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![Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 16 Creating Meshes for example: Tetrahedron import bpy s = 0.5**0.5 # 0.5*sqrt(2) verts = ((s,s,-1), (s,-s,-1), (-s,-s,-1), (-s,s,-1), (0,0,1)) faces = ((1,0,4), (4,2,1), (4,3,2), (4,0,3), (0,1,2,3)) mesh = bpy.data.meshes.new("TetrahedronMesh") object = bpy.data.objects.new("TetrahedronObject", mesh) object.location = (0,0,0) # origin scene = bpy.context.scene scene.objects.link(object) scene.objects.active = object object.select = True mesh.from_pydata(verts, [], faces) # vertices, edges, faces mesh.update()](https://image.slidesharecdn.com/presentationsmall-160205125512/75/3D-Computer-Graphics-with-Python-16-2048.jpg)
![Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 17 Real Life Example Using Python to optimize 3D objects: bpy.ops.object.select_all(action='DESELECT') bpy.context.scene.objects.active = bpy.data.objects[1] bpy.ops.object.select_all(action='SELECT') bpy.ops.object.join() bpy.ops.object.mode_set(mode='EDIT') bpy.ops.mesh.dissolve_limited() bpy.ops.mesh.remove_doubles(threshold=0.01) bpy.ops.mesh.select_all(action='DESELECT') bpy.ops.mesh.select_interior_faces() bpy.ops.mesh.delete(type='FACE') bpy.ops.object.mode_set(mode='OBJECT')](https://image.slidesharecdn.com/presentationsmall-160205125512/75/3D-Computer-Graphics-with-Python-17-2048.jpg)
![Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 24 How OpenGL Works Primitives (=Points, Linies, Triangles) are converted to Fragments (Pixels). Program Vertex-Operations (e.g. projection, transformation). Program Fragment-Operations for shading/lighting/texturing. Vertex/Fragment Shaders [run on the GPU and] are written in GLSL.](https://image.slidesharecdn.com/presentationsmall-160205125512/75/3D-Computer-Graphics-with-Python-24-2048.jpg)
![2.5.2016Institute of Geomatics Engineering 44 Viewer API map3d.js Library var map = new map3d.map("mapcanvas"); var layer = new map3d.imageLayer([ "http://t1.3dmaps.ch/tiles/teatime", "http://t2.3dmaps.ch/tiles/teatime", "http://t3.3dmaps.ch/tiles/teatime", "http://t4.3dmaps.ch/tiles/teatime"]) }); layer.addTo(map); var teapot_marker = new map3d.marker("Green Teapot", [0,0,0]); teapot_marker.addTo(map); var cube_maker = new map3d.marker("Green Cube", [80.5, 11.5, 10.5]); cube_maker.addTo(map);](https://image.slidesharecdn.com/presentationsmall-160205125512/75/3D-Computer-Graphics-with-Python-44-2048.jpg)
Uploaded byMartin Christen
3D Computer Graphics with Python
This document presents a talk on 3D computer graphics using Python, focusing on scripting with Blender and creating applications for web browsers. It covers technologies like OpenGL and Vispy for low-level APIs and highlights practical examples, including virtual globes and digital reconstructions of historical cities. The talk emphasizes the integration of 2D and 3D maps and discusses the challenges and advancements in 3D visualization.
In this document
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Introduction of Martin Christen and the Swiss Python Summit; overview of technologies in 3D graphics using Python.
Introduction to Blender, an open-source suite for 3D creation with capabilities in modeling, animation, and rendering.
Overview of Python scripting in Blender, including accessing data, creating objects, and transforming them with commands.
Demonstrates how to generate meshes programmatically with Python, including creating a tetrahedron and optimizing 3D objects.
Cleaning up and optimizing historical model involving 125,929 triangles reduced to 56,216 triangles for improved performance.
Introduction to low-level APIs, focusing on OpenGL API bindings and how graphics are rendered through shaders.
Introduction and installation of Vispy for 2D/3D visualizations, including code examples and creating a basic application.
Discussion of web-based 3D applications, streaming data, and displaying 3D scenes in browsers using concepts of 2D maps. Identifies issues with WebGL compatibility, navigation complexity, and data limitations in 3D mapping applications.
Presentation of the 3DMaps.ch project, technology for merging 2D and 3D mapping and its future developments.
Summary of three methods for using 3D graphics in Python; announcement of future meetups and a GeoPython conference.
