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[1.5 - 1.12.5] BetterSRBs [v1.2.6] [30 June 2021]


OhioBob

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45 minutes ago, linuxgurugamer said:

First, could you add NovaPunch support?  I'm reviving it, as of now, I'm pretty sure nothing will be changing in the SRBs.

That shouldn't be a problem, I'll take a look at it.  (I still need to also look at USI Sounding Rockets.)
 

Quote

Second, could we get this added to CKAN?

I don't use CKAN myself, so I have no idea what's involved in getting added to it.  That's something I suppose I should figure out.
 

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1 hour ago, OhioBob said:

That shouldn't be a problem, I'll take a look at it.  (I still need to also look at USI Sounding Rockets.)
 

I don't use CKAN myself, so I have no idea what's involved in getting added to it.  That's something I suppose I should figure out.
 

I can do the CKAN for you, if you want

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42 minutes ago, linuxgurugamer said:

I can do the CKAN for you, if you want

OK, I'll talk to you about it before my next release.  That won't be before KSP 1.5.1 at the earliest, however.

I think I've got all the math worked out for the NovaPunch SRBs.  I now just have to write up the cfg.  After I'm finished, I'd like you to look it over to make sure I haven't missed something.

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@Oneiros, I've looked at the USI Sounding Rockets mod and I've decided not to include any changes to it in BetterSRBs.  That mods includes a entire group of parts that are designed and balanced to work together in a specific way.  Changing the specs would mess up what the mod author intended.

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  • 2 weeks later...
6 hours ago, vardicd said:

Would it be possible to include configs for the SRB's added/modified by this mod to your own, @OhioBob?

That looks like something that I shouldn't mess with.  All those parts are designed to work together in a specific configuration.  Changing the specs would throw the balance out of whack to where it no longer performs as intended.

Generally speaking, if a part pack looks like the author intends the parts to be assembled in a specific way, I'm assuming those parts have been balanced to achieve a certain level of performance was so assembled.  Therefore, I have no plans to include these part packs in BetterSRBs because doing so would upset the internal balance of the part pack.  On the other hand, if a part pack simply provides an assemblage of SRBs of various sizes for the player to do with as he so pleases with no clear intention of how those parts are to be put together, then that part pack is a candidate to be included in BetterSRBs.
 

Edited by OhioBob
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12 hours ago, OhioBob said:

That looks like something that I shouldn't mess with.  All those parts are designed to work together in a specific configuration.  Changing the specs would throw the balance out of whack to where it no longer performs as intended.

Generally speaking, if a part pack looks like the author intends the parts to be assembled in a specific way, I'm assuming those parts have been balanced to achieve a certain level of performance was so assembled.  Therefore, I have no plans to include these part packs in BetterSRBs because doing so would upset the internal balance of the part pack.  On the other hand, if a part pack simply provides an assemblage of SRBs of various sizes for the player to do with as he so pleases with no clear intention of how those parts are to be put together, then that part pack is a candidate to be included in BetterSRBs.
 

I completely understand. I may have to poke around in your SRB configs to see if I can figure out how to adjust the SRB configs from the mod myself. I'm only using the SRB's from the mod, because some of them have gimbaling, which is nice. Since I'm not using the whole mod pack, I'm not personally concerned with the internal balance of the mod, but that's just me.

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2 minutes ago, vardicd said:

I completely understand. I may have to poke around in your SRB configs to see if I can figure out how to adjust the SRB configs from the mod myself. I'm only using the SRB's from the mod, because some of them have gimbaling, which is nice. Since I'm not using the whole mod pack, I'm not personally concerned with the internal balance of the mod, but that's just me.

It should be easy to write your own cfg.  I can probably help if you run into a roadblock.

By the way, BetterSRBs adds gimballing to the Thumper and Kickback.  The added SRBs also have gimballing.

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1 hour ago, OhioBob said:

It should be easy to write your own cfg.  I can probably help if you run into a roadblock.

By the way, BetterSRBs adds gimballing to the Thumper and Kickback.  The added SRBs also have gimballing.

Really? I missed that. Cool to know.

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9 hours ago, OhioBob said:

It should be easy to write your own cfg.  I can probably help if you run into a roadblock.

So After looking at the configs in better SRB's I've reached an important realization. I have no idea what parts of the configs control the changes you've made to the SRB's. My skills are limited to being able to add a resource to a part, or add a consumer/producer to a part. Such as a custom power generator I made for myself, but I've never tried to create/modify an engines thrust before, and I don't understand what the thrust curve is suppose to represent, or how it's supposed to be read, same for the atmosphere curve, and how those interact with an engine's max thrust, and specific impulse [if that's important?] If there is any sort of guide, or information you could point me towards to help me understand these things, or if you find yourself with some free time and can explain these for me yourself, I'd be really grateful. Please bear in mind, I know you're probably a busy person, and I don't want you to inconvenience yourself for one person's crazy quest to mod some extra parts. thank you for your time.

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1 hour ago, vardicd said:

So After looking at the configs in better SRB's I've reached an important realization. I have no idea what parts of the configs control the changes you've made to the SRB's. My skills are limited to being able to add a resource to a part, or add a consumer/producer to a part. Such as a custom power generator I made for myself, but I've never tried to create/modify an engines thrust before, and I don't understand what the thrust curve is suppose to represent, or how it's supposed to be read, same for the atmosphere curve, and how those interact with an engine's max thrust, and specific impulse [if that's important?] If there is any sort of guide, or information you could point me towards to help me understand these things, or if you find yourself with some free time and can explain these for me yourself, I'd be really grateful. Please bear in mind, I know you're probably a busy person, and I don't want you to inconvenience yourself for one person's crazy quest to mod some extra parts. thank you for your time.

