[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [36630] trunk/blender/release/scripts/ modules/view3d_utils.py: python utility module for converting between 2d/ 3d region/world coordinates.

[Campbell Barton]

Revision: 36630
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=36630
Author:   campbellbarton
Date:     2011-05-12 06:32:21 +0000 (Thu, 12 May 2011)
Log Message:
-----------
python utility module for converting between 2d/3d region/world coordinates.

Added Paths:
-----------
    trunk/blender/release/scripts/modules/view3d_utils.py

Added: trunk/blender/release/scripts/modules/view3d_utils.py
===================================================================
--- trunk/blender/release/scripts/modules/view3d_utils.py	                        (rev 0)
+++ trunk/blender/release/scripts/modules/view3d_utils.py	2011-05-12 06:32:21 UTC (rev 36630)
@@ -0,0 +1,94 @@
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ##### END GPL LICENSE BLOCK #####
+
+# <pep8 compliant>
+
+import bpy
+
+def region_2d_to_vector_3d(region, rv3d, coord):
+    """
+    Return a direction vector from the viewport at the spesific 2d region
+    coordinate.
+
+    :arg region: region of the 3D viewport, typically bpy.context.region.
+    :type region: :class:`Region`
+    :arg rv3d: 3D region data, typically bpy.context.space_data.region_3d.
+    :type rv3d: :class:`RegionView3D`
+    :arg coord: 2d coordinates relative to the region;
+       (event.mouse_region_x, event.mouse_region_y) for example.
+    :type coord: 2d vector
+    :return: normalized 3d vector.
+    :rtype: :class:`Vector`
+    """
+    from mathutils import Vector
+
+    dx = (2.0 * coord[0] / region.width) - 1.0
+    dy = (2.0 * coord[1] / region.height) - 1.0
+
+    viewvec = rv3d.view_matrix.inverted()[2].to_3d().normalized()
+    perspinv_x, perspinv_y = rv3d.perspective_matrix.inverted().to_3x3()[0:2]
+    return ((perspinv_x * dx + perspinv_y * dy) - viewvec).normalized()
+
+
+def region_2d_to_location_3d(region, rv3d, coord, depth_location):
+    """
+    Return a direction vector from the viewport at the spesific 2d region
+    coordinate.
+
+    :arg region: region of the 3D viewport, typically bpy.context.region.
+    :type region: :class:`Region`
+    :arg rv3d: 3D region data, typically bpy.context.space_data.region_3d.
+    :type rv3d: :class:`RegionView3D`
+    :arg coord: 2d coordinates relative to the region;
+       (event.mouse_region_x, event.mouse_region_y) for example.
+    :type coord: 2d vector
+    :arg depth_location: the returned vectors depth is aligned with this since
+       there is no defined depth with a 2d region input.
+    :type depth_location: 3d vector
+    :return: normalized 3d vector.
+    :rtype: :class:`Vector`
+    """
+    from mathutils.geometry import intersect_point_line
+    origin_start = rv3d.view_matrix.inverted()[3].to_3d()
+    origin_end = origin_start + region_2d_to_vector_3d(region, rv3d, coord)
+    return intersect_point_line(depth_vector, origin_start, origin_end)[0]
+
+
+def location_3d_to_region_2d(region, rv3d, coord):
+    """
+    Return the *region* relative 2d location of a 3d position.
+
+    :arg region: region of the 3D viewport, typically bpy.context.region.
+    :type region: :class:`Region`
+    :arg rv3d: 3D region data, typically bpy.context.space_data.region_3d.
+    :type rv3d: :class:`RegionView3D`
+    :arg coord: 3d worldspace location.
+    :type coord: 3d vector
+    :return: 2d location
+    :rtype: :class:`Vector`
+    """
+    prj = Vector((coord[0], coord[1], coord[2], 1.0)) * rv3d.perspective_matrix
+    if prj.w > 0.0:
+        width_half = region.width / 2.0
+        height_half = region.height / 2.0
+
+        return Vector((width_half + width_half * (prj.x / prj.w),
+                       height_half + height_half * (prj.y / prj.w),
+                       ))
+    else:
+        return None