3D Computer Graphics with Python
- 1. Martin Christen FHNW Hochschule für Architektur, Bau und Geomatik Institut Vermessung und Geoinformation martin.christen@fhnw.ch @MartinChristen 3D Computer Graphics with Python „3D Graphics the Pythonic Way“ Swiss Python Summit
- 2. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 2 About this talk In this talk several technologies around 3D graphics for Python are presented. • A brief introduction to scripting Blender shows the possibilities of creating complex 3D Worlds and games. • The second part shows how to create low level 3D applications and how Python is used to create preprocessed 3D worlds for the webbrowser.
- 3. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 3 PART I: Python and Blender What is Blender ? • Blender is a free and open source 3D creation suite for: • Modelling • Animation • Simulation • Rendering • Video Editing • Motion Tracking • Game Creation • …and more.. • Runs on Linux, MacOS and Windows
- 4. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 4 Cycles Demo Reel (2015) – All made with Blender https://www.youtube.com/watch?v=wDRTjzLNK0g
- 5. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 5 Blender Motion Tracking https://www.youtube.com/watch?v=2AvQiOf2IGA
- 6. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 6 Python Scripting in Blender Choose the Scripting View:
- 7. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 7 Python Scripting in Blender Now you see the Python 3.x console:
- 8. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 8 The first program: Accessing Data is quite simple, use the module bpy.data: list(bpy.data.objects) list(bpy.data.scenes) list(bpy.data.materials) So let’s enter the following in the Python console: >>> list(bpy.data.objects)
- 9. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 9 List of all objects in the scene: And that is pretty much what you see in the scene graph:
- 10. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 10 Python Scripting in Blender Open the Tab in the 3d View and select “Create”:
- 11. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 11 Python Scripting in Blender When you hold mouse over “Cube” you will see the Python Command how to create a cube! Just note it and click on cube.
- 12. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 12 Python Scripting in Blender When you create the cube you will see the exact command that was called to create it. You see most actions as Python code there.
- 13. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 13 Python Scripting in Blender: Adding (predefined) Objects Right click on the text (highligh) and copy the text (ctrl-c) bpy.ops.mesh.primitive_cube_add(radius=1, view_align=False, enter_editmode=False, location=(0, 0, 0), layers=(True, False, False, False, False, False, False, False, False, False, False, False, False, False, False, False, False, False, False, False)) Hit undo (ctrl-z) And now we modity the command using location=(0,3,0) and radius=2: bpy.ops.mesh.primitve_cube_add(radius=2, location=(0,3,0))
- 14. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 14 Python Scripting in Blender: Transform objects If we move the new cube by pressing and holding the blue z-Axis we can see the following command: bpy.ops.transform.translate(value=(0, 0, 3.10625), constraint_axis=(False, False, True), constraint_orientation='GLOBAL', mirror=False, proportional='DISABLED', proportional_edit_falloff='SMOOTH', proportional_size=1, release_confirm=True) That is how an object is translated
- 15. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 15 Python Scripting in Blender: Operations Apply Operations like Subdivision: bpy.ops.object.mode_set(mode='EDIT') bpy.ops.mesh.subdivide() bpy.ops.mesh.subdivide() bpy.ops.mesh.subdivide() bpy.ops.object.mode_set(mode=OBJECT')
- 16. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 16 Creating Meshes for example: Tetrahedron import bpy s = 0.5**0.5 # 0.5*sqrt(2) verts = ((s,s,-1), (s,-s,-1), (-s,-s,-1), (-s,s,-1), (0,0,1)) faces = ((1,0,4), (4,2,1), (4,3,2), (4,0,3), (0,1,2,3)) mesh = bpy.data.meshes.new("TetrahedronMesh") object = bpy.data.objects.new("TetrahedronObject", mesh) object.location = (0,0,0) # origin scene = bpy.context.scene scene.objects.link(object) scene.objects.active = object object.select = True mesh.from_pydata(verts, [], faces) # vertices, edges, faces mesh.update()
- 17. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 17 Real Life Example Using Python to optimize 3D objects: bpy.ops.object.select_all(action='DESELECT') bpy.context.scene.objects.active = bpy.data.objects[1] bpy.ops.object.select_all(action='SELECT') bpy.ops.object.join() bpy.ops.object.mode_set(mode='EDIT') bpy.ops.mesh.dissolve_limited() bpy.ops.mesh.remove_doubles(threshold=0.01) bpy.ops.mesh.select_all(action='DESELECT') bpy.ops.mesh.select_interior_faces() bpy.ops.mesh.delete(type='FACE') bpy.ops.object.mode_set(mode='OBJECT')
- 18. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 18 Historic Roman City “Augusta Raurica” – Generated with ESRI City Engine
- 19. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 19 Cleaned up: Jour, Remove Double Vertices/Faces, Interior Faces
- 20. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 20 Final Result (125’929 triangles optimized to 56’216 triangles)
- 21. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 21
- 22. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 22 PART II: Low Level APIs • OpenGL API bindings • Open Graphics Library - based on C • http://pyopengl.sourceforge.net/ • DirectPython 11: Direct3D 11 (Windows only) • http://directpython11.sourceforge.net/ • Not Cross Platform
- 23. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 23 PyOpenGL Supports OpenGL 1.1 to 4.4 Works with popular GUI libraries, for example: • wxPython • PyQT / PySide • PyGTK • PyGame • Tkinter (+ Togl widget) I‘m not going to make an OpenGL introduction here...
