How to modell an engine

[Boosterspice]

Hi people

I really don't know how to model an engine in blender, so I hope that some of you guys might know. I'm not asking for a complete tutorial, but techniques and what tools to use. I have some experience, so no need to go complete newbie-info

[trekkie_]

I'm not sure anyone can help you with this. if you've gotta ask what tools to use, you probably need a lot more experience. remember these are KSP forums, not how-to model forums. while people give some help, modeling from the ground up really isn't the scope of these forums. even 'techniques' is vague and vast. that might as well be asking for a complete tutorial.

just come up with a design, even if you have to sketch it first. if it looks right, model it.

what it really seems like you're asking is how to make common engine shapes, but that is vast and subjective, and really all anything you model, is made up of simpler shapes combined. it's about the little details, not just basic shapes though. for example, an engine exhaust might be cone shaped...but a simple cone shape will just look plain. so you add something more to it, like tubes and pipes, bands and bolts, stuff like that. maybe you flare out the last 3/10ths of the cone a little for some more detail so it's not just a perfect cone.

most importantly, you need to know WHAT you want to design before even attempting to model it. that generally gives you an idea of what shapes you'll need without having to go through trial and error.

Edited May 9, 2013 by trekkie_

[MalletFace]

If you need any help with it, you do have to be more specific and know exactly what you want. Engine is a word that is pretty vague in terms of imagery. I am sure many of us could help you with the steps to make it, or we could direct you to the proper Blender forums, as long as we know what to explain.

[Zaeo]

First, you want to pick a style. Once a style is in mind, go wild. I make 4-6 revisions to each model before I release mine. *Technically, none of it is released.*

from there, its completely trial and error. Modeling is an Art, and there are almost infinite ways to achieve a final product.

As for figuring out what everything in blender does, THAT is where we can help you.

For example, loopcut and slide is my favorite tool for symmetry edits.

I also prefer working with a full model rather than a half and then mirroring it, personal preference.

Anyways, good luck! Can't wait to see what you make!!

[frizzank]

Start off with reference..

What do the current KSP engines look like?

You could start with that and then make your own artistic tweaks to it to get what you want.

Also I find it extremely helpful to get as much reference as possible. I often have several photos full of photos of what ever im trying to create.

As well as knowing what all the pipes and pumps do on actual rocket engines. Here is an example from the Titan III SRB

The tiny orange rockets on the side of the titan SRB's are actually how the SRB's vector its thrust. They inject fuel into the exhaust at different points so it will divert in different directions. This gives it some more detail and also has a real function, helping ground it a bit in reality.

Edited May 9, 2013 by frizzank

[Boosterspice]

Thanks for the tips, all of you! I'll be trying out different methods, but you guys have given me an idea.....

Zaeo, I'll give you a hint: Salami!

[Cryocasm]

Think with portals. If you do a bit of research on the physics behind it you can begin to a get a feeling and imagination for what a different nozzle shape does and how it releases thrust according to its fuel.

You've probably noticed that SRBs are usually broad cones with a wide throat, this is because the burning hot thrusting exhaust is coming from within the SRB, and isn't being mixed up in the combustor/nozzle. In Liquid engines, the fuel is either combusted and then throated into the nozzle, or combusted in the nozzle itself. In order to maximize the area which can pickup force from the reaction as well as orient the thrust beam nozzles are usually "cone" shaped, but actually they are more parabolic than conic.

Some engines also have additional small tanks near the nozzles on gantries and strutting, these can add visual touch, and in real life usually contain cooling liquid or a hypergolic reactant pair, in order to restart the engine in space.

Looking at many liquid engines also makes you find that they often have a ring around the nozzle, this "ring" or "tube" is actually for cooling, which adds nice detail.

When working in Blender, choose the depth of your engine carefully, so that you don't have to do any funny stuff in Unity or for placement in KSP. If its thrust vectoring, you need to have 2 models. 1 "anchor" and 1 "gimbal". Accordingly identify it in the part.cfg file. Use ctrl+e to Mark Seams, this helps greatly with easy texturing and UV unwrapping. Here is one of my more recent experiments:

It starts at a 2 meter diameter up top where it connects to other parts, and at the bottom has a 3 meter diameter and a fairly cone shaped engine, this is because its meant to puuuuuuuuuush thrust out at high power and somewhat lower efficiency, its an ascent stage engine.

This engine has staged combustion and is more fuel efficient, while lacking the power needed for ascent, its perfect for intraplanetary flight at good fuel efficiency. This model specifically lacks the hypergolic fuel tanks for restarting, but this is only preliminary. If I remember correctly this engine is 2m in diameter. Any questions PM me, if it concerns the Blender -> Unity -> KSP pipeline or just the physics behind rocket propulsion.