Your original post was incorrect, skydiving is not actually freefall, infact it is nothing like it. Although it is often called that, the force of air constantly acts on the participant. Other people correctly described why it is acceptable to call this zero-G and gave descriptions of why that have been generally accepted as a description of the phenomenon and you foolishly tried to correct them. Your subsequent posts attempted to correct physically accurate descriptions because they use commonly accepted terms for this like zero gravity (and micro gravity), are misguided. This is zero gravity in the frame of reference of the aircraft.
What you should realize is that when ISVs encounter the typical Mac mailbomb campaign and flamage they quickly learn that it is something they want to avoid. The irrational tirades of the loyal legions just plane scare developers away. Even developers who want to throw a bone to the Mac community find that it ain't worth the hastle feeding a beast that seems to think it's entitled to take your hand off. The ISV I used to work for was subjected to this kind of insanity because a pundit suggested a port was in the offing, we were immediately mailbombed by legions of rabbid crazy people that put Slashdot Anonymous Coward posts to shame. Even the more legible posts were profoundly foolish suggesting business justifications and citing the "huge mac installed base" with not a single fact to back up vague assertions. Folks in the office just laughed at this tripe, in short the Mac community made a horses ass of itself. Your hatred of Real as one of the ISVs that does support your platform just illustrates that same attitude. Unfortunately it's just much better for ISVs to ignore the Mac and avoid the flamage.
You have a profoundly flawed understanding of physics. The only difference falling in a plane and falling in an orbiting spacecraft is the air friction. The orbiting spacecraft misses the Earth thanks to it's velocity. The aircraft in this case counterracts the forces on air friction *nothing else*. So you're as weightless as you would be in space, and in fact it is *exactly* like an orbit in a physical sense when you're inside the plane.
They are different experiences, when you skydive you never feel weightlessness, you exit the aircraft and the rush of air from your forward motion exerts a lot of acceleration force (deceleration) on you then this eventually becomes the force of air pushing you up against gravity as you eventually fall faster and more vertically at your terminal velocity.
Even jumping from a stationary platform like a balloon you only feel weightless for a few seconds as your velocity builds up.
People do get sick skydiving, but it is usually on the aircraft that it affects them the most, so it is probably fair to call this common air sickness. It is an interesting fact that the terminal velocity of vomit is less than the terminal velocity of a skydiver, so if you are sick in the air it 'falls up' relative to your position. Experienced Tandem skydivers have all learned this the hard way with queezy customers.
This is very different from skydiving and very similar to orbital flight. With typical skydiving you never actually feel a lack of acceleration force. The point is the box in this case has control surfaces and flies a parabolic arc to counter the forces of air friction, all forces of air friction are removed, and in the frame of reference inside the aircraft gravitational forces don't manifest as a perceived phenomenon. What do you think an Orbit is? It's a vehicle falling under gravity and missing the Earth because of it's velocity vector (in the Newtonian model), the two differences between this and an orbital flight are the control surfaces (and engines) on the vehicle eliminating the forces of air and the fact that the arc of motion intersects the Earth. If you call orbital flights zero-G then you should call this flight zero-G because the relevant difference air friction is eliminated with by the aircraft.
Skydiving when you exit the plane you immediately feel the force of air blasting you from the direction of flight, the speed of the aircraft is enough that this force is some significant portion of 1G, it actually feels like you're falling sideways once you're used to skydiving, skydivers call this "the hill". Eventually as you fall the forward motion is eliminated as you accelerate downwards but again it just feels like the vector from which the air is pushing you has changed. From then on you're lying on a cushion of air with a full 1G of gravity, and you feel this. Skydivers do seek the thrill of weightlessness by jumping from relatively stationary platforms, like Helicopters or Hot Air Balloons, unlike normal skydiving from an moving plane you get that lump in your throat "I'm falling" feeling for a few seconds at the start of the jump. Same with BASE jumping.
