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Lecture Series for Those Who Stay Home

World of 3D Optical Illusion

 Many people are fighting against the new coronavirus, but I cannot do anything except for just staying home. So I decided to start this series of lectures of 3D optical illusion with the hope that they could entertain those who stay home. It is my pleasure if you could enjoy them. (Related links are here.)

One general remark is that seeing videos is quite different from seeing 3D objects directly. When we see objects directly, we can use two eyes and hence can understand the depth relatively easily. On the other hand, seeing videos is essentially equivalent to seeing objects by one eys, because a video camera has only one lens center. Some of the illusions presented here do not occur when we see the objects directly. Anyway you may enjoy all of the illusions as long as you are watching the videos. [April 4, 2020]

In this series of lectures from 1 to 18 (except for Lecture 6), I showed my own theories together with my own illusion artworks. In Lecture 6, Lecture 19 and afterward, on the other hand, we choose general topics on 3D optical illusion that are known in this research area. In those cases also I use original material that I create myself. [July 28, 2020]


Lecture 1. Right-Facing Arrow
　　　Comments on Lecture 1
　　　Gallery of Facing-Right Objects



Lecture 2. Anti-Gravity Slopes
　　　Comments on Lecture 2
　　　Gallery of Anti-Gravity Slopes



Lecture 3. Height-Reversing Staircase
　　　Comments on Lecture 3
　　　Gallery of Height-Reversing Staircases



Lecture 4. Penrose Triangle
　　　Comments on Lecture 4
　　　Gallery of Anomalous Objects



Lecture 5. Circular Rectangle
　　　Comments on Lecture 5
　　　Gallery of Ambiguous Objects Made by Circular Rectangles



Lecture 6. Multiple Silhouette Objects
　　　Comments on Lecture 6
　　　Gallery of Multiple Silhouette Objects



Lecture 7. Height-Reversing Objects
　　　Comments on Lecture 7
　　　Gallery of Height-Reversing Objects



Lecture 8. Invisible Chicken
　　　Comments on Lecture 8
　　　Gallery of Partly Invisible Objects



Lecture 9. Ambiguous Cylinders
　　　Comments on Lecture 9
　　　Gallery of Ambiguous Cylinders



Lecture 10. Topology-Disturbing Objects
　　　Comments on Lecture 10
　　　Gallery of Topology-Disturbing Objects



Lecture 11. Card Marks Floating on a Mirror
　　　Comments on Lecture 11
　　　Gallery of Reflexively-Fused Objects



Lecture 12. Paper-Made Ambiguous Cylinders
　　　Comments on Lecture 12
　　　Gallery of Paper-Made Ambiguous Cylinders



Lecture 13. Ambiguous Tiling
　　　Comments on Lecture 13
　　　Gallery of Ambiguous Tiling



Lecture 14. Triply Ambiguous Objects
　　　Comments on Lecture 14
　　　Gallery of Triply Ambiguous Objects



Lecture 15. Ambiguous Objects with Six Interpretations
　　　Comments on Lecture 15
　　　Gallery of Ambiguous Objects with Six Interpretations



Lecture 16. Impossible Motion
　　　Comments on Lecture 16
　　　Gallery of Impossible Motion



Lecture 17. Figure Construction Methof for Ambiguous Objects
　　　Comments on Lecture 17



Lecture 18. Ambiguety with Shadows
　　　Comments on Lecture 18
　　　Gallery of Ambiguety with Shadows



Lecture 19. Depth Reversal Illusion
　　　Comments on Lecture 19




Lecture 20. How to Draw Impossible Figures
　　　Comments on Lecture 20




Lecture 21. Pictures That Stand Up
　　　Comments on Lecture 21




Lecture 22. Viewpoint Trick
　　　Comments on Lecture 22




Lecture 23. Classical Illusion Caused by Depth Perception
　　　Comments on Lecture 23
　　　Gallery of classical illusion caused by depth perception



Lecture 24. Illusions That Might Be Caused by Depth Perception
　　　Comments on Lecture 24
　　　Gallery of illusions that might be caused by depth perception