Reflecting Vectors

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Previous: 'The Equations of Motion'

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00:33Importance of vector math

00:33Importance of vector math

00:33Importance of vector math

02:09Recap of last episode

02:09Recap of last episode

02:09Recap of last episode

03:36On the homogeneity of scalar and vector math notation

03:36On the homogeneity of scalar and vector math notation

03:36On the homogeneity of scalar and vector math notation

05:45Goal for today: bouncing off of walls

05:45Goal for today: bouncing off of walls

05:45Goal for today: bouncing off of walls

07:06Blackboard diagram of expected bouncing behavior

07:06Blackboard diagram of expected bouncing behavior

07:06Blackboard diagram of expected bouncing behavior

07:47Axis-aligned vector reflection

07:47Axis-aligned vector reflection

07:47Axis-aligned vector reflection

12:26General-case vector reflection

12:26General-case vector reflection

12:26General-case vector reflection

15:02The inner/scalar/dot product

15:02The inner/scalar/dot product

15:02The inner/scalar/dot product

23:41Applications of the inner product: vector length

23:41Applications of the inner product: vector length

23:41Applications of the inner product: vector length

27:15Applications of the inner product: measurement of vectors on new reference frames

27:15Applications of the inner product: measurement of vectors on new reference frames

27:15Applications of the inner product: measurement of vectors on new reference frames

34:22Solving general reflection using the inner product

34:22Solving general reflection using the inner product

34:22Solving general reflection using the inner product

40:24Implementing the solution

40:24Implementing the solution

40:24Implementing the solution

43:22Placeholder code to detect orientation of colliding walls

43:22Placeholder code to detect orientation of colliding walls

43:22Placeholder code to detect orientation of colliding walls

49:19Short comment on loss of energy and coefficient of restitution

49:19Short comment on loss of energy and coefficient of restitution

49:19Short comment on loss of energy and coefficient of restitution

50:25Challenge to the stream: how do you run along the wall?

50:25Challenge to the stream: how do you run along the wall?

50:25Challenge to the stream: how do you run along the wall?

51:51Answer to the challenge

51:51Answer to the challenge

51:51Answer to the challenge

53:28Discussion on sticky behavior

53:28Discussion on sticky behavior

53:28Discussion on sticky behavior

58:13Q&A

🗩

58:13Q&A

🗩

58:13Q&A

🗩

59:31Can you explain again why the hero was sticking against the wall?

59:31Can you explain again why the hero was sticking against the wall?

59:31Can you explain again why the hero was sticking against the wall?

1:02:43When do we scale down the hero?

1:02:43When do we scale down the hero?

1:02:43When do we scale down the hero?

1:03:11Have you considered using sin(0) to sin(90) as a non-linear inertia curve?

1:03:11Have you considered using sin(0) to sin(90) as a non-linear inertia curve?

1:03:11Have you considered using sin(0) to sin(90) as a non-linear inertia curve?

1:03:51Will you eventually handle player and monsters in some kind of physics engine?

1:03:51Will you eventually handle player and monsters in some kind of physics engine?

1:03:51Will you eventually handle player and monsters in some kind of physics engine?

1:04:32Do you need to code in different collision detection for the enemies?

1:04:32Do you need to code in different collision detection for the enemies?

1:04:32Do you need to code in different collision detection for the enemies?

1:05:09Will you add comments to the source for those who preordered?

1:05:09Will you add comments to the source for those who preordered?

1:05:09Will you add comments to the source for those who preordered?

1:05:45Do you plan on having non axis-aligned walls in the maps?

1:05:45Do you plan on having non axis-aligned walls in the maps?

1:05:45Do you plan on having non axis-aligned walls in the maps?

1:07:12What do you think about position based dynamics?

1:07:12What do you think about position based dynamics?

1:07:12What do you think about position based dynamics?

1:08:42Are we going to do continuous collision detection?

1:08:42Are we going to do continuous collision detection?

1:08:42Are we going to do continuous collision detection?

1:09:08Is the computational cost of functions something you only learn by experience?

1:09:08Is the computational cost of functions something you only learn by experience?

1:09:08Is the computational cost of functions something you only learn by experience?

1:11:08Will you end up in problems when walking into corners after the sticking fix tomorrow?

1:11:08Will you end up in problems when walking into corners after the sticking fix tomorrow?

1:11:08Will you end up in problems when walking into corners after the sticking fix tomorrow?

1:11:27Will there be a minimum distance to the wall?

1:11:27Will there be a minimum distance to the wall?

1:11:27Will there be a minimum distance to the wall?

1:12:03Will computing a vector where the player will stop just before the wall solve the sticking?

1:12:03Will computing a vector where the player will stop just before the wall solve the sticking?

1:12:03Will computing a vector where the player will stop just before the wall solve the sticking?

1:13:13Additional explanation to the bounce vector calculation

1:13:13Additional explanation to the bounce vector calculation

1:13:13Additional explanation to the bounce vector calculation

1:19:25Is there a way to speed up the DrawBitmap code?

1:19:25Is there a way to speed up the DrawBitmap code?

1:19:25Is there a way to speed up the DrawBitmap code?

1:21:15Suggestion to remove reblitting the background to improve performance

1:21:15Suggestion to remove reblitting the background to improve performance

1:21:15Suggestion to remove reblitting the background to improve performance

1:22:08Stream notes Casey drew the cos/sin triangle wrong

1:22:08Stream notes Casey drew the cos/sin triangle wrong

1:22:08Stream notes Casey drew the cos/sin triangle wrong

1:23:39A wish to mention formal keywords to help people look things up

1:23:39A wish to mention formal keywords to help people look things up

1:23:39A wish to mention formal keywords to help people look things up

1:24:53Was the Witness collision trick to try maintain the distance traveled?

1:24:53Was the Witness collision trick to try maintain the distance traveled?

1:24:53Was the Witness collision trick to try maintain the distance traveled?

1:25:21Why does wall bouncing not seem to cause sticking, but sliding does?

1:25:21Why does wall bouncing not seem to cause sticking, but sliding does?

1:25:21Why does wall bouncing not seem to cause sticking, but sliding does?

1:27:06Stream mentions KhanAcademy for learning math

1:27:06Stream mentions KhanAcademy for learning math

1:27:06Stream mentions KhanAcademy for learning math

1:27:20Will the rendering code be able to squash bitmaps?

1:27:20Will the rendering code be able to squash bitmaps?

1:27:20Will the rendering code be able to squash bitmaps?

1:28:01Could you/would you benefit from unrolling the collision loop ... ?

1:28:01Could you/would you benefit from unrolling the collision loop ... ?

1:28:01Could you/would you benefit from unrolling the collision loop ... ?

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Next: 'Geometric vs. Temporal Movement Search'

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