Vega Strike Forums

Oh - now I notice. I posted the links in the wrong thread - go to the Hornet's thread, you'll find something there.

I think we were posting at the same time and you missed my post, klauss.
That paper is IT...
If we can add that to paralax, it will be the ultimate shader: Paralax + outline clipping without stencils (outer as well as inner outlines). Should only take a few GPU instructions to do it, and a modified normal mapper app. Please don't dismiss the paper because of the use of a 3D texture; like I said, I think this should work with just one more parameter per texel, for cone size.

chuck_starchaser wrote:I downloaded NFZ's normal mapper; comes with sources; shouldn't take too long to have it add cone size to the alpha channel or something.

While you're at it, could you also make it run under linux? I wouldn't mind if the blender-plugin called WINE.

I'm reading this, and the words all make sense, but if you put them all together it's big woosh over my head.

On the plus side, does anyone want an UAV? I built one but don't have the money to patent it.

Unmanned Aerial Vehicle? What would be the subject of the patent? Does it use a novel idea? You sound like a mad scientist; we should start a club.

Just got myself the cvs-version of Blender and it's very impressive.
The sculpt-tool is simply amazing. I can't stop playing with it. Finally got tangent-space-normalmaps working and on top of that rendertimes have dropped considerably.

As a consequence of the sculpt-tool and Reyes integration it's very likely that Blender will be able to generate displacement- and normalmaps in the short future. Now wouldn't that be nice.

Btw the coder of the sculpt tool coded another amazing tool, it's called retopo. It works like this.
You set an object as a target, when you now create a new object the vertices will snap to your target.
This enables you to trace over a model with bad topology or too many polys. Example


Whoohoo!
Now that is one usefull tool.
You don't even have to think about polycounts anymore while modelling. Just trace over when you're done and make some LOD's while you're at it.

Allright, how's this?



I'll criticise it first:
1) Unequal cannons. I don't like it, yet can't get out of it easily.
2) They don't look like lasers; --and I don't mean lab lasers, or the new Jumbo Jet mounted laser; I mean they don't look even like scifi lasers, but then again I'm not sure what scifi lasers look like.

3) No mechanics for recoil. If you want a recoil that is.

Can't really help you on the laser-canon front. I'm only familiar with howitzers and the like.

The gun in the middle looks just like a cartoon-gun. You know the one that ends up in curled up shreds when fired.

Another suggestion, make the slots in the dome so small that the barrels can just fit through and hide the mounting from view. Maybe you can get away with not modelling the guns intenals and mounting at all. Leave something to the imagination of the viewer/player.

DualJoe wrote:3) No mechanics for recoil. If you want a recoil that is.

LOL, I was about to edit my post to say just that. Well, no details whatsoever yet, since I'm not sure the overall shape is a go or not.

The gun in the middle looks just like a cartoon-gun. You know the one that ends up in curled up shreds when fired.

Well, the stupid flare at the front is only there to match the WC3 pic you posted where they are looking at the guns through big windows. I don't like it myself; makes not an iota of sense. But then again, nothing does. I suppose it would look less cartoonish with some greebles around the thinner part of the cylinder. Being supposedly a "laser" (though I doubt the Origin people would know a laser from a hole in the ground) I suppose there'd be some gas circulating pipes and whatnot.

EDIT:
By the way: If a laser experiences recoil, what part of it does, exactly? I mean, in a particle canon I suppose it would be the coils that experience a reaction force, but in a laser ...
Then again, I think I heard the argument that what Origin calls "lasers" are actually plasma cannons, which must be like some kind of highly focused solar flare producers. I suppose plasma cannons would have 4 main coils, though I've never seen coils in any of the WC artwork...

chuck_starchaser wrote:though I doubt the Origin people would know a laser from a hole in the ground

Haha, you could be right there. Another reason could be that the quasi 3d sprite engine they had at the time wouldn't show those details anyway, so why waste time and money on it.

chuck_starchaser wrote:I suppose plasma cannons would have 4 main coils, though I've never seen coils in any of the WC artwork...

Look at it this way: As long as there's no artwork showing the contrary you're free to do as you please.

Alright; I've never seen recoils; is this what they look like?



There's something I still don't like about the whole thing; not sure what it is.

chuck_starchaser wrote:By the way: If a laser experiences recoil, what part of it does, exactly? I mean, in a particle canon I suppose it would be the coils that experience a reaction force, but in a laser ...

The back mirror. A simple laser construction is done by photons propagating back and forth between two mirrors. One is only partially reflective, so photon can leave through it. The effective netforce comes from photons that reflect on the back mirror and then leave the resonator.

Try making the guns smaller again at the tip.