It's also worth noting that receivers have a **DISH**, this basically makes required power levels for decent reception considerably less. You're not sticking rabbits ears, you're collecting a signal over the area of the surface of the dish and reflecting & focusing it towards the receiver. Moreover the satellite has a dish too that basically does the opposite with the transmitter, meaning that almost all its transmission power is directed Earthward, not randomly transmitted unlike a typical terrestrial station. So we're not really comparing apples with apples here.
Just so you get a chance to see this reply, that.plan ref was an example not a claim as to what you were referring to, that should have been clear from my later mention of a citation. Now that I've seen the quakecon video I can see he was complaining about the pixel buffers for next generation game. ONE feature and a legacy one, mainly for performance issues w.r.t. the context switch and a feature that OpenGL has had since before D3D existed. *everyone* knows this is an issue including me, if you'd read the other threads or opengl.org you'll see it discussed at length. He was expressing frustration at the intransigence of the ATI & NVIDIA engineers not compromising on the spec, not saying he would seriously go D3D. This extension has been knocked around for ages by ATI & NVIDIA and since they can't agree they're now going to push out a less ambitious render to texture spec. In other words, move along there's nothing to see.
FWIW I never said it was the original.plan just raise that as an example. Now that I've seen the quakecon video he was complaining about the pixel buffers for next generation game. ONE feature and a legacy one, mainly for performance issues w.r.t. the context switch and a feature that OpenGL has had since before D3D existed. *everyone* knows this is an issue including me, if you'd read the other threads or opengl.org you'll see it discussed at length. He was expressing frustration at the intransigence of the ATI & NVIDIA engineers not compromising on the spec, not saying he would seriously go D3D. This extension has been knocked around for ages by ATI & NVIDIA and since they can't agree they're now going to push out a less ambitious render to texture spec. In other words, move along there's nothing to see.
Ahh.... so something you don't agree with or can't see equates to rampant speculation reguardless of the foundation. Your POV does not make my post speculation.
I already know this but it's off the table now. They have postponed the uber buffers extensions and are going for a simpler render to texture extension, they could not reach agreement. Yes you can use pbuffers but they are going for a cleaner (possibly more powerful) extension.
How is this troll, *both* statements are 100% true, Lucas fired the original editor as mentioned in the film and Star Wars *DID* win an oscar for Best Film Editing in 1997, who the heck is moderating this?
What ignorant moron modded this as flamebait. If you don't understand the discussion then stay the heck away from moderating posts. Geeze!
Re:Why no comparison with D3D?
on
OpenGL 2.0 Released
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· Score: 3, Informative
You seem to be very confused. XBOX is basically a GeForce3 system with some extra vertex processors, yes it supports D3D but your assumptions about APIs are wrong. NVIDIA actually extended D3D on the XBOX with a few OpenGL like features that don't even exist today on Windows versions of D3D. So rather than D3D giving hardware the advantage it holds developers back, in a situation where hardware developers are free to extend (as they can with OpenGL) they do and bring innovative hardware features to developers early. In the unique case of the XBOX NVIDIA actually threw in a few extra functions they'd always wanted to expose on Windows D3D but couldn't because D3D didn't let them. With the shackles off on XBOX they did.
The only reason D3D is the API on XBOX is a Microsoft business decision, technical merits have nothing to do with it.
Learn DX or D3D? You do know that D3D is discontinued and Avalon is the replacement so what will it look like? I personally suspect they'll clean up D3D and it may wind up looking a lot different. The graphics scheduling, and resource/context management will obviously be a major issue/headache.
As for OpenGL, OpenGL|ES will have way more volume than longhorn units shipped, it will be on every mobile device. So I could justifiably claim that if you don't learn OpenGL|ES now you will be left behind, but I'd never say anything so silly.
