BMW Z4 COUPE - pbman
 

on see ing dilberts car an his passion for nurbs and my absolute lack of passwion for them i decided to try it out. so i found a tut on the net an it happens to be the same as wat dilberts making(i didnt mean to clash)

i done the ferrari tut on this site an wasnt keen on all the methods used but there was some good stuff in there that ill remember

so heres my progress i laid out the curves using EP - is CV curves better?

also take a look at the last pic wen i attach the isopams go crazy unlike all the other times wen i attach the isopams flow and i have the correct settings

http://img524.imageshack.us/img524/8...outcopy8jf.jpg

http://img504.imageshack.us/img504/4...dfender7uj.jpg

http://img460.imageshack.us/img460/3...tfender7tm.jpg

http://img153.imageshack.us/img153/2...hfender7ht.jpg

c&c welcome and advice is greatly welcomed!!

:attn: :bow:

Good to see you giving it a try, By the way, I'm modeling the new Z4 coupe that just came so it's a little different to the tutorial that you're following.

Anyway, to answer your questions. You use both types of curves for different situations. Bottom line, whichever curve you use, try to build it with as few CV's as possible, and as cleanly as possible (i.e. the curve should be flowing with no severe, sudden shifts in curvature). When you use the birail or squar tool, Maya is going to try to follow your curves as closely as possible, which is a good and bad thing. It's good for accuracy, but bad because if you built your curves badly, it'll still build your surface for you, but badly also (like in your picture). Maya doesn't know what your intentions are, so it just follows the guides you give it. You can rectify your problem by either building the curves again, but more cleanly, or by rebuilding the surface using the "rebuild surface" tool. Problem with rebuilding the surface rather than the curve is that you'll lose the construction history from the birail, or square.

There's so much with nurbs that can trip you up, you just have to go through and experiment. One suggestion I'd give is to put the car model aside for now, and work on something a little simpler to get used to the tools. Go through EVERY nurbs and curve editing tool that Maya has, and really get to know what everything does. That way you'll know the best tool for the job to solve a specific modeling problem. There's aspects of the tutorial that you're following that I think could have been done better/cleaner, so it's really all up to how you model, and the skills that you have in your toolbox.

thx for the reply

wen u say 'built the curves badly' wat exactly do u mean?

plz be as harsh as u want i wont be affended

in tthe last pic if u divideit just to the left of the red line both of those geometry's were clean (to me) but wen i attach they go like that

also whats the diff betwenn boundary and square

By building the curve badly, I mean these things: Did you use the correct degree curve to fit the job (1st, 3rd, 5th, 7th degree etc), did you place your CV's uniformly, did you check your curvature in every view port to check for severe curvature channges, did you use the curve editing tool to achieve tangency, did you use the project tangent tool to get tangency with a surface, did you tweak the cv's pixel by pixel to achieve tangency. There's a great deal involved in building a simple curve that is going to be the basis of your surface. Take all the time in the world to build the curves, because they are the foundation of everything you build.

The square tool has better tangency options than the boundary tool. Really, you could get away with never using the boundary tool.

Here's a visual example. Look at the two top curves. Visually they look almost identical right. Now look at the cv distribution of each curve underneath. Way different!! The top curve was made by making a perfectly straight horizontal curve and pulling the middle two cv's upward. The bottom was made by freehand clicking along the shape of the curve to try to match the shape. These two curves are going to produce two very different surfaces. That's what I mean about building every curve correctly.

so what method is better the top or bottom curve (soz for my stupidity but i need to learn this)

i know wen i was placing them it was a pain cos they were really hard to match in all veiw port - i will look into the tangency tools ect

ill probly rebiuld them i dont mind if its gonna be better to look at an means future models will be better - also since i made those in ep should weni remake i use cv? (i am looking into basic tuts for nurbs at the mo)

but i still dont understand how u can get accuracy to 0.001cm with this as placing the curves is still inaccurate ont top of the blue prints

thx

It is always better to have less cv's, so the top curve would be the cleaner curve. Whether they are EP or CV curves makes no difference. They are just two different ways to actual construct the curve, but result in the same product.

