please can anyone show me how i create a greca jewel like in photo(i wana create it in oval shape no like inphoto .)please if someone knows please help me(only how to create the curves no all the jewel)
thanks billis

Hi billis, please check out Daniele's example in this thread:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1379.1

Let me know if you need additional help after that.

- Michael

no michael its not the same greca.and i dont understand the steps its only a rar archive with the finished example.i want the greca like ii the new photo but in oval shape
thanks for ur attetion
billis

Hi billis - really this is a design that would be easier to do in a different program than MoI because the most simple approach is to draw your pattern in a straight line (just like your image), and then apply a kind of warp or bend transformation to it.

MoI version 1.0 does not have any commands for doing those kinds of deformations.

If you have Rhino, you can use Rhino v4 to do it, that would actually be the easiest way.

I will create some steps to show you the next best solution that you can use inside of MoI though, I will post those in just a bit here.

- Michael

Hi billis, here is the procedure for drawing your design within MoI.

To start with I drew an ellipse:



Then I used the View / Image command to bring your graphic into the MoI viewport to use as a guide (I grabbed the rotation handle and rotated it 90 degrees):



Then I traced just this much of the pattern, using the Polyline command in 2 passes:



Then select those curves, and run Transform / Array / Curve . This will replicate this object around the curve. By default it will place 5 copies around the curve. You will need to change this to a lot more by adjusting the "Item count" option that shows up in the upper-right corner of the screen. Here I adjusted it to 35 items to get a good looking spacing between the objects:



Now for the part that is kind of bit tedious. You have to draw a bunch of lines in to connect these pieces to each other to form a fully closed outline.

To do this, run the Line command, and check the "Repeat" button as shown here:



This will make it possible for you to draw a whole bunch of lines easily, since the line command will automatically repeat while that checkbox is checked.

You need to draw 2 adjacent lines that connect these parts of each piece:



The lines you draw are the red ones, connecting in between the pairs of circled red endpoints.

When you draw these lines you need to take some care to use "end" snap on each one - sometimes there will be an "int" snap nearby the end, and you don't want to get that snap. In fact, you may want to turn off "int" snap temporarily to make sure you don't accidentally get one, you can do that by the little menu that will pop up when you move your mouse over top of the "Object Snap" button in the bottom toolbar. That will put up a menu of all available snaps, and you can click "int" there to uncheck it (or also you can right-click on end to make it the only active type of snap).

Go through and place all those connecting lines in. It's not really that bad, it took me just a few minutes to do it.

Then I selected all those pieces and used Edit/Join to glue them into 2 long curves.

Then I selected the ellipse and used Construct / Offset to create an outside curve a constant distance away from it, that gives the full pattern:



The above curves are attached to this post as Greca_curves.zip .

To build a solid out of these you can select the 2 inside pieces and use Construct / Extrude to punch them out into a solid.

Then I also selected the 2 ellipses and also extruded them, but to a lesser height. Then selecting both of those solids I did a boolean union to merge them into a single solid, here is a closeup view of it:



Is that the kind of shape you were looking for?

- Michael

One other possible way to form the design without drawing all the connecting lines is to have a start pattern like this:



That is with additional lines drawn in, and the lines are extended slightly.

When arrayed, it results in this pattern:



Notice how the ends form a kind of "X" type crossing.

Here is a larger view:



When you have a set of curves like this that make a closed boundary with a bunch of little lines hanging off extra, you can use the boolean Union command on the curves to automatically trim away all the little excess lines for you and leave only the inside.

So selecting all those curves and running boolean union will create this:



However, it is a slightly different shaped design, all the lines are somewhat more rigid within each pattern piece. The other way of drawing connecting lines made those connection lines at a different slope which seemed a bit nicer to me.

- Michael

About this oval
I want to divide the curve ellipse AB in 5 egal parts
I am not sure if this construction is right?
It will be fine if a function Divide a curve exist in Moi :)
There is one inside the helpers but it's just for straight lines :) (used here for draw the circles)
Second image seems better :)
I have used the array / curve with AB as line and AC as Path
So circle's method was false
And now you can draw a perfect Greca motif :)

Ps can we use Array / curve as trusty tool for divide any curves?

Hi Pilou - right now the way to divide into equal segments is to draw one point object (under Draw curve / More), and snap it on to the curve. If your curve is open, place it at an end of the curve, if your curve is closed just put it anywhere directly on the curve.

Then select the point, and run Transform / Array / Curve.

Pick your curve as the path, and then set the Item count to be the number of segments you want. If you want to divide the curve into pieces of a specific length, enter that length as the "Distance" value here instead.

Then push Done and you will have points arranged on your curve marking the different sections.

Then to cut the curve, select the curve and run Edit / Trim, select the points as cutting objects, and push Done to keep all the pieces, and you will have your 5 equal sized pieces.

- Michael

:)
so that answer my question in the previous posted in the same time :)
< Ps can we use Array / curve as trusty tool for divide any curves?

but maybe an automatic tools in the V2? Add that to the wish list?

> but maybe an automatic tools in the V2? Add that to the wish list?

Yup, I would like to add a Divide function that handles this more easily.

Please add it to the wishlist.

- Michael

Sure : I will go in a minute :)

michael thank u.but ur method mathimatick its not corect because the parts of maiandros u have make its not have the same diastance.i have ataach a photo with a correct desighn hoo we make in my job please take a look and tell me if u can help me
thanks billis

< its not corect because the parts of maiandros u have make its not have the same diastance.i
So it's for that I made the little construction above! :)
You must draw by hand 1/4 of the oval motif and then make some mirror symmetry :)
As you see on your model curves up and down are curved!
And even some down curved lines have not the same measure on the angle of the oval than on the side!
You must draw by hand one by one with some helpers lines like in my little construction :)
It's not a speedy work if you want this exact model :)

> its not have the same diastance.

The distance between each piece of the pattern is the same along the inside oval which was used as the path curve for the array.

But since the pattern is "rigid" and does not deform, the outside part will have different distances as the angle changes when you travel around the oval.

As I mentioned previously, MoI does not currently have any automatic method to deform the shape, which seems to be what you want here.

You have a couple of options - you can use a different program than MoI that does have those kinds of deformation tools.

Or if you want to stay inside of MoI, you can create a reference image that has the proportions you need (like the blue one you attached above), and bring it into MoI's viewport using the View/Image command and then draw your curves using the image as a tracing guide.

Also if you have the correct design as a 2D vector file (like in .ai or .pdf format), you can load that 2D file into MoI. You also could try using a vector tracer like http://vectormagic.stanford.edu/ to convert your bitmap into 2D vectors and then load those.

- Michael