Criticise this model (1st serious model)

[mariohm1311]

This is my first serious engine model. May I receive some constructive criticism?

As you can see, the turbopumps are modelled, as well as the Gas-generator loop; so it's a middle point between the Squad models, and the true to life ones. It is supposed to be a Size-1 engine with a thrust between the Skipper and the LVT-30. It will not be thrust vectoring capable, as you can use fins or 24-77s as Verniers. Tell me what you think.

- - - Updated - - -

From another point of view:

From here you can see the fuel pipe going to the fuel pump, and the oxidizer pipe going to the oxidizer pump.

Edited May 8, 2015 by mariohm1311

[mariohm1311]

Anyone?

[CaptainKipard]

OK. I can only see some flaws with it:

1. That vertical thing that's off to the side could use more faces radially if you know what I mean. I could be as detailed as those doughnuts on the top of it.

2. The exhast could use two more edge loops to smooth out the curvature of it.

3. You could try to keep the number of faces consistent for round objects like the exhaust and the ring around the bottom of it. For whatever reason it looks twice as detailed when it doesn't need to be.

[mariohm1311]

OK. I can only see some flaws with it:

1. That vertical thing that's off to the side could use more faces radially if you know what I mean. I could be as detailed as those doughnuts on the top of it.

2. The exhast could use two more edge loops to smooth out the curvature of it.

3. You could try to keep the number of faces consistent for round objects like the exhaust and the ring around the bottom of it. For whatever reason it looks twice as detailed when it doesn't need to be.

Thanks for your answer! You're always willing to help. So:

1. That sort of box?

2. Yeah. I'll probably do that with the first edge (the second one is behind the Gas-Generator loop). Regardless of that, it seemed good with the bevel modifiers and smooth faces.

3. Ok. Gotcha.

One extra question: I have checked other models, and faces are triangulated. What are the advantages of doing that?

[CaptainKipard]

1. That sort of box?

No the long vertical thing connected to the box and the exhaust.

One extra question: I have checked other models, and faces are triangulated. What are the advantages of doing that?

Quads get triangulated automatically, because 3D graphics work with triangles, but you should be modelling with quads because it makes for nicer edge flow. The only advantage to triangulating faces by yourself is in places where you need to specify how the edges flow. That's not something you need to worry about for now. When you get more practice, you'll probably come across a place where you'll need to do it. For now just work with quads.

[PB666]

OK. I can only see some flaws with it:

1. That vertical thing that's off to the side could use more faces radially if you know what I mean. I could be as detailed as those doughnuts on the top of it.

2. The exhast could use two more edge loops to smooth out the curvature of it.

3. You could try to keep the number of faces consistent for round objects like the exhaust and the ring around the bottom of it. For whatever reason it looks twice as detailed when it doesn't need to be.

The most efficient engines are SSME which does not show alot of detail at the base, basically a flat ring cylinder with the nozzle base feeding through .

They do however show alot of ribbing on the thruster body. The feul lines run back over the horizontal ribs.

https://en.wikipedia.org/wiki/Space_Shuttle_main_engine#/media/File:Pratt_Whitney_Rocketdyne_space_shuttle_main_engines.jpg

The top of this unit is shrouded on the vehicle. The shroud probably protects the turbocharger from the heat coming off the nozzle.

[CaptainKipard]

The most efficient engines are SSME which does not show alot of detail at the base, basically a flat ring cylinder with the nozzle base feeding through .

They do however show alot of ribbing on the thruster body. The feul lines run back over the horizontal ribs.

https://en.wikipedia.org/wiki/Space_Shuttle_main_engine#/media/File:Pratt_Whitney_Rocketdyne_space_shuttle_main_engines.jpg

The top of this unit is shrouded on the vehicle. The shroud probably protects the turbocharger from the heat coming off the nozzle.

I have no idea what you're trying to get across. It seems completely irrelevant to what OP asked about.

[mariohm1311]

No the long vertical thing connected to the box and the exhaust.

Ah, ok. That's the gas-generator loop and the doughnuts up there are the turbopumps driven by the gas created. Actually, those look pretty round with face smoothing and beveling. I made them so squary because I saw something like that in a KW Rocketry engine that low poly. Does it create problems when applying the texture (if I manage to UV unwrap it)?