The o.oo1 comes from the tolerances built into Maya. If you look on most of your nurbs tools, you'll see a tolerance setting. This is telling Maya how accurate it needs to be when it is constructing the surface. The lower the tolerance, the closer Maya will get to following the curve or surface, depending on what tool you're using. It is not always a good idea to have it set on 0.001, as Maya will sometimes not be able to execute the surface due to limitations in the software. But none the less, the tolerance setting should always be in your mind when using nurbs.

pbman,
don't give up like I did. I too have problems understanding the nurbs curve tool. However,after reading this thread, this gives me hope again. Also, I know there are a few tutorials such as 3D Total which I am going to give it a shot myself. Who knows, maybe we can help each other out.

thx dilberts u really r helping out heaps here

u say to build the curves with as few cvs as poss but wen u rebuild the curve it changes the cv amounts

wen i started that tut i guessed on how to lay the curves out an such screated extra curves where not needed co i could have just use the same one an detach ect. i made the wheel arches usin a nurbs circle and adjusted the edsweep, selected the bottom two cvs and moved them - is this a good way?

i think 1 reason i initaly stayed away from nurbs is the fact i dontlike txturin them i can jst about cope with polys! all the changing to projections and tweakin lots of settin an fillin in the gaps an havin to set txt correct by manually movin the txt is anoyin espc wen i tried to txture blue

i did notice the tollerence settings on most tools an just left it as defualt which i think is 0.004cm which is fine as im doin this more for the knowledge than the final look - it will make good pratice for me since the only BIG thing i have done in nurbs is wen i made blue here

thx junkyBob for ur support - i have been usin 3dtotal for tuts but it dont work for me unless i have direct llinks to eack tut so i have to copy an paste them into word:headbang:

iwas playin with the tools last nite an i went over trim again
after projectin and trimming u getthat shape cut out but on the surface it is classed not as an isopam but as a trim edge - what is the diif does it mke some of the tools not work for it

Questions answered:

When you rebuild the curve, or surface, you can dictate the number of cv's or spans in the options for the tool. So Maya will never put in any more spans than you tell it to.

Texturing can be tricky, but all the different tools available can solve 99% of problems.

I think the tolerance is usually set at 0.01 for most tools. And that is a relative setting. i.e. if you have your units set to cm, it will be a tolerance of 0.01 cm. If you have your units set to m, or inches etc. then it will be 0.01 of that unit. Relative, not absolute.

Trim edges are a whole different ball game. There's a ton of techniques to use trim edges correctly and cleanly, but it would take me too long to go over all of them. That's why I'm trying to get around to making a DVD tutorial, so I can actually talk people through the process. Writing just doesn't make things clear enough.

well wat ive decided to do it continue a bit so i can learn these tools but also do research into other nurbs tools

ill probly remakee this or another car afterwards just tryin to get alot done this week as i have it off burt then back to college next week

http://img211.imageshack.us/img211/1374/door3at.jpg

http://img140.imageshack.us/img140/4835/shell3vy.jpg

dilberts - i can seewhat u mean about the curves on mine u can really see where some curves were badly laid

in the tut it tells u to use square but from wat ive read u need 4 curves and select in clockwise/anti direction but it s tell u to do it wen u only have 3 curves?

Like I said, there's parts of that tutorial that I don't think were done that great. If you look at his surfaces, some are a little bumpy. As for the 3 vs. 4 curve question, I never, if at all possible make a surface from 3 curves. There's always a solution that keeps it to a 4 curve patch, you just have to visualize it and solve the problem. You really have to study your reference photos in detail to come up with the best solution, and always be open to scrapping all your hard work if you suddenly come up with a brilliant idea to solve a problem. I can't tell you how many hours I've wasted building a model, only to trash it after a light bulb goes off in my head, and I find a cleaner, simpler method to doing it. Don't be stubborn and impatient to have a finished product. Pick one single surface and focus only on that one little piece until you're 100% happy, then move on to the next.

