py

@@ -1125,6 +1125,101 @@ class GridDecorator(BaseDecorator):
         self.draw_label(context, text, p1, dir, vcenter=True, gap=0)
 
 
+class ElevationDecorator(LevelDecorator):
+    objecttype = "ELEVATION"
+
+    DEF_GLSL = (
+        BaseDecorator.DEF_GLSL
+        + """
+        #define CIRCLE_SIZE 8.0
+        #define TRIANGLE_L 22.63
+        #define TRIANGLE_W 11.31
+    """
+    )
+
+    GEOM_GLSL = """
+    uniform vec2 winsize;
+    uniform float viewportDrawingScale;
+
+    layout(lines) in;
+    layout(line_strip, max_vertices=MAX_POINTS) out;
+
+    void triangle_head(in vec4 side, in vec4 dir, in float length, in float width, in float radius, out vec4 head[5]) {
+        vec4 nose = side * length;
+        vec4 ear = dir * width;
+        head[0] = side * -radius;
+        head[1] = nose * -.5;
+        head[2] = vec4(0) + ear;
+        head[3] = nose * .5;
+        head[4] = side * radius;
+    }
+
+    void main() {
+        vec4 clip2win = matCLIP2WIN();
+        vec4 win2clip = matWIN2CLIP();
+
+        vec4 p0 = gl_in[0].gl_Position, p1 = gl_in[1].gl_Position;
+
+        vec4 p0w = CLIP2WIN(p0), p1w = CLIP2WIN(p1);
+        vec4 edge = p1w - p0w, dir = normalize(edge);
+        // vec4 dir = normalize(vec4(1, 0, 0, 0));
+        vec4 gap = dir * viewportDrawingScale * TRIANGLE_L * .5;
+        vec4 side = vec4(cross(vec3(dir.xy, 0), vec3(0, 0, 1)).xy, 0, 0);
+        vec4 p;
+
+        vec4 head[CIRCLE_SEGS];
+        circle_head(viewportDrawingScale * CIRCLE_SIZE, head);
+
+        vec4 head3[5];
+
+        // start edge circle
+        for(int i=0; i<CIRCLE_SEGS; i++) {
+            p = p0w + head[i];
+            gl_Position = WIN2CLIP(p);
+            EmitVertex();
+        }
+        p = p0w + head[0];
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        EndPrimitive();
+
+        // start edge triangle
+        triangle_head(side, dir, viewportDrawingScale * TRIANGLE_L, viewportDrawingScale * TRIANGLE_W, viewportDrawingScale * CIRCLE_SIZE, head3);
+        p = p0w + head3[0];
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        p = p0w + head3[1];
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        p = p0w + head3[2];
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        p = p0w + head3[3];
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        p = p0w + head3[4];
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        EndPrimitive();
+
+        // reference divider
+        p = p0w + normalize(vec4(-1, 0, 0, 0)) * viewportDrawingScale * CIRCLE_SIZE;
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        p = p0w + normalize(vec4(1, 0, 0, 0)) * viewportDrawingScale * CIRCLE_SIZE;
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        EndPrimitive();
+    }
+    """
+
+    def decorate(self, context, obj):
+        center = obj.matrix_world.translation
+        v1 = obj.matrix_world @ Vector((0, 0, 0))
+        v2 = obj.matrix_world @ Vector((0, 0, -1))
+        self.draw_lines(context, obj, [v1, v2], [(0, 1)])
+
+
 class SectionViewDecorator(LevelDecorator):
     objecttype = "SECTION"
 
@@ -1328,6 +1423,7 @@ class DecorationsHandler:
         StairDecorator,
         BreakDecorator,
         SectionViewDecorator,
+        ElevationDecorator,
         TextDecorator,
     ]
 

src/blenderbim/blenderbim/core/drawing.py

@@ -173,7 +173,13 @@ def sync_references(ifc, collector, drawing_tool, drawing=None):
         should_delete_existing_annotation = False
         should_create_annotation = False
 
-        if annotation and (not reference_obj or ifc.is_moved(reference_obj) or ifc.is_edited(reference_obj)):
+        if annotation and (
+            not reference_obj
+            or ifc.is_moved(reference_obj)
+            or ifc.is_edited(reference_obj)
+            or ifc.is_deleted(reference_element)
+            or ifc.is_deleted(annotation)
+        ):
             should_delete_existing_annotation = True
 
         if reference_obj and (should_delete_existing_annotation or not annotation):

