485 reputation
26
bio website mathandcode.com/portfolio
location
age 20
visits member for 2 years, 5 months
seen Mar 30 at 17:13

Jan
31
answered How do I use the dot product to get an angle between two vectors?
Dec
20
comment Why not use vectors to represent orientation?
@slartibartfast I believe so, but there's a difference between "Add these two 3D angular velocities" and "rotate by this angular velocity for A seconds and then rotate by this angular velocity for B seconds".
Nov
5
awarded  Yearling
Oct
16
revised The physics equation for a perpetual seesaw
added 136 characters in body
Oct
16
comment The physics equation for a perpetual seesaw
@teodron I made it nicer, let me know. No shorter, but I did delete some paragraphs and format it. I don't see how energy/force equations would make things nicer here: as I see it to use more force things you'd need a bunch of collision detection and conditional statements, and to use energy equations you'd need to do the same thing as above, while making up values for energy loss and dealing with qdt squared instead of just qdt.
Oct
16
revised The physics equation for a perpetual seesaw
Made it nice.
Oct
16
revised The physics equation for a perpetual seesaw
added 263 characters in body
Oct
16
answered The physics equation for a perpetual seesaw
Aug
16
comment Can I simplify the inequality “distance(p1, p2) < distance(p1, p3)?”
@SamHocevar Sure, I agree, but what does that have to do with points and vectors? ;)
Aug
15
comment Can I simplify the inequality “distance(p1, p2) < distance(p1, p3)?”
You have four additions, so 4*dimension additions total. I'm not sure what's better: d more multiplications or 2*d more additions? I think this is an unsatisfactory answer; what Byte56 did is straightforward, and this doesn't even leave me convinced that it's any faster! (Also, if we don't care about the distinction between affine spaces and vector spaces, insisting that vectors and points are distinct only gets in the way of understanding. Personal opinion/peeve.)
Feb
9
comment Optimizing gravity calculations
And I should add: I don't have the source code. If you're looking for some source code check out part-nd (written in c). I'm sure there are others out there, too.
Feb
9
comment Optimizing gravity calculations
Fixed! sorry, forgot to pay the rent on that domain, and someone auto-bought it :\ Also, 3 mins is a pretty good response time on a 1.3 year old post 8D
Feb
9
revised Optimizing gravity calculations
fixed dead link & added video
Nov
5
awarded  Yearling
Apr
13
comment Is knowing physics necessary for game development?
world coordinate to screen coordinate transformations, composition of matrices so that objects can be fixed relative to each other (limbs). Really anything to do with translating, scaling, or rotating objects (especially doing all three at once). Besides affine linear algebra, there's also dot product, useful for anything "in the direction of" anything else (shooting, turning, pointing). Linear algebra is also what turns a 3d object into a 2d point on your screen (1 matrix+1 division=point on screen!)
Apr
11
comment Is knowing physics necessary for game development?
+1 for vectors. Linear algebra and affine transformations are extremely useful for simplifying equations.
Apr
5
answered How do I find the angle required to point to another object?
Apr
5
awarded  Critic
Apr
5
comment How do I find the angle required to point to another object?
Sorry to burst your bubble, but this method is 100% equivalent in theory to his method IF you subtract the camera's angle from his result.mathbin.net/91914
Apr
5
comment How do I find the angle required to point to another object?
You'd have to use the actual value of the cross product, because the length of a vector can't be negative (so if sin(theta) is negative the equation breaks down). Since A and B are on the same 2d plane, AxB has a Z component but an X and Y component of zero. So the Z component is sin(theta) WITH the sign. No length-taking necessary.