- 24. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 24 How OpenGL Works Primitives (=Points, Linies, Triangles) are converted to Fragments (Pixels). Program Vertex-Operations (e.g. projection, transformation). Program Fragment-Operations for shading/lighting/texturing. Vertex/Fragment Shaders [run on the GPU and] are written in GLSL.
- 25. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 25 Vispy: http://vispy.org/ ( https://github.com/vispy/vispy ) VisPy is a young library under heavy development at this time. It targets two categories of users: • Users knowing OpenGL, or willing to learn OpenGL, who want to create beautiful and fast interactive 2D/3D visualizations in Python as easily as possible. • Scientists without any knowledge of OpenGL, who are seeking a high-level, high-performance plotting toolkit.
- 26. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 26 Install vispy 1) Numpy is required 2) OpenGL is required 3) A compatible GUI Toolkit is required Then: pip install vispy More info: http://vispy.org/installation.html
- 27. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 27 Example, lets create a virtual environment named “gl” python3.5 -m venv gl source gl/bin/activate pip install vispy # also installs numpy pip install pyglet … do your stuff … Deactivate
- 28. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 28 Development Version (currently 0.5.0.dev0) git clone git://github.com/vispy/vispy.git cd vispy python3.5 setup.py develop (Only this version support Jupyter Notebook!)
- 29. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 29 Windows on Windows, download modules* from: http://www.lfd.uci.edu/~gohlke/pythonlibs *) vispy, numpy & pyglet
- 30. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 30 Our first App import sys from vispy import app, gloo canvas = app.Canvas(app='pyglet', keys='interactive', size=(800, 600)) @canvas.connect def on_draw(event): gloo.set_clear_color((1.0, 0.0, 0.0, 1.0)) gloo.clear() canvas.show() if __name__ == '__main__': app.run()
- 31. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 31 Use Shaders, Geometry
- 32. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 32 Jupyter Notebook (WebGL Output)
- 33. • Virtual Globeusing WebGL • Open Source Project started in April 2011 • JavaScript Library for rapid developmentof web-based geospatial 3D applications • Data Processing in Python 332.5.2016 33 Python for Data Processing Institute of Geomatics Engineering
- 34. 2.5.2016Institute of Geomatics Engineering 34 Demo
- 35. 2.5.2016Institute of Geomatics Engineering Streaming 3D-Geometry Tiles MapData © OpenStreetMap contributors 35 BTh Hürbi/Daetwyler, MTh Lucas Oertli, 2013
- 36. 2.5.2016Institute of Geomatics Engineering 36 Streaming Example: 3D Geometry using OSM and “BOI” (worldwide streaming) MTh Lucas Oertli, 2013
- 37. 2.5.2016Institute of Geomatics Engineering 37 Streaming Example: Osnabrück (local streaming) Created by Geoplex with Plexmap, based on OpenWebGlobe
- 38. 2.5.2016Institute of Geomatics Engineering 38 Some Problems I have with (Web-Based) Virtual Globes • Unfortunately, WebGL compatibility is still an issue… a “fallback” is required • Most people still prefer 2D Maps • Navigation in 3D is too complicated for many users… • In the “Geo-World”, 3D Models are usually not built by 3D game designers: • Often there are “too many” & “too big” textures per object • Different details per 3D-object • Remember “Google 3D Warehouse” • Level of Detail: Generalization in 2D is accepted, but not in 3D! • Limited number of people actually do have data of the whole world… • Most virtual globe based applications I know are limited to a certain region/country/… • Too slow (bandwidth/3D rendering) on mobile devices • Too power consuming on mobile devices
- 39. 2.5.2016Institute of Geomatics Engineering 39 Bringing together 2D Maps and 3D Globes Concept: Prerender a 3D Scene using a high quality offline 3D renderer using an orthographic projection and create “2D” image tiles. Constant, minimal bandwidth regardless of the complexity of the 3D city model MTh Markus Jung, 2014 (Similar approaches were already done by Döllner et al. and also go back to some concepts by Sutherland)
- 40. 2.5.2016Institute of Geomatics Engineering 40 Display in the Webbrowser as “2D Map” MTh Markus Jung, 2014
- 41. 2.5.2016Institute of Geomatics Engineering 41 Display in the Webbrowser as Panorama MTh Markus Jung, 2014
- 42. 2.5.2016Institute of Geomatics Engineering 42 High Resolution Geometry doesn’t matter: Same download/render speed MTh Markus Jung, 2014
- 43. 2.5.2016Institute of Geomatics Engineering 43 The 3dmaps.ch Project: Bringing it all together! 3DPS (3D Portrayal Service)
- 44. 2.5.2016Institute of Geomatics Engineering 44 Viewer API map3d.js Library var map = new map3d.map("mapcanvas"); var layer = new map3d.imageLayer([ "http://t1.3dmaps.ch/tiles/teatime", "http://t2.3dmaps.ch/tiles/teatime", "http://t3.3dmaps.ch/tiles/teatime", "http://t4.3dmaps.ch/tiles/teatime"]) }); layer.addTo(map); var teapot_marker = new map3d.marker("Green Teapot", [0,0,0]); teapot_marker.addTo(map); var cube_maker = new map3d.marker("Green Cube", [80.5, 11.5, 10.5]); cube_maker.addTo(map);
- 45. 2.5.2016Institute of Geomatics Engineering 45 Different prerenderings for different pitch/view direction Every Prerendering needs storage, but with todays cloud storage pricing this is not really an issue anymore!
