how to approach this hood?

[EquiNOX]

can you show me what you've tried so far? Try one yourself and from there I'll see if I can help you.

[cheasie]

I was trying to make the hood but realized even the less fancy ones are hard to make. I used Shear to adjust the curverture of the some parts and blend the surface between them. It didn't turn out well though.

http://img220.imageshack.us/img220/1038/hood1ev2.th.jpg (http://img220.imageshack.us/my.php?image=hood2tx5.jpg)http://img220.imageshack.us/img220/1038/hood1ev2.th.jpg (http://img220.imageshack.us/my.php?image=hood2tx5.jpg)http://img178.imageshack.us/img178/903/hood1ck7.th.jpg (http://img178.imageshack.us/my.php?image=hood1ck7.jpg)



http://img220.imageshack.us/img220/1038/hood2tx5.th.jpg (http://img220.imageshack.us/my.php?image=hood2tx5.jpg)

[EquiNOX]

You started off very good, I am impressed.... There are so many ways to achieve hoods with nurbs depending on which cars you are going to model. So technically there are no golden rules for it.... as long as you can try to get one to look identical. I can tell you one thing, your front/middle part hood need to be even as to the both ends. See attached for clarification. I also attached you second image of my step by step drawing, giving you some idea how you could achieve it... I could post you my work in .3dm but ATM I am very busy.

[cheasie]

thank you equinox, i will try it and post the result

[cheasie]

here's what I have, I just move the control points of the splitted center curve to match the side surfaces in the front. Is there other better way to line up? I am getting the idea on making the hoods but still can't make them look good.

[Snecx]

Found some time and spent a while on the hood of the S550 in your first post. I did not work from blueprints so the shape are all very rough and sometimes funny. Nevertheless, hope these helps.

Btw, I love to solve complex surfacing problems with production cars. This is also a reason why I would suggest people to stay away from fictional car until they can do real cars properly--you won't bump into any complex surfaces if you jump straight into "designing" your own car.

This is what I have done:
http://img145.imageshack.us/img145/9470/hood01co9.jpg (http://imageshack.us)

Step 01
http://img141.imageshack.us/img141/7100/hood02hd0.th.jpg (http://img141.imageshack.us/my.php?image=hood02hd0.jpg)
Started off by doing the profile curves of the car. Quite close to what the S550 has but far from accurate of course. My experience with NURBS modelling is that you can't build surfaces and then adjust it to fit. It does not work that way.

The curves are gonna be very important in determining your surface quality therefore I would suggest you get the curves right before you proceed with surfacing. If anything goes wrong, most of the time you will need to redo the curves and rebuild the surfaces.

Step 02
http://img133.imageshack.us/img133/450/hood03pt8.th.jpg (http://img133.imageshack.us/my.php?image=hood03pt8.jpg)
I got the center piece made with <NetworkSrf> and the sides (one big piece) with <Sweep2>. Note that they share the same curve at the back near the windshield area.

Step 03
http://img150.imageshack.us/img150/7158/hood04ys2.th.jpg (http://img150.imageshack.us/my.php?image=hood04ys2.jpg)
I took the profile curve of the center piece, used <Project> to project it to the sides' surface from the top view. (A) is the original and (B) is the projected curve.

Step 04
http://img176.imageshack.us/img176/2568/hood05bv7.th.jpg (http://img176.imageshack.us/my.php?image=hood05bv7.jpg)
Use <Pipe> on the new curve, larger radius on the front and smaller on the back.

--Continue on next post, images per post limit--

[Snecx]

--Continued from previous post, images per post limit--

Step 05
http://img151.imageshack.us/img151/5654/hood06ak9.th.jpg (http://img151.imageshack.us/my.php?image=hood06ak9.jpg)
Extend the pipe using <ExtendSrf> so it covers the whole surface area. Then, split the lower surface using this pipe. The center piece of the hood is hidden from view here.

Step 06
http://img89.imageshack.us/img89/490/hood07tk3.th.jpg (http://img89.imageshack.us/my.php?image=hood07tk3.jpg)
Now I unhide the center piece and have the side surface in view. I have deleted the split surfaces and only the side remains.

Here I have extracted the isoparm using <ExtractIsocurve> and then match it to the end of the center piece. You can see the extracted curve in view.