[CaptainKipard]

Does it create problems when applying the texture (if I manage to UV unwrap it)?

No. but the smoothing shader might look a little off. I don't think 8 faces is enough for such a large component 12 seems more appropriate to me. You don't need to worry about triangle counts. If you make your models just detailed enough where increasing detail makes no visual difference, then it's ok.

Edited May 8, 2015 by Cpt. Kipard

[PB666]

I have no idea what you're trying to get across. It seems completely irrelevant to what OP asked about.

Seems that he was asking about an efficient design. The SSMEs are the most efficient with the highest ISP in the range (although it is somewhat larger).

https://en.wikipedia.org/wiki/Specific_impulse

So if you are not going after an efficient design, why create a thruster with r=0.625 size?

LV909 - ISP = 85 to 345

LV-T30 ISP = 280 to 300

LV-T45 ISp = 270 to 330

T-1 ISP = 290 to 340

Skipper = 280 to 320

Whats the point of having another Size1 Size2 rocket engine that performs in the same range. Its better to design one that operates between

These ranges and nuclear rocket range. IMHO.

[mariohm1311]

No. but the smoothing shader might look a little off. I don't think 8 faces is enough for such a large component 12 seems more appropriate to me. You don't need to worry about triangle counts. If you make your models just detailed enough where increasing detail makes no visual difference, then it's ok.

How can I add faces to something already there? And how can I make some sort of coupler between 8 faces and 12 faces? I'm sorry if I'm bothering you. I'm learning...

[PB666]

How can I add faces to something already there? And how can I make some sort of coupler between 8 faces and 12 faces? I'm sorry if I'm bothering you. I'm learning...

In blender its not easy

Add a 12 sided polygon(s) below your work piece and extrude regions upward and rescale inward over your 8 sided pieces matching radius as you move along. Then carefully delete your 8 sided pieces.

My experience with KSP is there is a preference for multiples of 6 except in guidance stuff (manuevering thrusters and winglets). Its always best to start with 12 or 24 sided objects.

Edited May 9, 2015 by PB666

[mariohm1311]

The nozzle itself is a 24 sided object, like the ones in KW Rocketry engines. I'll keep in mind that when I create something.

[CaptainKipard]

You can add new edge loops by using the loop cut tool (Ctrl+R), but if it's something that's meant to be round I'd just recreate the mesh the way PB666 said

[NathanKell]

Good start!

Don't be scared of polies, KSP is anything but GPU-limited, and a few thousand (heck, a few dozen thousand) faces isn't a problem, as long as your mesh collider is suitably low-rez.

Building off what's been said so far, I'd basically encourage you to add more specific detail, going off the OP's pics it looks a bit like an 'impression' of an engine as it were--"this doughnut represents a pump, this cylinder represents a generator, this cone represents an exhaust"--rather than the high-jagged way those things tend to look in real life.

[mariohm1311]

Good start!

Don't be scared of polies, KSP is anything but GPU-limited, and a few thousand (heck, a few dozen thousand) faces isn't a problem, as long as your mesh collider is suitably low-rez.

Building off what's been said so far, I'd basically encourage you to add more specific detail, going off the OP's pics it looks a bit like an 'impression' of an engine as it were--"this doughnut represents a pump, this cylinder represents a generator, this cone represents an exhaust"--rather than the high-jagged way those things tend to look in real life.

Exactly. I built it to have some of the details that make it fuctional, but not all of them. Let's see what I can do.

Also, I was sort of waiting for you. I'm sure that if I had done it with tankbutt, you would have told me. No?

[NathanKell]

I would have, yes.

[landeTLS]

This is my first serious engine model. May I receive some constructive criticism?

http://i.imgur.com/6kG2fzy.png

As you can see, the turbopumps are modelled, as well as the Gas-generator loop; so it's a middle point between the Squad models, and the true to life ones. It is supposed to be a Size-1 engine with a thrust between the Skipper and the LVT-30. It will not be thrust vectoring capable, as you can use fins or 24-77s as Verniers. Tell me what you think.

- - - Updated - - -

From another point of view:

http://i.imgur.com/LMrxreE.png

From here you can see the fuel pipe going to the fuel pump, and the oxidizer pipe going to the oxidizer pump.

