NURBS half circle

Good morning,

blendercommunity. I have just started to model around with NURBS. I have figured out that that is the only way of having more control to design.
I want to model the wheel well of a car. So i need to have a perfect half circle. However when i try to delete half of a NURBS circle Blender leaves me 7 control points instead of 5. Those 2 control points at the botton are superfluous in the modeling process. Is there a way to increase the control point number of a nurbs circle at the beginning as you create it?

Greetings from a parallel universe

Mitochondrium

provide sample file and some pics to show problem

thanks
happy bl

here a picture

Attachments


if you delete 1/2 of it you get like a flatten circle!

why don’t you use a mesh circle delete 1/2 of it then use the spin tool !

happy bl

i want to model with nurbs so i dont loose control over what i am doing.
yeah i catn delete 1 half … looks deformed…
what is the spin tool…

thank you for your help

how much precision do you need ?

I mean even with mesh you can still get quit precise
so wondering why a simple tire would need high precision !

Spin tool is used with mesh data and can get as many segments as you want
look in wiki for blender for this tool

thanks
happy bl

Well i am trying to model my own car design from scratch. Without a sketch… lol … i know … but i just want to learn a new good technique before i start to mess around and then come again to the conclusion that there is a good technique missing.
Therefore all this precision techniques that i need.

spin tool looks nice but only for rotational symmetric objects…

Right now im playing around with nurb surafces.
I think i am getting the hang of it… jsut think of your segment or points 4x6 5x4 or whatever.
Only there you can extrude…
and use as few points as possible…
well i care a lot about precise curved lines… they should be mathematically perfect…
so i should use as few points as possible…

don’t think it is easier to use nurb circle to make a tire

search videos on blender for tires making
a few ways to do it depends on the thread you want
but it is circular symmetry so could use the Spin tool

for videos on tire see these

https://www4.bing.com/videos/search?q=blender+tut+on+tires+modelling&FORM=HDRSC3

also threads


have fun

happy bl

That one’s probably worth giving a try. I know I don’t have the prettiest presentation (I don’t have the best setup for editing), but the idea behind it should be sound enough. Lets you model complex stuff pretty fast and keep a fairly clean mesh.

well i think i get pretty decent results with nurbs surface when i use various patches…
i think this how they do it also in the automotive industry…
Now i get very precise and defined curves and surfaces.
No more cellulite… haha


problem is that Nurbs tools are very limited in blender
so hard to work with but Nurbs surfaces do have geometric continuity which is the only tool in blender having this
so it is very powerfull indeed but not easy to work with.

still for a tire I think it is easier to work with mesh and all the tools available
don’t need to be at 1 part in 1000 for a tire !

happy bl

for the wheel well i am going to make a cut/delete after i transform from curve to mesh.
but first comes the modeling…
the problem with manual editing a mesh is that it can be very tedious and undoable. you see every little deviation in a metal surface that is exposed to bright sunlight. Much like a small dent in the metal sheet of a car.

for fake bumps that is why you have UV mapping
can be done with different type of maps!

look at some of the tut on tires there are several ways to do it including UV mapping
and it looks good and it is low poly count

if you do it with mesh with complicated threads it is high res
I got one tire with 100 K verts LOL

happy bl

what do you mean by fake bumps for the tire?

i am making progress with nurbs… really powerful tool indeed…


all the small threads on tire can be fake with a bump or normal map
large bumps have to be done with some mesh topo

should still give a very nice looking tire
but have to learn how to do it

unless you only want very high res model
with 500 K to 1 million verts !

you could use instancing or dupli verts to have copies of tire at different location
should render faster and takes less space.

happy bl