More GVB questions

[Ieldra]

...perhaps someone can help me with this:

(1) Armor has no volume? That can't be right.... or if it is right, then why?

(2) My vehicle has a Payload stat. Where does it come from, and how can I influence it?

(3) When I set performance profiles, there's a "payload" parameter. When I increase it, my vehicle gets faster. That can't be right.... or perhaps this parameter is used for something else. Can anyone explain?

(4) How do I convert power to energy? It seems my laser can't use the power generated by the fusion reactor directly? Why not? In one of the example ships, I've seen this.

[tjoneslo]

I, the Vehicle Guru will answer your questions:

1) Correct, Vehicle (and GVB) assume armor has no volume, as an abstraction to ease construction. Vehicle Expansions 2 (and GVB) has an option to make armor take volume if you really can't stand the abstraction.

2) Payload weight includes things like weight of crew and passengers, ammunition, fuel, and cargo.

3) The basic performance formulas use vehicle total weight. Some people wanted the option of removing some of the payload (like half of the fuel, or the all of the ammunition). By increasing the "payload" parameter of the performance profile, you are decreasing the total weight of the vehicle, thus improving performance. The idea is you can link the payload item (like the ammunition or fuel) directly to the performance profile so it updates properly.

4) You should be able to create the links. If you can explan more about what you are trying to do, I can write you an example of how to do it.

[Ieldra]

Originally Posted by tjoneslo

You should be able to create the links. If you can explan more about what you are trying to do, I can write you an example of how to do it.

Well, it's easy...or it should be. I want to put a laser into my vehicle that draws its energy directly from the power plant, not from energy banks. I could always use one of the custom weapon types, but they're not as easily configurable as the ones in the regular weapon repository. What it comes down to, I'd like the weapon to be like, for instance, the "TL8 laser", where I can set range, power, shots etc.., and have GVB calculate the rest for me, with the only difference that it draws on the vehicle's power plant directly.

And BTW, thanks for the other answers.

[tjoneslo]

I'm still not clear on what you mean by "link". The term has a specifc meaning within GVB and can cause confusion on my part. So I'll make some assumptions about it, give an explination, and you can point out where I've gone wrong.

I'll assume your vehicle has a fusion power plant and a laser componet added from the repositories, and they are in the same package or component (like the body).

There are two way to link these component together. First is: I want the laser to always use 10% of the power of the fusion plant. The second is: The fusion plant is dedicated to powering the laser, so whatever output I need for the laser, make the fusion plant the proper size.

First way: Right click the package and select "New link node..." from the context menu. In the Edit component links dialog, select (in the select lists from left to right), laser component, rating property, enter 0.1 in the text box, then the fusion plant component and the Total Power Out property. Press OK. Now as you increase or decrease the power of the fusion plant, so does the laser power. You will need to set the remaining items for the laser to get the type you want. You will also need to pay attention to the Kj (output) and the kWs (or kj input) ratio and adjust your multipler in the link above.

Second way: Create the new link as above, and in the edit component dialog select fusion power plant component, rating property, enter 1 in the text box, then select laser component and Total energy In property.

If it's not apparent from the description above, the beam weapons still use the qantity and rating items that the other templates use, they are just not labled on the edit dialog. Quantity is quantity and ratiing is the Kj input.

Does that answer your question or have I missed it entirely?

[Ieldra]

I never mentioned the term "link" - not in any of my posts. Apart from that, I didn't want to make a quantitative link from the power source to the power-using item.

To make it all very clear: I have a small spaceship with two turrets. I want to add a "TL8 laser" from the beam weapons repository to every turret, and I'd like the lasers to be powered by the ship's main power plant.
The problem: after I add the lasers, "Energy in" shows up in their display, but they don't draw on any power *at all*.

As an example, if my power plant has 10 MW and my lasers have an energy output of 200KJ each and an RoF of 2, making for a total power requirement of 800 KJ/s = 800 KW, the power plant should be able to supply the power for the lasers. But that isn't what happens. Instead, I get a energy need I haven't supplied and a power output I don't need.

Further analyzing this problem, I see that the calculation above makes the assumption that a laser shot from a laser with RoF 2 takes 0.5 seconds, which is, IIRC, the correct interpretation of what I read in GURPS Vehicles, that a laser shot is a continuous beam unless stated otherwise.

To avoid using assumptions like this, for instance, in order to create a pulse laser, I could use energy banks, which I understand is the default way to power lasers in GURPS Vehicles. But apart from the fact that I don't always want to do this, the result is an incorrect power balance, since the energy banks must be recharged, and they don't have a power-in parameter.

All this means that, whatever I do, the power balance is wrong, and maybe the energy balance, too. For this small spaceship, it's not a big problem. I can do the calculations myself and be done with it. But with Star Wars-Type spaceships I'd need an extra spreadsheet for the power and energy calculations, and I always assumed GVB existed to take care of these things for me...

EDIT:
Maybe the best way to handle this is to duplicate the power cell template and edit the new template to be rechargeable in one second (Power In = Energy Out / 1 s). After I have added the power cells to power the lasers, I'll have a meaningful power balance again. This is an around-the-corner simulation of a weapon powered by the power plant, but it does the job, and maybe it's even technically somewhat realistic.

EDIT2:
Ticking the "rechargeable" checkbox should add a power need to power cells and suchlike, as a fraction of the energy output, to show the maximum recharge rate, maybe TL-dependent. This should also be editable up to the energy output.

[tjoneslo]

Ah, the light dawns, the problem being (for example) the Total Power Use + Total Energy Used should match the Total Power produced + Total Energy Produced on the Edit Body (or other subassembly) dialog.

Unfortuantely, from the persective of GVB, power and energy are two completely different things in the way that cost and weight are different.

The only way to do this is to build a power converter component, in the manner you suggested, by copying the powercell component and making sure there is both a power in and energy out.

There is no requirement in GVB that the energy and power requirements match, which is probably why no one else has complained of this.

If you ever get the "power converter" component working properly, post a copy of the component output here on the forumn so I can add it to the GVB base repository.