small units Xtreme 5 millipoints, mm

[chaskent]

I have just bought Xara and as my fist exercise wish to draw my Wristwatch facia.

I note that the smallest unitwhich Xara works to is a millipoint, which I assume is a 1/1000 of a millimeter. My Exel works it out, based on 27000 millipoints per inch (Xara's spec), as 1063 millipoints in 1 millimeter.

The point is, that this is a very accurate drawing spec.

I have been trying to draw circles with a diameter of 1.52mm. I have tried this by specifying an elipse of equal Height and Width. I wanted to work in mm but found that the Xtreme changed my Width Height entries and so I created a custom unit of 1 tenth of a Milimeter (which I called a centimil ?!) . That improved things but still if i try to create an elipse 15.2 x 15.2 , Xtreme changes is to 15.8 x 15.2. the difference between 15.8 and 15.2 centimil is .6 centimil which is approx 60 millipoints.

They way I am going about this, therefore, seems to make my drawing 60 times more inacurate than the 1 millipoint spec which Xara gives.

If I want to trying drawing small objects to scale like e.g. wrist watch cog wheels, what it the best way to set up units? and what level of accuracy can I expect?

[Odat]

A millipoint is 1/1000 of a point, and since there's 72 points per inch, a millipoint is 1/72000 of an inch.

In any event, I think you're running afoul of some things here:

1. You can enter sizes in any units you like, as long as you suffix it properly, so you could enter "1mm" to enter a measurement of 1 millimeter. The measurement is immediately converted to whatever your page units are. So if you're using pixels, even though you entered "1mm", it'll say "4.4px" or "0.5in" or whatever.
2. The display for sizes uses the same precision as windows does for things, which is generally 2. So if something is a width of 0.375 it will show as 0.37, 0.376 shows as 0.38, etc. Internally the value is still stored correctly, it's just being rounded for display. You can fix this in the windows control panel, but it does affect all applications.
3. If the scale line widths option is turned on, the size of the outline on your shape is included in it's size in the display. When that option is turned off, you see only the size of the shape. That's the likely reason why the sizes are jumping on you.
4. Something else to keep in mind is that if you have the option enabled to maintain the aspect ratio of items (it looks like a padlock and I managed to draw a line right through it in my shot below, sorry) both dimensions change if you change one, which might throw off your drawing as well. To get around that you can temporarily turn that option off, or size your circle while you're still in the ellipse tool.

Hope this helps somewhat.

[Soquili]

When you type in width and/or height after changing to the selector tool the lock aspect ratio feature could cause the change you are seeing.

Holding down a Control Key when using the Ellipse Tool constrains the ellipse to a circle. Once you have created a circle you can switch to the Selector tool and change width or height with lock aspect ratio active and the circle is maintained.

[chaskent]

Thank you , both, that is helpful.

I set my units to mm and drew concentric circles of 1.01mm, 1.02mm and 1.03mm which showed up nicely evenly separated out.

I think that is pretty fantastic!

The size reported in the W H box does not display the objects' actual size - is there any where else in Xtreme 5 where I can find the size of a given object to the same degree of accuracy that it was defined?

[Odat]

The size reported in the W H box does not display the objects' actual size - is there any where else in Xtreme 5 where I can find the size of a given object to the same degree of accuracy that it was defined?

The answer to this could possibly sound familiar...

If the scale line widths option is turned on, the size of the outline on your shape is included in it's size in the display. When that option is turned off, you see only the size of the shape.

If you want to know how big your circle is defined as, turn the option off. If you want to know how much space it takes up including the line, turn it in.

Note also that the line is centered on the outline of the shape. So a 1px line width will show 0.5px on either side of the shape, a 2px line width shows 1px on either side of the line, etc.

[chaskent]

It is familiar and I did see what you meant about the sizes being reported as either including or excluding the shape from the outline.

When my cirlces were set with sizes of 1/10mm differences that was fine and I could read the prescribed size from the HW windows with or without line width scaling.

When, however, I was using sizes of 1/100 mm difference (1.11mm, 1.12mm etc) then I think your point made earlier about the windows precision came into play and the Xtree HW windows did not allow me to see which object was 1.11 and which was 1.12 for example.

Is my remedy to change the window control panel precision settings or use custom units? Or does Xtreme have an object properties panel of some sort which would allow me to inspect the more precise measurement?

My question is of academice interest really because frankly its pretty fantastic to be able to work with 1/10mm in any case. It just good to know what you can do when you have some new software to use.

[PhilM]

Xtreme uses the Windows locale settings to control how many decimal places to display in numbers, along with other aspects of number formatting.

You can alter the number of decimal places shown in Vista by going to Windows Control Panel / Regional and Language Options / Formats / "Customise this format...". The setting is in a similar location in other versions of Windows.

Phil