sam hocevar
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 Nov 2 comment How can I compute the common points when spheres intersect? @wrangler they are just temporary variable names, to make the whole thing slightly more readable. They do not mean anything in particular. Oct 24 comment How do I efficiently check if a point is inside a rotated rectangle? Do you have many points, or do you have many rectangles? That’s the first question you should ask yourself before you try to optimise such a small task. Oct 21 comment Get all points of a parabola In all honesty I think there’s a mistake somewhere in your code, because I’m pretty sure about the maths. To render the graphs I used Gnuplot with the following commands: paste.debian.net/317369 Oct 18 comment Get all points of a parabola Double check your code. sqrt() should return 0.912870929175277, not 0.92582009… Oct 18 comment Get all points of a parabola Ah, but then Cy is smaller than Ay and By, so it’s no longer a “jump” above an object. If your Y axis goes downwards, you’ll need to use `k = -sqrt(…)` instead of `k = sqrt(…)`. Also, check your code, because with the formulas above you should get `k=0.912870929175277`. Oct 17 comment Get all points of a parabola Please be more specific. Give the values for Ax, Ay, Bx, By, C.y, and what you get for k, u and v. Otherwise it’ll be difficult to tell what’s wrong. Sep 4 comment What happens if I make more than \$100k with the free Unity license? I'm voting to close this question as off-topic because you’d better ask a Unity salesperson directly. Jul 24 comment How do I lerp between values that loop (such as hue or rotation)? @GustavoMaciel having checked the code again, it’s actually extremely safe and works exactly as it should even in the corner case you describe. Jul 24 comment How do I lerp between values that loop (such as hue or rotation)? @GustavoMaciel that’s not “most cases”, that’s one very specific corner case that just never happens in practice. Also, there is no division by zero, check the code. Jul 20 comment Why is the drag force multiplied by the inverse normalised velocity vector? But you can’t do it component-wise; this is only valid for linear operations, and the `v²` in the drag formula makes it non-linear. Just compare the results you get with `v` = `[1 0 0]` and with `[0.8 0.6 0]`. Both these vector have unit length, but your method will give you 30% less drag with the second vector. Jul 7 comment Correct way to integrate scaled axis angular velocity into a quaternion “Both approaches produce a rotation” really? The second method does not produce a unit quaternion in general, but since you say it’s from a reputable source there must be a lot of missing information in your question. Jun 15 comment Transform Matrix multiplication order The confusion comes from the fact that you are talking about local transformations (where the frame remains linked to the object), whereas the transformations described here happen in world space (where there is only one fixed reference frame, the world). Conceptually, your way of seeing things is valid, and it is equivalent to applying transformations in reverse order. May 16 comment Finding which tiles are intersected by a line, without looping through all of them or skipping any possible duplicate of How do I generalise Bresenham's line algorithm to floating-point endpoints? (the question isn’t actually about Bresenham) May 5 comment Algorithm that always returns the same pseudorandom output if given the same input of seed, x and y? I have posted the code. Maybe refresh the page? But, anyway, your stubbornness is hopeless and your objections indicate that there are too many things you don’t understand and you should either read about them or trust the people who do. If after so much information has been given to you, you still “don't need to measure”, well you’re just not the kind of person I want to help; hopefully my answer can still be useful to someone else. Have fun! May 5 comment Algorithm that always returns the same pseudorandom output if given the same input of seed, x and y? @NovaCrist Gee, that C++ code is 5 times faster than MurmurHash3. I’m pretty sure you actually didn’t measure anything. May 5 comment Algorithm that always returns the same pseudorandom output if given the same input of seed, x and y? You just do not seem to understand how a PRNG is a hashing function, and how a PRNG can be fast. Seriously, learn to listen to advice from professional developers who know their stuff. Don’t dismiss suggestions based on an “overhead” you didn’t measure. I edited my answer with a C++ implementation; it’s three lines of code; it’s a proven algorithm; it can be trivially adapted to 2 or 4 or 30 variables instead of 3 depending on your requirements. Unless you have a real reason, you should use established, available standards instead of rolling custom code you’ll have to debug and maintain. May 4 comment Algorithm that always returns the same pseudorandom output if given the same input of seed, x and y? @NovaCrist There is nothing wrong with “shuffling around values”, that’s someting most PRNGs and hashing algorithms have in common. You use words like “categorically”, “unsuitable”, “approximate”, “silly”, but are you sure you fully grasp the concepts you are tackling? If you are getting artifacts with the method I suggest, you are doing someting wrong, because it’s a mathematically correct solution to your problem. See for instance this code which I used to generate this image. Apr 28 comment Java OpenGL Perspective matrix not working It’s not particularly “incorrect”. It’s probably preferable to have an explicit constructor `mat4(1.0)` for this anyway. Apr 27 comment How can I go about testing games on a console UE4 does not support the PS3. Did you mean PS4? If so, you’d still need a PS4 test kit, and yes, that whole registration thing… but maybe your best bet would be to make friends with someone who has access to a test kit :-) Apr 7 comment Algorithm that always returns the same pseudorandom output if given the same input of seed, x and y? Dude, this is pseudocode. As I said, just use a different PRNG if you don’t like `rand()`.