nebs

Drawing cylinders with the isometric grid in Designer

10 posts in this topic

I'm trying to draw an upright "3D" cylinder using a "2:1 Triangular" grid. I'm able to place the top and bottom circles of the cylinder (see image below) but I don't know how to complete the "walls" of the cylinder.

 

Screen Shot 2018-01-13 at 5.13.25 PM.png

 

My first instinct was to simply draw a rectangle from the top circle to the bottom circle. The trouble is I can't get it to snap to the edges of the circle's perimeter because of the skew that I had to apply on the circle.

 

As you can see, the circle's bounding box is snapping to the grid just fine, but the left and right edges of the circle (where the wall of the cylinder should hit) are not aligned to the grid.

5a5a881bec9f8_ScreenShot2018-01-13at5_28_11PM.thumb.png.8a4f1b22478342ac971330208e401dff.png

 

I'm trying to get something like this:

5a5a88ef54b45_ScreenShot2018-01-13at5_31_56PM.png.e23054b40394a4682f5e7bf2c0ef60cc.png

 

Are there any simple ways of drawing cylinders in this grid? Any tips are welcome.

 

Thanks!

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Since a circle is just an ellipse constrained to have a single radius, it would be much easier if you began by drawing an ellipse that snapped to two of the grid's vertical & angled intersections. That way you don't have to skew anything & you can adjust the height very easily using the top or bottom center control points to set the shape of the top of the cylinder as desired.

 

Then duplicate that ellipse, move it down to form the bottom edge, snap a rectangle to the left & right edges, add the bottom ellipse & the rectangle together, & move that shape below the upper ellipse.


Affinity Photo 1.6.6; Affinity Designer 1.6.0; AP for iPad 1.6.2 (but no supported iPad -- yet!)

macOS High Sierra 10.13.2; iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM 

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Hello nebs,

 

You can follow the method given by @MEB, I have not found the location of the message.

Draw two ellipses, one for the bottom and one for the top, connect them with two straight lines.
Duplicate the ellipses, color them, position them underneath and hide them (in layers).
With the "Node Tool", select the lines, "Join Curves", then "Close curve". Colour the shape so delimited.
Make a Boolean operation "Add" between visible ellipses and shape.
Make hidden ellipses visible and place them on top.

Cylindre.png

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12 minutes ago, reglico said:

Draw two ellipses, one for the bottom and one for the top, connect them with two straight lines.

It is much easier to draw a single rectangle, snapped to (for example) the top left edge of the top ellipse & the bottom right edge of the bottom ellipse, add that rectangle to the bottom ellipse, & move the resulting shape below the top ellipse.

 

You don't need to duplicate anything (besides the two ellipses if you want the top & bottom edges of the cylinder to match) or hide anything.


Affinity Photo 1.6.6; Affinity Designer 1.6.0; AP for iPad 1.6.2 (but no supported iPad -- yet!)

macOS High Sierra 10.13.2; iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM 

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1 minute ago, R C-R said:

It is much easier to draw a single rectangle, snapped to (for example) the top left edge of the top ellipse & the bottom right edge of the bottom ellipse, add that rectangle to the bottom ellipse, & move the resulting shape below the top ellipse.

 

You don't need to duplicate anything (besides the two ellipses if you want the top & bottom edges of the cylinder to match) or hide anything.

Hello, R-C-R,

 

Originally, the @MEB method was applied to one cut, so with two ellipses of different sizes and can be useful for "cylinders" with a different diameter at the top and bottom.

The rectangle is actually simpler for a "perfect" cylinder.

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I was assuming @nebs was asking about what is often called 'right circular cylinders,' which may have been a poor assumption on my part. However, I don't know what method you refer to but in general, there should be no need to duplicate & hide anything when creating simple cylindrical shapes.


Affinity Photo 1.6.6; Affinity Designer 1.6.0; AP for iPad 1.6.2 (but no supported iPad -- yet!)

macOS High Sierra 10.13.2; iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM 

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Thanks everyone for your replies!  The ellipse method is interesting, but how do you make sure the ellipse is properly aligned to the isometric grid?  I can sort of eyeball it but is there a technique to ensure the perspective is correct?

 

I actually found a solution before this question was approved by mods. I ended up divided my two circles in half along the horizontal diameter (which exposed the two nodes along the perimeter). I then used the node tool to stretch out the space between the two semi-circles.

 

5a5b8dc9cf200_ScreenShot2018-01-13at9_21_53PM.png.baedcbb9e10292bd6a65d040e2d30299.png

5a5b8dc927108_ScreenShot2018-01-13at9_21_44PM.png.f4428acac390b176a18d6fe2eb6f0a92.png

 

And finally I added a full circle to create the "top":

5a5b8dc8143e9_ScreenShot2018-01-13at9_21_18PM.png.a51d63381a21bf62e9c516d2268bc369.png

 

It's a little more work, but the circle is properly aligned to the isometric grid.

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8 minutes ago, nebs said:

The ellipse method is interesting, but how do you make sure the ellipse is properly aligned to the isometric grid?

Using snap to grid, there are several ways, but here are two of them:

5a5b996096c99_dragellipse.png.729b20e8dc27a428c1f6326d4ebdb9a0.png

But all that really matters is that the left & right edges of the ellipse end up snapped to a pair of the vertical isometric grid lines.


Affinity Photo 1.6.6; Affinity Designer 1.6.0; AP for iPad 1.6.2 (but no supported iPad -- yet!)

macOS High Sierra 10.13.2; iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM 

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