Anyway, I just done with a 12 hour shift at work (graveyard shift), so I gotta get some rest. I'll check this thread again later today. See ya.

lookin forward to u makin that DVD it would be great if did get the time to do it

well ive changed my mind again hat im going to do is use the curent model to pratice the fillets ect on

ive already started laying new better curves here r some shot their not perfect by a long shot an im still fiddling with the edit curves tool to get each better
ive tried to use as few cvs as possible yest keep it clean an matching the prints

will practice fillets ect later 2nite or 2 moz

http://img297.imageshack.us/img297/8...wcurves8nh.jpg

persp view - it wont resize

dilberts ne comments on the new curves so far ? i really respect ne thing u say wen it come to stuff ilke this

pbman,
if you are going to convert this to polygons afterwards, then I found a web site, not a car tutorial but still teaching you nurbs patching, you do not need to worry about attaching the nurbs surfaces together. Instead, after you are finished patching the surfaces, you can then convert them to polygons and then merge the vertices. The only thing I would still do before converting is to make sure that all your surfaces have been rebuilt so that all the spans line up. I am going to try this on my next model after I finish the one I am currently working on, which BTW I have posted some updates in this forum called 1970 dodge charger finally here and would not mind your comments. Just one thing I ask, be honest, I have taken really harsh crits at school, and I realize it only makes you learn from your mistakes. Also, if you do take a look, please ignore the lighting considering I am just using it to show my progress. However, at the end, I will have a car racing game, fininalized in shockwave, for you guys to play online for free.

i wasnt plannin on coverting to polys but the website sounds useful though

I don't think the site is that useful but maybe you could get something out of it. So here you go...

http://www.3dm3.com/tutorials/maya/head/

like i siad i was goin to pratice fillets and the LFT

but i have hit a wall - i do LFT but wen i render i can see gaps int bwetween the fillet and the body/lofted surface

am i suposed to attach all 3 surfaces or should it be fine as it is cos the tut says nothing bout this

also dilberts u r very knowledgeable on nurbs
i was wonderin how u learnt these as there a book/school or jut fiddling round with all the tools?

thx junkybob ill have a look over that site now

yeah... just rebuild your fillet with 20 by 5 or something like that and the gaps will go away

Nice progress so far :beer:

-Matt

thx matt theman i will try that as this was another reason i couldnt get to grips with nurbs all these gap appearin evrywhere

yeah... well... I dont know about you, but NURBS surprised me! I mean, how easy it was to intersect 2 surfaces and fillet them, or how easy it is to get a really good, simple curved surface without any lumps :)

Matt

You don't need to rebuild anything. You just need to set the render tesselations higher. Select the surface, and then go into the attribute editor in the tesselation settings and increase the curve tolerance to highest quality, and the uv subdivisions to between 5 to 10. The higher the subdivisions, the cleaner render you'll get, but you'll pay the price in render times. Rendering nurbs and controlling the render settings is a whole other topic you'll need to look into. There are a ton of tesselation options in Maya for rendering nurbs, so you just have to experiment.

thx dilberts i will look into that i havent done the rebuild yet so ill tyr this

here it is

i rebuilt the lofted surface as it was a bit low like 4 by 2 or somethin an turned all up to highest and either 5 or 10 i cant remem

test an gaps seem to have gone
was goin for the style of render dilberts does but didnt quite get it

soz bout the AA but it was added time that wasnt needed

looking cool! :)

i agree with wat u said earlier mat theman

nurbs did surprise me in the way u can create such smooth surfaces where done in polys what take a lot of tweakin an extrudin

woot to england!!:attn:
on the subjects of cars i hadmy first drivin lesson book for 2 day the guy neva turned up so i phoned an they say theve lost him an wen they find him he claims he new nothin of the lesson i booked last week

rant over
ne ways

front progress

http://img144.imageshack.us/img144/3...yrender2uo.jpg

http://img214.imageshack.us/img214/3466/4ports5lc.jpg

http://img196.imageshack.us/img196/6885/front32rg.jpg

diff angle

i am so glad i have started to learn nurbs theyr awesome
the way u can untrim an fillet ect

Nice going Pbman, looks really good!

hey dilberts (co u have done this)or ne 1 else can u ans this plz

i was lookin at the grid at the bottom of the car an was wonderin how u create it cos it goes on bout tiny tools but i cant find ne info on them

havent good a render so will post up later

have started on side an doors an r lookin ok

well i didnt want to disapoint so heres somethin i wipeed up in ps

well heres a small update started on the side an i noticed 2 small small piches near the back i still need to clear up

but if i can i save progressivly so i can redo that

http://img122.imageshack.us/img122/5...iewside3kr.jpg

http://img381.imageshack.us/img381/7923/side1rr.jpg

http://img111.imageshack.us/img111/743/sidered5lf.jpg

small update bin workin on the back end

i hit a problem though i used the round tool to round off a corner an save opend it later an the round wsa still there but the suraces were now coverin it but i dont know y

also do they render properly as i get a warnin sayin is not a real suface ; igonred

http://img62.imageshack.us/img62/2214/front42zi.jpg

http://img204.imageshack.us/img204/6687/front55pp.jpg

small vid

i did have some rear renders but i cant find them at the mo

update
 

heres an update
1) im having problems with the round tool i use it the i save an open the fie later an the round is still there but the two patches now r covin it

how /y is this?
http://img237.imageshack.us/img237/8...oolhelp3eg.jpg

2) also how can i attache this back bit to rear thing so it is rounded on the edges - ne suggestion?