Yeah, that looks better...



I should have guessed... But do lasers *really* produce recoil? Say, the big laser the US has on that modified 747, does it, or should it, experience a significant recoil?

I had a big explanation of why lasers would feel recoil, and where (the laser cavity), but it got deleted on a "DNS failure" so I won't type it again (if you really really really want it, mail me).

In short: I'd support the steamy coolant option. You'll need recoil mechanisms if you intend to mount a plasma cannon, but for a laser cannon, I'd say you should greeble coolant-ish stuff. Like heat sinks, vents and the like.

Damn. Sorry to hear that; I hate to lose stuff. Yeah, that's what I would have thought. I think I'm gonna go with plasma and recoil, though, as really, there are no lasers at all in WC. I mean, the bolts we see aren't travelling at the speed of light, obviously, and if they were lasers we wouldn't see them in the first place. So, I think plasma guns they are.

klauss wrote:I had a big explanation of why lasers would feel recoil, and where (the laser cavity), but it got deleted on a "DNS failure" so I won't type it again (if you really really really want it, mail me).

In short: I'd support the steamy coolant option. You'll need recoil mechanisms if you intend to mount a plasma cannon, but for a laser cannon, I'd say you should greeble coolant-ish stuff. Like heat sinks, vents and the like.

Let me try in not so many words. The reason why a laser would have recoil is the same reason why a Solar Sails and a Photon Drive would work. Even though a photon has no mass it can exert presser, hence recoil. The good news is the the recoil should be very mild, the the amount of presser is more dependent on the intensity of the light being projected.

Thanks. That's what I thought. I'm no physicist, but I think I've read that a photon, although it has no mass, it has momentum; but that the momentum is a constant. Now, I may be wrong, but I seem to remember that the momentum of a photon is a constant constant, --independent of the wavelength, I mean; like a universal constant for all photons. So, the recoil would depend on the number of photons we shoot, rather than on the total energy of the shot. With shorter wavelenth photons, like ultraviolet or X-ray, we'd do more damage without increasing recoil.

This is going more in the direction of plasma, though. The pipes conduct liquid coolant for the main coil, as well as the conductors. The choke coils would be in the narrow sections and I can do them with the normal map. The thin coil at the business end is an exhaust shaping coil. Very preliminary; more stuff to come.



The boxes at the back, the pipes slide into them during recoil. How they help I don't know; that's magic; thing is, I didn't know what else to do without going over the top with poly count. In any case, who's ever even going to look at this thing close enough while it's firing to notice the recoil animation, never mind wondering how the pipes might flex inside the boxes?

chuck_starchaser wrote:but I think I've read that a photon, although it has no mass, it has momentum; but that the momentum is a constant.

Almost a photon has no mass (actually, a thought just popped into my head that suggests that this isn't quite true ... but I could of course also just be going crazy), but certainly has a momentum that depends on it's frequency p = h.f/c I think. So the higher the frequency, the higher the momentum per photon.

XRay laser's are interesting, mainly because of the material properties they would require, but if ever made would have higher 'recoil' than higher wavelengths.

Dan

Thanks, I stand happily corrected.

dandandaman wrote:(actually, a thought just popped into my head that suggests that this isn't quite true ... but I could of course also just be going crazy),

Stands to reason, actually. Momentum over velocity. If p = h.f/c then m = h.f/c^2. Do the units make sense for mass? Anyhow, the rest mass may be infinitesimal, but photons don't exist at rest, so the standard argument is neither here nor there.

Just minor fixes, for now,



Doh! Just because it's plasma, doesn't mean the shot shouldn't travel almost at the speed of light, does it? Oh well, to hell with it. I doubt many people will criticize the Bengal for the pseudoscience...
But just curious, what should an X-ray laser look like?

I think current x-ray lasers use undulators ( http://en.wikipedia.org/wiki/Undulator ).

About the photon mass: chuck, you realize that the p=v*m equation is only valid for things with a nonvanishing rest mass and small (i.e., nonrelativistic) velocities? A photon's rest mass is zero, that's why they can/must travel at the speed of light as opposed to any other particle with a rest mass.

The cannon is looking good. Those greebles make it look really powerfull!

I'm concerned with the cannon tips - during recoil, wouldn't they hit the pipes?

I'm thinking that during recoil, only the cannon itself (the inner coils) move back, leaving the outer pipes stationary. That would a) look good, b) be somewhat realistic, c) cannons actually recoil like that at present, so it's "natural looking".

I wouldn't mind a comparison shot of your "rest" position and your "wound up" position, to get an idea of what you're thinking.