Its hard to get and to give good constructive criticism but it is a wonderful thing nonetheless.

Here is my criticism(from most to least noticable):

nr 1:

too many cylinder segements. It looks like 24 sides for the main nozzle. with that many sides you will mainly make the model hard for you to work with(ie. Many segements close together) and it wont look much smoother (thanks to smooth shading and small cross section) i would suggest 8 12 or 16 sides. also good for not spending too many polys where it doesnt help the model.

nr 2: cylinder segement numbers not sync between detached parts (the tubes going around the main nozzle) this makes the segementing more apparent even tho there are lots of segements. Detached cylindrical parts should retain the same amount of segements as the main part. Horizontal segement amounts look good.

Nr 3: (related to nr 1/2)No scaling of segement amounts in relation to radius/size. Ie: as pieces get smaller they should recieve less segements. both to reduce polycount and to make the model look more "even". id suggest 12/16 sides for the nozzle, 8 for the mid sized cylinder+touruses on the right (cooling loop pipe?) And 4-8 for the smallest tubes)

nr 4: detached parts with matching geometry wastes uv space. Id suggest joining those tourus shaped tubes to the nozzle and pipe detail. The other intersecting/detached geometry is completly fine.

hope its readable. Im writing on my phone.

Keep in mind this is pretty harsh criticism for a beginner. and more meant as pointers that you can use to become more efficient as you progress in your modeling.

It is a nice model. Better than my first work

[TiktaalikDreaming]

Good start!

Don't be scared of polies, KSP is anything but GPU-limited, and a few thousand (heck, a few dozen thousand) faces isn't a problem, as long as your mesh collider is suitably low-rez.

Building off what's been said so far, I'd basically encourage you to add more specific detail, going off the OP's pics it looks a bit like an 'impression' of an engine as it were--"this doughnut represents a pump, this cylinder represents a generator, this cone represents an exhaust"--rather than the high-jagged way those things tend to look in real life.

It took me a while to come to that realization, but it does seem you can afford to add plenty of visible mesh detail, so long as your collision mesh is moderately simple.

[PB666]

It took me a while to come to that realization, but it does seem you can afford to add plenty of visible mesh detail, so long as your collision mesh is moderately simple.

I have to say that he is right with regard to engines. By definition th whole nozzle thing breaks the no concave surface rule. My design precept is that the collision mesh and visible mesh should be close.

1. facilitates surface mounting. e.g. of bad mesh is the station hub part which disallows surface attachment because of the concave surfaces.

2. I try to come in with a collision mesh under 150 triangles.

With the engine these two are not going to be importent, your collision mesh is essentially the fairing.

But I am still going to push the point of creating an engine that is better than stock, if you need a more powerful engine for smaller payload, just mod a tank to half height an place an adapter tank on top. What is lacking in the game are launch engines of the best efficiency both on ground and space.

I am developing a real hate for the

IPAD keyboard. Got to get my #%^¥£€#% router fixed!

[InsaneDruid]

How can I add faces to something already there? And how can I make some sort of coupler between 8 faces and 12 faces? I'm sorry if I'm bothering you. I'm learning...

How to "insert faces"

Add an subdivision modifier to the model (complete model or separate the parts that should be threated to a separate mesh) A setting of subdivision 1 doubles your polies. For edges that should stay sharp use edgesplit/crease or simply ignore it. Apply the modifier, go into edit mode, edge selection mode, select the new, unwanted edges (for example on edges that should not be rounded) and delete them with delete-edgeloops.

Also, the add edgeloop function (control-r) is handy to insert new edges.

To "couple" between , for example, 8 to 12 faces, merge the appropriate vertices. Easiest on halving the facecount, say 48->24 faces: just select every other vertice, and use edge slide to slide them to the vertices that should remain, select all, remove doubles.

For 12 to 8: if you look from above, you need to merge the double vertices on the "diagonals", see the picture on the left. select the first couple (second image), merge them at center (third image), repeat. Should give an result as shown on the right.

[landeTLS]

Another one:

these are the two i usually use for lowpoly. 32->16 and 32->24 you can reduce the polycount further by eliminating some edges but i like to keep things straight

Edited July 2, 2015 by landeTLS