A thrust curve is not necessary but it's a nice feature.  What it does is generate a thrust multiplier as a function of fuel fraction remaining.  That is, Thrust = maxThrust * thrustCurve.  Without a thrust curve, an SRBs will generate constant thrust throughout its burn (not counting, of course, changes in thrust due to changing ambient air pressure).  I use the same thrust curve for all SRBs:

		thrustCurve
		{
			key = 0 0.1 0 33
			key = 0.04 0.76 0.79 0.79
			key = 0.54 1.155 0.79 0.79
			key = 0.65 1.1785 -0.51 -0.51
			key = 1 1 -0.51 -0.51
		}

The first number in each key in the fuel fraction, and the second number is the thrust multiplier.  So in the curve above you can see that when the SRBs has a full fuel load (1), the thrust multiplier is 1.  Therefore the thrust at ignition equals maxThurst.  When 65% of the fuel remains (0.65), the thrust has increased to 1.1785 times maxThurst.  And so on.  I'm sure you can use the same curve for what you want to do, I see no reason to modify it.

atmosphereCurve gives the specific impulse as a function of atmospheric pressure.  The first number is the air pressure in atmospheres, and the second number is the Isp.  For instance,

		atmosphereCurve
		{
			key = 0 265
			key = 1 240
			key = 10.6 0.001
		}

When the pressure is 0, the Isp is 265 s; and when the pressure is 1 atm, the Isp is 240 s.

 

 

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6 hours ago, OhioBob said:

A thrust curve is not necessary but it's a nice feature.  What it does is generate a thrust multiplier as a function of fuel fraction remaining.  That is, Thrust = maxThrust * thrustCurve.  Without a thrust curve, an SRBs will generate constant thrust throughout its burn (not counting, of course, changes in thrust due to changing ambient air pressure).  I use the same thrust curve for all SRBs:


		thrustCurve
		{
			key = 0 0.1 0 33
			key = 0.04 0.76 0.79 0.79
			key = 0.54 1.155 0.79 0.79
			key = 0.65 1.1785 -0.51 -0.51
			key = 1 1 -0.51 -0.51
		}

The first number in each key in the fuel fraction, and the second number is the thrust multiplier.  So in the curve above you can see that when the SRBs has a full fuel load (1), the thrust multiplier is 1.  Therefore the thrust at ignition equals maxThurst.  When 65% of the fuel remains (0.65), the thrust has increased to 1.1785 times maxThurst.  And so on.  I'm sure you can use the same curve for what you want to do, I see no reason to modify it.

atmosphereCurve gives the specific impulse as a function of atmospheric pressure.  The first number is the air pressure in atmospheres, and the second number is the Isp.  For instance,


		atmosphereCurve
		{
			key = 0 265
			key = 1 240
			key = 10.6 0.001
		}

When the pressure is 0, the Isp is 265 s; and when the pressure is 1 atm, the Isp is 240 s.

 

 

Okay, that makes sense, and is easy enough to understand, I was trying to read the thrust curve from the top down, and it wasn't making sense to me, but as soon as you explained it and I saw it was meant to be read bottom up I can see the numbers and fractions. question though, on the atmosphere curve, what does the third line mean? "Key = 10.6 0.001?" and the top line of the thrust curve,  "Key = 0 0.1 0 33" Is there a reason that isn't "Key 0 0.1 0 .33" since the lower lines are noted as 0.76? Also what are the third and fourth numbers in each line of the thrust curve?

Edited by vardicd
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25 minutes ago, vardicd said:

Okay, that makes sense, and is easy enough to understand, I was trying to read the thrust curve from the top down, and it wasn't making sense to me, but as soon as you explained it and I saw it was meant to be read bottom up I can see the numbers and fractions. question though, on the atmosphere curve, what does the third line mean? "Key = 10.6 0.001?" and the top line of the thrust curve,  "Key = 0 0.1 0 33" Is there a reason that isn't "Key 0 0.1 0 .33" since the lower lines are noted as 0.76? Also what are the third and fourth numbers in each line of the thrust curve?

The last line on atmosphereCurve is where the thrust goes to zero.  Specific impulse is a straight line function that goes through the points (0, 265), (1, 240) and (10.6, 0).

The 3rd and 4th numbers in each key of the thrustCurve are the slopes of the curve.  They are the slope in and the slope out at that particular point.  The first key (which is really the end of the burn) is where the thrust is rapidly decaying, so the curve has a steep slope at that point.  You can see this if you look at the curve in the OP.

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7 hours ago, OhioBob said:

@vardicd, I just took a look at the SRB configs for reDIRECT.  It's already using thrust curves and realistic Isp.  I see no need to change anything, it looks fine as is.  

Oh.... I hadn't actually had time to sit and sort through the configs for it yet... Well, at least I have some idea of what I need to do in the future, should I need to change SRB's.

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6 hours ago, vardicd said:

@OhioBob Question for you, there are 4 SRB's included in the RLA Reborn mod being maintained by Linuxgurugamer 3 .625m SRB's {boostertron I, II, and III and the SMAC Payload assist motor} would these be candidates Better SRB's?

Yes, that looks like something I should add.  The mod does a good job of filling in some gaps in the stock parts.

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