Cross platform compatability is often a major goal but it depends on your project and what you're developing. Let's be clear, the hardware details and graphics programming requirements tend not to change from platform to platform, so OpenGL suitability is not compromised by it's cross platform support, it just happens to be supported on many platforms. Hardware acceleration and consistent implementation are the primary design goals of OpenGL and it succeeds spectacularly well. Implying that because it is cross platform it is somehow compromised ignores the fact that the only reason D3D is single platform (or even exists for that matter) is Microsoft's proprietary control of the market.
Re:Why no comparison with D3D?
on
OpenGL 2.0 Released
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· Score: 0, Flamebait
It's true that uber-buffers as proposed would be very general and very flexible, this is the holdup, but there's a strong case for not holding up needed features when your spec doesn't match current implementations, that's the heart of the problem.
Re:Why no comparison with D3D?
on
OpenGL 2.0 Released
·
· Score: 5, Insightful
Heh, spoken like someone who has never written a line of graphics code in their life. If you read Carmack's original OpenGL.plan you'll see that he was talking about how much cleaner OpenGL was to call.
You don't cite a reference w.r.t OpenGL & Carmack, it is clearly FUD. The only dissatisfaction I've seen from Carmack was in the Cg vs glslang hardware abstraction, I won't explain it, it's too technical for you but basically Carmack was advocating the futureproof open aproach and in some respects he got his way, however Doom3 calls ARBfp and ARBvp shaders anyway.
Carmack has never waivered from his OpenGL support and the only issue he's taken a public stand on in the API was as I said, shaders where he expressed a dislike for Cg and Cg is very similar to HLSL in D3D so Carmack was taking a stand against a shader approach that is used in D3D.
OpenGL has been around longer than D3D, is a lot cleaner in design, it has a clear unambiguius specification and has conformance tests to ensure quality of implementation. OpenGL is also portable to non-Windows platforms. All of these are excellent reasons to use OpenGl that have nothing to do with being non-Microsoft.
Your final sentence describes OpenGL better than it does D3D or are you in the habit of making random function calls to enable state you are not interested in using? There are vestigal parts of OpenGL, but they pose little implementation burden and are accelerated on high end cards where major CAD and DCC applications support them, really who cares? Microsoft used to say that stencil support was one of those vestigial OpenGL CAD features. Now it is mainstream with 8 bits and *enhanced* functionality on $100 cards with full support copied almost verbatim into D3D. The state engine means that other vestigial functions don't burden the rest of the API, until one day the market decides they're mainstream.
As for render to texture, they spent ages trying to agree and couldn't. I guess that's the price you pay for freedom, and I'm talking about IHV freedom. Let's remember that the ARB didn't fumble the ball, NVIDIA and ATI primarily fumbled and I like to think that when those two can't agree then neither one should be forced to use the other's semantics which is what happens in D3D.
They're lowering the bar to a point where they can get something agreed upon. With hindsight this could have been done 18 months ago but hindsight is always 20/20.
That's hardly a case against OpenGL on the whole, but feel free to use D3D, nobody's stopping you...... err... except Microsoft if you're on any platform but Windows.
Winner technology wise?!! What are you talking about. Your argument would say that Windows 3.1 was the flat out winner technology wise, but that is obviously wrong. D3D may be the flat out winner volume wise for games exclusively on Windows, but let's not pretend that this has anything to do with technology. Microsoft has been pushing D3D as the Windows 3D API for years, that is why it is the most often used.
FWIW PS2 has no interface beyond a packet description and a DMA engine, it is popular because of the market, many programmers *hate* developing for the PS2, but PS2 has the biggest market share. If you jusge by volume then OpenGL will be the winner 'technology wise' in a year or two when Sony uses OpenGL|ES it on PS3 (a possibility) and OpenGL|ES becomes prevalent on mobile devices like cell phones (a certainty).