Otherwise - cool. Check the polycount, though. Remember, they're turrets. If you make them with too high a polycount, we'll need LODs

Thanks! Yeah, I just need to add the hydrogen injection pipes, like for feeding the plasma, and a wire for the microwave antenna inside, that turns the hydrogen into plasma in the first place. I might put them under the guns, and let them be visible when the gun points a bit upwards; not sure. Just a bit worried too; I'm already at 5352 facets total, which is problably around 8000 tris. And I was thinking, "okay, this is just one of a kind", but actually, the gun on the bottom side tower is supposed to be heavy also. Then there's 8 medium heavy guns on the wing hanging boxes, which I thought were going to be dual versions of this gun (middle one removed; the other two squeezed), but I may have to do something drastic to simplify this thing.

About the photon mass: chuck, you realize that the p=v*m equation is only valid for things with a nonvanishing rest mass and small (i.e., nonrelativistic) velocities? A photon's rest mass is zero, that's why they can/must travel at the speed of light as opposed to any other particle with a rest mass.

What I was saying was that the fact that the rest mass of the photon may be zero by calculation is irrelevant, since a photon is never at rest. But if you say p=v*m is only valid for rest-mass, I'll take your word for it.

Just thinking of an undulator laser design... Cylindrical chamber, vaccum, cylindrical rod in the middle with superconducting coil passing a constant DC feed, positively charged, if it helps. Electrons injected from the side get accelerated by syncrotron type plates outside the cylinder. Then a serpentinely shaped superconductor on the outside of the cylinder that goes back and forth along the full length as it completes a turn or more around, gets a sudden shot of current from a large capacitor, producing multiple, radial magnetic fields with opposite polarities. Instantly, all the energy stored on the spinning electrons in the chamber turns into syncrotron radiation along the axis. And best of all, it should be easy to model in Blender
Would that work?

EDIT:
@Klauss: We always post at the same time, don't we?
What I was thinking was the whole thing, with the pipes, and greebles, recoiling. My recoil piston is where the narrow section at the back meets at a sharp (split vertices) angle with a wider cylinder attached to the vertically rotating base. The only greebles NOT recoiling would be the boxes around the back cylinder. But having the greebles stationary could be arranged. Let me have a coffee and a smoke with that thought...

EDIT2:
Nah, can't be done. The pipes bend and enter the casing around the plasma chamber. There's six places so far, and there will be two more. I'd have to put flex pipe sections all over the place...

I'm sorry to take this a bit off-topic.

chuck_starchaser wrote:

About the photon mass: chuck, you realize that the p=v*m equation is only valid for things with a nonvanishing rest mass and small (i.e., nonrelativistic) velocities? A photon's rest mass is zero, that's why they can/must travel at the speed of light as opposed to any other particle with a rest mass.

What I was saying was that the fact that the rest mass of the photon may be zero by calculation is irrelevant, since a photon is never at rest. But if you say p=v*m is only valid for rest-mass, I'll take your word for it.

The point is, that the total energy of a freely moving particle (massiv or not) has two possible contributions. One from it's momentum and one from the fact that is has a rest mass.
The total energy is: E^2 = p^2 c^2 + m^2 c^4
which leads to the known formula for the photon energy only if m=0, and for slow particles to the kinetic energy plus energy due to the rest mass. The term "rest mass" is a property of a particle that exists even if the particle cannot be at rest. Overemphasizing, it's a particular property, not something you get when you put it on a scale and stand next to it in order to have no relative velocity. (Just think about how you would define 'being at rest' taking into account different reference frames and the uncertainty relation.)

Now, I'll shut up about it.

Okay, that makes sense. Didn't know the energy formula. Now, about the last bit, being at rest relative to a photon is impossible by definition, even if you were a photon; c being c relative to ANY frame of reference, --no exception made for frames of reference moving at c
We might all be moving at c and not know it
Just kidding; I know it's a meaningless statement.
Anyhow, let me take that formula: E^2 = p^2 c^2 + m^2 c^4
So, rest mass is 0; no problemo.
E^2 = p^2 c^2
E = pc

Now, let me be creative here
E = p/c . c^2
E = mm . c^2
mm = E / c^2
Where mm is "something", mass-like, though certainly NOT mass at rest.
Could it be the "mass at c"? Just wondering. Maybe it turns out that there's another fundamental property like "mass at rest", being "mass at c", which is irrelevant for entities with a non-zero rest mass, but which becomes relevant for entities with a zero rest mass.

Some writings tell you that a body's mass increases to infinity as its speed approaches c. Your mm is what is "added" to the rest mass due to kinetic energy.
The m in E=mc^2 is not the sole rest mass but a composition of it and your mm, so to speak.