Step 07
http://img101.imageshack.us/img101/8749/hood08ym1.th.jpg (http://img101.imageshack.us/my.php?image=hood08ym1.jpg)
Then I use <Extend> with <Type=Smooth> on the extracted curve. Extended to the end of center surface. This will be used to guide <Sweep2> or <NetworkSrf> later.

Step 08
http://img240.imageshack.us/img240/9772/hood09tv6.th.jpg (http://img240.imageshack.us/my.php?image=hood09tv6.jpg)
Duplicate and split the curves to get the curves (A) and (B) as shown. These curves end at the edges of both surfaces.

Step 09
http://img247.imageshack.us/img247/7830/hood10er3.th.jpg (http://img247.imageshack.us/my.php?image=hood10er3.jpg)
Now I use <Sweep2> to create the blending surface. Manual blend is better than the <BlendSrf> in this case because I needed the two different continuity: Position, G0 for (A) and Curvature, G2 for (B).

Take a note that you should always try to match up the continuity with the ones of the profile curves used.

Step 10
http://img247.imageshack.us/img247/2141/hood11qp0.th.jpg (http://img247.imageshack.us/my.php?image=hood11qp0.jpg)
Results! It has proper continuity, we'll verify that later on.

Step 11
http://img247.imageshack.us/img247/9179/hood12rz9.th.jpg (http://img247.imageshack.us/my.php?image=hood12rz9.jpg)
Since it's far from complete, I have done some manual fillet operations and made the grill just for better comparison. Fillets all have Tangency, G1 continuity. :)

Step 12
http://img247.imageshack.us/img247/5089/hood13rx6.th.jpg (http://img247.imageshack.us/my.php?image=hood13rx6.jpg)
<Zebra> analysis with a fine mesh confirmed that it has the proper continuity.

Alright, I guess that's all. It is quite far from the real hood (http://nanobobano.ath.cx/uploaded/wallpaper_ext_5.jpg) but I hope you get the rough idea.

In the real car modelling situation where you need to model the entire car, you will need to plan your surfaces properly so it'll have proper continuity with the rest of body as well.

[Snecx]

Alright, the 3dm file is attached here. The curves are there in Layer 1, the completed hood on Layer 2.

[cheasie]

thank you Snecx, I will try it today after school :)

[EquiNOX]

Cheasie... Your hood look much nicer than the first one... but between two seprate level of hood the edges is too tight. Maybe the step by step wasn't clear enough but I should have told u to use blendCrv not BlendSrf. To make yourself a note: When it comes to complex car, it is going to take you LOT LOT of time to adjust the shape of car body. You have to plan it ahead very well before you can start. Hey, isn't that the car you are planning to model or isn't that the practice kit for you?

Snecx.. nice tuts, to point out... you can't build surfaces and then adjust it to fit. It does not work that way. Well, maybe you can only if you use edit cp to bend, or bend surface to get it fit. :) Sometimes there are curves that cannot adjust to fit the complex surface for example, The 2007 Audi TT, that I worked on before concept car contest announced... I had to use edit cp to pull in/outward to make skirt to look right... If you look at attached pic...you could see how its hard to create curve to establish networksf or rail sweep, perhaps loft. And this would take forever or is hard to make it precision on each curves.. But generally you are correct, it'd be best not to adjust surface.

Edit: Since I worked on my concept car, I discovered so many ways to achieve complex surfaces and may try redo TT skirt when I get back on to it after complete concept car for contest.

[Snecx]

@EquiNOX:
Yep you are correct. I'm saying generally we should not adjust the surfaces. Most of the time it is the problem of continuity. If you have already matched the continuity to other surfaces, adjusting points near to the edge will spoil it all unless of course you know how to control most of the things.

In your example I see np to adjust the CV points but I would prefer to construct it from curves but oh well I don't know much about that car.

This is just how I learn to model. As I said, "from my experience". I believe with most body parts you won't be able to adjust the surfaces at all. At least from my practices I never found any use of "adjustments". I think it is a good idea to get people to stay away from the poly modelling mindset where vertices adjustments is a norm.

[maxlover]

very nice very nice, i always wanted to make car but side tyre area is very hard for me, can u give tip how to approach that :)

[Kabab]

A trick many Automotive guys use when doing big flatish surface like bonnets is they build the main surfaces much larger then trim back to the profile..

The reason they do this is to remove pinching in edges where they roll off, if you look at the gausian curvature you will see that the corners slightly pinch if you just draw 4 boundaries and use a square or rail.

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