Slashdot Mirror
Your original post was incorrect, skydiving is not actually freefall, infact it is nothing like it. Although it is often called that, the force of air constantly acts on the participant. Other people correctly described why it is acceptable to call this zero-G and gave descriptions of why that have been generally accepted as a description of the phenomenon and you foolishly tried to correct them. Your subsequent posts attempted to correct physically accurate descriptions because they use commonly accepted terms for this like zero gravity (and micro gravity), are misguided. This is zero gravity in the frame of reference of the aircraft.
Yes, so is falling in an parabolic arc inside a plane deep in Earth's gravity well.
What you should realize is that when ISVs encounter the typical Mac mailbomb campaign and flamage they quickly learn that it is something they want to avoid. The irrational tirades of the loyal legions just plane scare developers away. Even developers who want to throw a bone to the Mac community find that it ain't worth the hastle feeding a beast that seems to think it's entitled to take your hand off. The ISV I used to work for was subjected to this kind of insanity because a pundit suggested a port was in the offing, we were immediately mailbombed by legions of rabbid crazy people that put Slashdot Anonymous Coward posts to shame. Even the more legible posts were profoundly foolish suggesting business justifications and citing the "huge mac installed base" with not a single fact to back up vague assertions. Folks in the office just laughed at this tripe, in short the Mac community made a horses ass of itself. Your hatred of Real as one of the ISVs that does support your platform just illustrates that same attitude. Unfortunately it's just much better for ISVs to ignore the Mac and avoid the flamage.
You have a profoundly flawed understanding of physics. The only difference falling in a plane and falling in an orbiting spacecraft is the air friction. The orbiting spacecraft misses the Earth thanks to it's velocity. The aircraft in this case counterracts the forces on air friction *nothing else*. So you're as weightless as you would be in space, and in fact it is *exactly* like an orbit in a physical sense when you're inside the plane.
They are different experiences, when you skydive you never feel weightlessness, you exit the aircraft and the rush of air from your forward motion exerts a lot of acceleration force (deceleration) on you then this eventually becomes the force of air pushing you up against gravity as you eventually fall faster and more vertically at your terminal velocity.
Even jumping from a stationary platform like a balloon you only feel weightless for a few seconds as your velocity builds up.
People do get sick skydiving, but it is usually on the aircraft that it affects them the most, so it is probably fair to call this common air sickness. It is an interesting fact that the terminal velocity of vomit is less than the terminal velocity of a skydiver, so if you are sick in the air it 'falls up' relative to your position. Experienced Tandem skydivers have all learned this the hard way with queezy customers.
This is very different from skydiving and very similar to orbital flight. With typical skydiving you never actually feel a lack of acceleration force. The point is the box in this case has control surfaces and flies a parabolic arc to counter the forces of air friction, all forces of air friction are removed, and in the frame of reference inside the aircraft gravitational forces don't manifest as a perceived phenomenon. What do you think an Orbit is? It's a vehicle falling under gravity and missing the Earth because of it's velocity vector (in the Newtonian model), the two differences between this and an orbital flight are the control surfaces (and engines) on the vehicle eliminating the forces of air and the fact that the arc of motion intersects the Earth. If you call orbital flights zero-G then you should call this flight zero-G because the relevant difference air friction is eliminated with by the aircraft.
Skydiving when you exit the plane you immediately feel the force of air blasting you from the direction of flight, the speed of the aircraft is enough that this force is some significant portion of 1G, it actually feels like you're falling sideways once you're used to skydiving, skydivers call this "the hill". Eventually as you fall the forward motion is eliminated as you accelerate downwards but again it just feels like the vector from which the air is pushing you has changed. From then on you're lying on a cushion of air with a full 1G of gravity, and you feel this. Skydivers do seek the thrill of weightlessness by jumping from relatively stationary platforms, like Helicopters or Hot Air Balloons, unlike normal skydiving from an moving plane you get that lump in your throat "I'm falling" feeling for a few seconds at the start of the jump. Same with BASE jumping.