- 46. 2.5.2016Institute of Geomatics Engineering 46 Why a teapot if we have (open) Geo Data ?!! Use case 1: Rotterdam Dataset 90 CityGML files with a total size of 2.72 GB 26'474 textures with a size of 1024x1024, an uncompressed total data volume of around 77 GB Orthophoto uncompressed 430 GB
- 47. 2.5.2016Institute of Geomatics Engineering 47 Use case 2: The Roman city of Augusta Raurica A digital reconstruction of the historical Roman City of Augusta Raurica, created at the institute of Geomatics Engineering at the FHNW. 3D-Printed to create a bronze model.
- 48. 2.5.2016Institute of Geomatics Engineering 48 The 3D Model About 4000 geospatial objects (buildings, roads, vegetation features, terrain, …) at three levels of detail. 3D Geometry & Textures around 1 GB
- 49. 2.5.2016Institute of Geomatics Engineering 49 Prerendering the Model: Color Map, Normal Map, Id-Map, Depth Map Dynamic Lighting Normal Map: for Object Identification: Highlighting, special effects, … Depth Map: for 3D Position, special effects, …
- 50. 2.5.2016Institute of Geomatics Engineering 50 3D View in the (mobile) webbrowser with dynamic Lighting
- 51. 2.5.2016Institute of Geomatics Engineering 51 The Viewer • The viewer basically uses the same concepts as a “2D Map Viewer” • map3d.js supports WebGL There is also a pure canvas version available as fallback • Operations like “highlighting” are highly customizable. Basically it is an image processing operation which runs on the GPU (WebGL Version). If there is no WebGL available, the operation is done using JavaScript.
- 52. 2.5.2016Institute of Geomatics Engineering 52 Outlook (1) • Implement more effects and lighting models, dynamic snow/water/etc. using depth map & normal map • Layer management (include point clouds, mix different layers using depth map • Add realtime content (“mix real 3D Object”) using depth-map • Release map3d.js as Open Source (around Q2/2016)
- 53. 2.5.2016Institute of Geomatics Engineering 53 Outlook (2) More Rendering Effects, for example Screen Space Ambient Occlusion (SSAO) BTh, Daniel Rettenmund 2015
- 54. 2.5.2016Institute of Geomatics Engineering 54 Outlook (3) • “isometric maps” will be one of many features of OpenWebGlobe 2 • “isometric maps” will be the default 3D Viewer in OpenWebGlobe 2 • Switch to “real 3D” anytime • State is saved: • The best matching viewpoint is selected when switching • If you highlight an object in “isometric mode”, it will be highlighted in “Real 3D” mode too.
- 55. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 55 Conclusion 3 ways to use 3D Graphics in Python were presented: 1. Using Python & Blender (including Blender Game Engine) 2. Using Low a Level API (OpenGL/WebGL) 3. Using Python to process 3D Views Which approach is the best for Python ? This really depends the application domain. I am quite sceptic with 2. - If you want to create a complex 3D game, I don’t recommend using Python at this time. I believe Python is great for 1. and 3.
- 56. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 56 Next Meetup: February 9th, 2016 in Muttenz (near Basel) 18:00 to 21:00 http://www.pybasel.ch
- 57. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 57 1st GeoPython Conference http://www.geopython.net
- 58. Swiss Python Summit, February 5, 2016Institut Vermessung und Geoinformation 58 Q&A