src/blenderbim/blenderbim/tool/drawing.py

@@ -19,6 +19,7 @@
 import os
 import re
 import bpy
+import math
 import bmesh
 import mathutils
 import webbrowser
@@ -407,6 +408,95 @@ class Drawing(blenderbim.core.tool.Drawing):
     def generate_reference_annotation(cls, drawing, reference_element, context):
         if reference_element.is_a("IfcGridAxis"):
             return cls.generate_grid_axis_reference_annotation(drawing, reference_element, context)
+        elif reference_element.is_a("IfcAnnotation") and reference_element.ObjectType == "DRAWING":
+            psets = ifcopenshell.util.element.get_psets(reference_element)
+            target_view = psets.get("EPset_Drawing", {}).get("TargetView", None)
+            if target_view == "ELEVATION_VIEW":
+                return cls.generate_elevation_reference_annotation(drawing, reference_element, context)
+
+    @classmethod
+    def generate_elevation_reference_annotation(cls, drawing, reference_element, context):
+        reference_obj = tool.Ifc.get_object(reference_element)
+        reference_obj.matrix_world
+        camera = tool.Ifc.get_object(drawing)
+
+        def is_perpendicular(a, b):
+            axes = [mathutils.Vector((1, 0, 0)), mathutils.Vector((0, 1, 0)), mathutils.Vector((0, 0, 1))]
+            a_quaternion = a.matrix_world.to_quaternion()
+            b_quaternion = b.matrix_world.to_quaternion()
+            for axis in axes:
+                if abs((a_quaternion @ axis).angle((b_quaternion @ axis)) - (math.pi / 2)) < 1e-5:
+                    return True
+            return False
+
+        def get_camera_block(obj):
+            raster_x = obj.data.BIMCameraProperties.raster_x
+            raster_y = obj.data.BIMCameraProperties.raster_y
+
+            if raster_x > raster_y:
+                width = obj.data.ortho_scale
+                height = width / raster_x * raster_y
+            else:
+                height = obj.data.ortho_scale
+                width = height / raster_y * raster_x
+            depth = obj.data.clip_end
+
+            verts = (
+                obj.matrix_world @ mathutils.Vector((-width / 2, -height /2, -depth)),
+                obj.matrix_world @ mathutils.Vector((-width / 2, -height /2, 0)),
+                obj.matrix_world @ mathutils.Vector((-width / 2, height /2, -depth)),
+                obj.matrix_world @ mathutils.Vector((-width / 2, height /2, 0)),
+                obj.matrix_world @ mathutils.Vector((width / 2, -height /2, -depth)),
+                obj.matrix_world @ mathutils.Vector((width / 2, -height /2, 0)),
+                obj.matrix_world @ mathutils.Vector((width / 2, height /2, -depth)),
+                obj.matrix_world @ mathutils.Vector((width / 2, height /2, 0))
+            )
+            faces = [
+                [0, 1, 3, 2],
+                [2, 3, 7, 6],
+                [6, 7, 5, 4],
+                [4, 5, 1, 0],
+                [2, 6, 4, 0],
+                [7, 3, 1, 5],
+            ]
+            return {"verts": verts, "faces": faces}
+
+        def is_intersecting(a, b):
+            a_block = get_camera_block(a)
+            a_tree = mathutils.bvhtree.BVHTree.FromPolygons(a_block["verts"], a_block["faces"])
+            b_block = get_camera_block(b)
+            b_tree = mathutils.bvhtree.BVHTree.FromPolygons(b_block["verts"], b_block["faces"])
+            return bool(a_tree.overlap(b_tree))
+
+        def to_camera_coords(camera, reference_obj):
+            mat = reference_obj.matrix_world.copy()
+            xyz = camera.matrix_world.inverted() @ reference_obj.matrix_world.translation
+            xyz[2] = 0
+            xyz = camera.matrix_world @ xyz
+            mat[0][3] = xyz[0]
+            mat[1][3] = xyz[1]
+            mat[2][3] = xyz[2]
+            annotation_offset = mathutils.Vector((0, 0, -camera.data.clip_start))
+            annotation_offset = camera.matrix_world.to_quaternion() @ annotation_offset
+            mat[0][3] += annotation_offset[0]
+            mat[1][3] += annotation_offset[1]
+            mat[2][3] += annotation_offset[2]
+            return mat
+
+        if is_perpendicular(camera, reference_obj) and is_intersecting(camera, reference_obj):
+            obj = bpy.data.objects.new(reference_obj.name, None)
+            obj.empty_display_size = 0.1
+            obj.matrix_world = to_camera_coords(camera, reference_obj)
+
+            element = cls.run_root_assign_class(
+                obj=obj,
+                ifc_class="IfcAnnotation",
+                predefined_type="ELEVATION",
+                should_add_representation=False,
+                context=context,
+                ifc_representation_class=None,
+            )
+            return element
 
     @classmethod
     def generate_grid_axis_reference_annotation(cls, drawing, reference_element, context):