It's also worth noting that receivers have a **DISH**, this basically makes required power levels for decent reception considerably less. You're not sticking rabbits ears, you're collecting a signal over the area of the surface of the dish and reflecting & focusing it towards the receiver. Moreover the satellite has a dish too that basically does the opposite with the transmitter, meaning that almost all its transmission power is directed Earthward, not randomly transmitted unlike a typical terrestrial station. So we're not really comparing apples with apples here.
Yea and the da Vinci launch should be much more fun to watch seeing as it's more likely to blow up.
Proofs cannot be contradicted that's the point. That's why it's called a proof.
Just so you get a chance to see this reply, that .plan ref was an example not a claim as to what you were referring to, that should have been clear from my later mention of a citation. Now that I've seen the quakecon video I can see he was complaining about the pixel buffers for next generation game. ONE feature and a legacy one, mainly for performance issues w.r.t. the context switch and a feature that OpenGL has had since before D3D existed. *everyone* knows this is an issue including me, if you'd read the other threads or opengl.org you'll see it discussed at length. He was expressing frustration at the intransigence of the ATI & NVIDIA engineers not compromising on the spec, not saying he would seriously go D3D. This extension has been knocked around for ages by ATI & NVIDIA and since they can't agree they're now going to push out a less ambitious render to texture spec. In other words, move along there's nothing to see.
FWIW I never said it was the original .plan just raise that as an example. Now that I've seen the quakecon video he was complaining about the pixel buffers for next generation game. ONE feature and a legacy one, mainly for performance issues w.r.t. the context switch and a feature that OpenGL has had since before D3D existed. *everyone* knows this is an issue including me, if you'd read the other threads or opengl.org you'll see it discussed at length. He was expressing frustration at the intransigence of the ATI & NVIDIA engineers not compromising on the spec, not saying he would seriously go D3D. This extension has been knocked around for ages by ATI & NVIDIA and since they can't agree they're now going to push out a less ambitious render to texture spec. In other words, move along there's nothing to see.
Oh I've let it go, it was never an issue for me, just an observation.
Ahh.... so something you don't agree with or can't see equates to rampant speculation reguardless of the foundation. Your POV does not make my post speculation.
If it had been cited I might have checked it out, as for the fanboy comment, sigh, grow up.
Fair enough, you never cited a source until now. I'll check it out. My choice to cite the original .plan was implying that was what you intended.
Sorry to break the news but Microsoft resigned from the OpenGL ARB effective February 15th 2003.
I already know this but it's off the table now. They have postponed the uber buffers extensions and are going for a simpler render to texture extension, they could not reach agreement. Yes you can use pbuffers but they are going for a cleaner (possibly more powerful) extension.
This has gotta be moderator abuse. TROLL? WTF?
How is this troll, *both* statements are 100% true, Lucas fired the original editor as mentioned in the film and Star Wars *DID* win an oscar for Best Film Editing in 1997, who the heck is moderating this?
What ignorant moron modded this as flamebait. If you don't understand the discussion then stay the heck away from moderating posts. Geeze!
You seem to be very confused. XBOX is basically a GeForce3 system with some extra vertex processors, yes it supports D3D but your assumptions about APIs are wrong. NVIDIA actually extended D3D on the XBOX with a few OpenGL like features that don't even exist today on Windows versions of D3D. So rather than D3D giving hardware the advantage it holds developers back, in a situation where hardware developers are free to extend (as they can with OpenGL) they do and bring innovative hardware features to developers early. In the unique case of the XBOX NVIDIA actually threw in a few extra functions they'd always wanted to expose on Windows D3D but couldn't because D3D didn't let them. With the shackles off on XBOX they did.
The only reason D3D is the API on XBOX is a Microsoft business decision, technical merits have nothing to do with it.
Learn DX or D3D? You do know that D3D is discontinued and Avalon is the replacement so what will it look like? I personally suspect they'll clean up D3D and it may wind up looking a lot different. The graphics scheduling, and resource/context management will obviously be a major issue/headache.
