mesh boolean difference problems

[gantonski]

Hello! I tried researching both on this site and elsewhere on google.. i couldnt find my problem at all

Basically, what i'm trying to do is replicate the temple of concordia and i'm immediately having problems with the columns. Here is an image for reference: http://upload.wikimedia.org/wikipedia/c ... rdia01.JPG

I'm trying to create the concave part of the columns, the flutes. Here is my process:
1. I create a mesh cylinder and convert it into a t spline.
2. I used the array command to repeat smaller circles that i plan to cut out of the column.
3. I've tried various combinations of mesh/t spline/poly surface to achieve a good 'mesh boolean difference' and whenever i do it, the column is converted back to a rhino mesh with an intense amount of faces and edges to where i cant further shape my column to how i want it to look.

i've attached the outcome of it all. ive spent a good part of the day trying to create the fluted look but its just not working in the workspace (the render looks satisfactory) given all the faces and edges that it produces.

its killing me right now that i cant get it to work.

[stratosfear]

Hi

It appears to me that these columns can most easily modeled with basic Rhino commands; extrude curve straight, Transform taper with preserve structure (yes). I don't see any need for t-splines main strength, modeling complex organic shapes. I hope this helps.

[gantonski]

oh based on what you said it seems maybe you missed where i was having troubles.

i can get the taper part down (i was using t-splines for a more organic form).
my problem is making it fluted, with the inset parts. Here is a quick render of what my forms look like (with edges turned on) but without the flute.

so i've attached the image, but clearly its fluteless!

[Chris Botha]

you cannot boolean tsplines. it converts them to rhino surfaces. you cannot convert trimmed surfaces back into tsplines, so you cannot do what you want to do essentially. not with the workflow you are proposing.

i did this in rhino5 beta on macbook.. (damn painfull) but i think you need to go back to basics and work with regular ol rhino to get your result.

regards
Chris

[Chris Botha]

my apologies, i uploaded a much longer clip from quicktime in osx.. apparently it doesnt work too much better than rhino..

anyhow, the workflow missing from the clip as follows. loft from rectangle to rectangle to rectangle to create top. created a rectangle with flutes, copied it downwards, the bottom one i cageedited (3x,3y,1z + scale2d) to make it round. lofted twisted.

[gantonski]

ah very nice chris. Thank you for your help.

Its unfortunate your video cut out right as you were explaining the flutes but your follow up post on here pretty much cleared things up.

But, just to be clear. You made a rectangle and then subtracted other shapes from it to create the 2D geometry of the fluted surface, then copied/loft?

Also, doric columns generally are wider towards the bottom and more narrow at the top, to do this i would just scale DOWN one of the copied items to be lofted, correct?

Thanks again Chris!
-Greg

[Chris Botha]

no probs, reuploading from a windows machine now...

will edit and add to this post in a few minutes

(here ya go, redid vid fropm scratch in betwen scoffing a burger and walking on my treadmill, attempted to upload the Mac OSX version from the macbook via quicktime 3 times, kept truncating it randomnly.. apple.. at least it looks good, even if if cant work...)



excuse the kid playing harry potter on my iphone

now.. fwiw there is no reason you could not use tsplines to generat the entire column in this example.. but.. no point.. hammer nailos with a hammer, screw screws with a screwdriver.

[Chris Botha]

here is the file fyi. the rhino osx version lol. attempting upload AGAIN.. I'm a sucker for punishment..

refuses to upload properly to youtube but vimeo was fine,

http://vimeo.com/27189223

[JSantocono]

hammer nailos with a hammer, screw screws with a screwdriver

Amen!

[gantonski]

Oh wow thats incredible. Thanks so much Chris!
I watched both videos, and i'm glad i did because there was a couple things i didnt catch in the windows version that was more clear in the mac. (such as selecting and deleting points)

I've attached a picture of the column that i made.

I did however run into a small problem.. I attemped to loft from the rounded base then to the square start of the fluted portion, and when i did i got an error saying something about being unable to flute from an open curve to a closed curve, but i didnt design or leave an room for a curve to be open.
Additionally, when i 'got passed' that error, my loft looked goofy i dont know how to explain and i'm not sure i could replicate it, but either way it appeared that when i did the cageedit to the square to make it round, there were tiny little dots that were created in a pattern that lead me to believe it was the outcome of the distorted loft.

BUT!! as you can tell i found a way around all of that (even though i wish i understand where my problems derived from) and came out with an acceptable test column.

[Chris Botha]

well done

at the end of the day all that matters is that you found a workflow. I love watching other people work, i think there are easily at least 5 different way to complete each project i start, with eat piece of software, usually the fastest or best one is the one i think of after i finish the project

rhino compounds this by having many different valid workflows to reach the same point. good luck on the trip, you are well on the way