78 reputation
18
bio website blog.megastructure.org
location Israel
age 31
visits member for 4 years, 4 months
seen Aug 2 '12 at 15:22

Dec
15
awarded  Notable Question
Jan
24
awarded  Popular Question
Sep
8
awarded  Commentator
Sep
8
comment How to take into consideration the effect of initial rotation of a ball hitting & reflecting off a surface
you may have to take masses into account here. Two balls of different masses spinning at the same rate will react differently when hitting a static wall - the lighter ball will be more affected by the spin. In your example, conservation of energy should hold, this includes energy from moment of inertia.
Sep
3
comment How do some games save without creating data files?
On Windows Vista or 7, elevated privileges are needed in order to modify files in the Program Files directory. It is reasonable to run an installer as admin, but running the executable as a normal user will not allow this type of modification. (Just strengthening AttackingHobo's comment.)
Aug
26
comment Solids as high viscocity Liquids
I love the idea of having the world slowly melt.
Aug
15
comment Combine n Gaussian Probability Sets in a limited float range
How are your Gaussians defined? Do you have a numerical function, or is it the parameters of a regular Gaussian (mean, variance)? I would also like clarification of "no divisible slice", and what this has to do with solution spaces.
Aug
10
awarded  Editor
Aug
10
revised How do I calculate rotation caused by bounce friction?
added a more robust way to calculate the direction of impact, using the incident and normal vectors.
Aug
10
comment How do I calculate rotation caused by bounce friction?
How do you take into account the original spin of the ball? If it is rotating very fast, it might launch itself away in a totally different direction. The problem with dot-product in your case is that it uses the cosine (an even function). You need something else to set the sign of the relationship between your vectors (incident and normal). You can use a cross-product (vector product) for this purpose. I have edited my answer to include a cross-product method.
Aug
10
answered How do I calculate rotation caused by bounce friction?
Aug
3
awarded  Scholar
Aug
3
comment Non-destructive way to edit alpha channel in Photoshop/Gimp image
This was exactly what my problem was. I was outputting to PNG and not seeing any of the "alpha" channel goodness. Thanks, this is perfect. Does anyone have instructions for using the Gimp similarly?
Aug
3
accepted Non-destructive way to edit alpha channel in Photoshop/Gimp image
Aug
3
answered How to prepare for a game development competition?
Aug
3
awarded  Student
Aug
3
comment Non-destructive way to edit alpha channel in Photoshop/Gimp image
This is closer to what I need. But it only affects the top layer! I have multiple layers in my image, and I would like to be able to do this without flattening it. Thanks for answering.
Aug
3
comment Non-destructive way to edit alpha channel in Photoshop/Gimp image
it looks like I have to flatten the image first, then decompose, then edit, and then recompose. Thanks for the tip! But I'm looking for a non-destructive way.
Aug
3
asked Non-destructive way to edit alpha channel in Photoshop/Gimp image
Jul
17
awarded  Critic