As for OpenGL, OpenGL|ES will have way more volume than longhorn units shipped, it will be on every mobile device. So I could justifiably claim that if you don't learn OpenGL|ES now you will be left behind, but I'd never say anything so silly.
Cross platform compatability is often a major goal but it depends on your project and what you're developing. Let's be clear, the hardware details and graphics programming requirements tend not to change from platform to platform, so OpenGL suitability is not compromised by it's cross platform support, it just happens to be supported on many platforms. Hardware acceleration and consistent implementation are the primary design goals of OpenGL and it succeeds spectacularly well. Implying that because it is cross platform it is somehow compromised ignores the fact that the only reason D3D is single platform (or even exists for that matter) is Microsoft's proprietary control of the market.
It's true that uber-buffers as proposed would be very general and very flexible, this is the holdup, but there's a strong case for not holding up needed features when your spec doesn't match current implementations, that's the heart of the problem.
Heh, spoken like someone who has never written a line of graphics code in their life. If you read Carmack's original OpenGL .plan you'll see that he was talking about how much cleaner OpenGL was to call.
You don't cite a reference w.r.t OpenGL & Carmack, it is clearly FUD. The only dissatisfaction I've seen from Carmack was in the Cg vs glslang hardware abstraction, I won't explain it, it's too technical for you but basically Carmack was advocating the futureproof open aproach and in some respects he got his way, however Doom3 calls ARBfp and ARBvp shaders anyway.
Carmack has never waivered from his OpenGL support and the only issue he's taken a public stand on in the API was as I said, shaders where he expressed a dislike for Cg and Cg is very similar to HLSL in D3D so Carmack was taking a stand against a shader approach that is used in D3D.
OpenGL has been around longer than D3D, is a lot cleaner in design, it has a clear unambiguius specification and has conformance tests to ensure quality of implementation. OpenGL is also portable to non-Windows platforms. All of these are excellent reasons to use OpenGl that have nothing to do with being non-Microsoft.
Your final sentence describes OpenGL better than it does D3D or are you in the habit of making random function calls to enable state you are not interested in using? There are vestigal parts of OpenGL, but they pose little implementation burden and are accelerated on high end cards where major CAD and DCC applications support them, really who cares? Microsoft used to say that stencil support was one of those vestigial OpenGL CAD features. Now it is mainstream with 8 bits and *enhanced* functionality on $100 cards with full support copied almost verbatim into D3D. The state engine means that other vestigial functions don't burden the rest of the API, until one day the market decides they're mainstream.
As for render to texture, they spent ages trying to agree and couldn't. I guess that's the price you pay for freedom, and I'm talking about IHV freedom. Let's remember that the ARB didn't fumble the ball, NVIDIA and ATI primarily fumbled and I like to think that when those two can't agree then neither one should be forced to use the other's semantics which is what happens in D3D.
They're lowering the bar to a point where they can get something agreed upon. With hindsight this could have been done 18 months ago but hindsight is always 20/20.
That's hardly a case against OpenGL on the whole, but feel free to use D3D, nobody's stopping you...... err... except Microsoft if you're on any platform but Windows.
Winner technology wise?!! What are you talking about. Your argument would say that Windows 3.1 was the flat out winner technology wise, but that is obviously wrong. D3D may be the flat out winner volume wise for games exclusively on Windows, but let's not pretend that this has anything to do with technology. Microsoft has been pushing D3D as the Windows 3D API for years, that is why it is the most often used.
FWIW PS2 has no interface beyond a packet description and a DMA engine, it is popular because of the market, many programmers *hate* developing for the PS2, but PS2 has the biggest market share. If you jusge by volume then OpenGL will be the winner 'technology wise' in a year or two when Sony uses OpenGL|ES it on PS3 (a possibility) and OpenGL|ES becomes prevalent on mobile devices like cell phones (a certainty).