http://img278.imageshack.us/img278/3...elprear0fp.jpg

3) heres a rim i made - done with out a tut an its not prefect but i am glad wiv the way it came out - just thought id put into practice wat ive learnt so far
http://img232.imageshack.us/img232/7...aywheel6lp.jpg
http://img237.imageshack.us/img237/1...ywheel20lk.jpg
http://img230.imageshack.us/img230/3...ywheel30tn.jpg

c&c welcome n all things

thx

i still am out ragously stuck with the problem of attaching that rear part ne ideas?

also im tryin to make the disk break - i want to use bevel plus so it will have all those holes in it
but i try an it neva works - i selec the outside circle first - i have tried with dups an original but always fails for reasons like hitory is on or something
or says 1st curve must be outside other curves even wen i select it that way

ne ideas on that also?

many thx

For the rear part I would do this:

Extrude a nurbs circle along each of the edge isoparms (make the circle diameter the width that you want your fillet to be), then create curves on surfaces by intersecting this new "tube" with each of the adjacent surfaces. You should then end up with a strip that you can trim out with the trim tool. You than have to choose a technique to create the fillet tangent to the surfaces with those new trim edges. Tou can try the freeform fillet which works sometimes, or else make a birail surface by creating two curves at the ends of these trimmed surfaces to use as generation curves, and the trimmed edges as the rails. I know it sounds complicated, but I do this so much that when you get used to selecting the correct tools, it takes just seconds to get a nice smooth tangent edge. Bottom line with nurbs modeling is that you have to think about connecting surfaces by creating a new intermediate surface, not by physically attaching the two.

If this confused you, there is a good nurbs modeling tutorial of an Audi TT that some guy did for Rhino software. The techniques he uses can all be applied to Maya, including the one I just described. It has nice pictures, so check it out.

http://www.smcars.net/forums/tutoria...t-audi-tt.html

thx for that dilberts
i hope ur referimg to this part
cos im about to try that

thx man

Exactly, it's a very effective way of dealing with trouble spots.

nicely done pbman its realy coming along

i tried to do the same model but it went horribly wrong. but im thinkin about having another go.

anyway lookin forward to seeing the completed car

:beer:

thx azman for ur kind words

dilberts- i did it and it worked but i would have like more curve on it but thats my fault - u used birail idi u draw the end curves urself an use isopams to do it?

ive been working in the rear lights- at the mo its blocked out
oh an alsh the door handle

update with pics soon

thx

had a little more practice on manual filleting n its 1 useful thing to know so thanks for showing me dilberts :beer: :bow:
heres some more progress - no tut now so flying solo so im taking a while jst to get little things done
-added crude door handle
-blocked out rear lights
-wheel arches started to manual fillet
-added roof but hit a trouble spot still trying to find a good solution but it will come to me

http://img54.imageshack.us/img54/889...rsproof5nr.jpg
http://img57.imageshack.us/img57/424/rearroof5je.jpg
http://img133.imageshack.us/img133/7...ontroof3rc.jpg
http://img216.imageshack.us/img216/3553/sideroof4xz.jpg

crits an comments plz - i dont care if ur rude just speak the truth

thx

edit: BTW this is the soft top version of the car

i wish i had some way to help ..i do like how it is coming along and know how hard it is with nurbs ..keep up t he good work ... i love how this is coming along

thx mmore..
nurbs can be a pain but can be quite nice

only small update i made a cheesey number plate
and made a seat - its not perfect but what the heck:attn:

http://img116.imageshack.us/img116/7...laynamebz4.jpg
http://img70.imageshack.us/img70/661/frontregpn1.jpg

clcik here for a side view of seat in car

clcik here for a rear view

c&c welcome