How to draw a bended sheet in isometric view?

[Vince42]

Hi,

I just started playing around with isometric views.

I would like to create a "bended sheet" (that is the best description I came up with, sorry).

So far I did the following:

• Drew a line representing the bending with the pen tool
• Fitted the line to the side
• Duplicated the line
• Drew lines between the to bended lines with the pen tool

So far the result is not spectacular but it shows at least the bended sheet:

 

How can I apply a filling to this? Is there a way to have shadows and such in order to make it look three-dimensional? Is it possible to apply a pattern to the filling?

Any help is highly apreciated (as always)!  

[thomaso]

I am missing an edge at the top and the bottom.

You can fill only closed shapes usefully, so you might need to think and draw rather in background, middle, foreground.

For the shadows: why not analogue: just folding a paper in this way and looking at it in various lighting? Or …

[R C-R]

If I understand you correctly, you have 4 open, unconnected curves, right?

If so, to get what you want, to begin with you need to have 3 closed shapes, one for the front fold, one for the back fold, & one for the main part of the sheet between the two folds.

So minimally, you will need two more straight curve segments for the top & bottom edges of the sheet & then to join them appropriately to get the three closed shapes. The stacking order will determine what is visible from each part.

Hopefully, this is enough to get you started....

[v_kyr]

Well you can (re)use something like this ...

 

Though you would have to better finetune the color transitions, aka make them better as I did just quickly.

• paper-roll-ade.afdesign

[Vince42]

On 7/25/2023 at 11:44 PM, thomaso said:

I am missing an edge at the top and the bottom.

You can fill only closed shapes usefully, so you might need to think and draw rather in background, middle, foreground.

For the shadows: why not analogue: just folding a paper in this way and looking at it in various lighting? Or …

 

I thought I connected all lines and would have something like a 3D object, which I could adjust later on.
But it seems that I will have to go for the back-middle-front approach.

The shadows will be a different story after getting the base model right. Thank you for your input!

[Vince42]

On 7/25/2023 at 11:45 PM, R C-R said:

If I understand you correctly, you have 4 open, unconnected curves, right?

If so, to get what you want, to begin with you need to have 3 closed shapes, one for the front fold, one for the back fold, & one for the main part of the sheet between the two folds.

So minimally, you will need two more straight curve segments for the top & bottom edges of the sheet & then to join them appropriately to get the three closed shapes. The stacking order will determine what is visible from each part.

Hopefully, this is enough to get you started....

I put the edges together, but I am not sure, whether I created a closed curve by doing so - probably not.  

I will test this approach, thanks!

[Vince42]

On 7/26/2023 at 1:39 AM, v_kyr said:

Well you can (re)use something like this ...

[...]

Though you would have to better finetune the color transitions, aka make them better as I did just quickly.

• paper-roll-ade.afdesign

 

This is also intriguing, thank you very much!

I will play around with all the good suggestions now - thank you all very much, you were very helpful!

[Vince42]

Just one final stupid question: Am I seeing it right, that there is no way to have the curve handles for the whole sheet, but only separately for the three (back, middle, front) parts?

[thomaso]

4 minutes ago, Vince42 said:

Am I seeing it right, that there is no way to have the curve handles for the whole sheet,

Yes, there is: If you select all layers of this drawing then an according bounding box appears with the wanted handles.

[Vince42]

12 minutes ago, thomaso said:

Yes, there is: If you select all layers of this drawing then an according bounding box appears with the wanted handles.

But wouldn't that just allow me to resize the sheet? I thought that the curve handles would not be selectable - and besides the curve handles would not know anything about the curve, as they reside in separate segments of the sheet, right?

Thinking about this: I probably would not even need an isometric view then, because the segments would not be aware of the three dimensions ... 

Well, i will play around a bit and see where it gets me to ...  

[thomaso]

12 minutes ago, Vince42 said:

But wouldn't that just allow me to resize the sheet?

"just"? I thought you had that in mind with "handles for the whole sheet". Can you be more specific, for instance with a screenshot? And, just in case, the Move Tool and the Node Tool work quite different, maybe the Node Tool does what you want.

Or possibly you want to merge several single curves of certain areas of the drawing to 1 layer of type "Curves" (plural "s") and thus treat its nodes, its handles, its style accordingly. For instance if you have drawn the foreground lines (the lower, rolled part of the sheet) in several separate curve objects. Whereas merging curves doesn't mean to close open shapes  (e.g. to apply a fill colour).

24 minutes ago, Vince42 said:

Thinking about this: I probably would not even need an isometric view then, because the segments would not be aware of the three dimensions ... 

"view"? If you mean an isometric grid (= guides + according snapping): I agree, for the drawing of a curvy paper you don't need an isometric grid. But not because of "segments would not be aware of the three dimensions" (they never do in a 2D application and are useful exactly because of this limitation). Here this grid appears not required or useful because of the curve(s) and final shape you want to create: while the curved lines don't have to follow any grid the straight lines simply need to be parallel (if within a grid at all) and thus don't require the grid while the Snapping options maybe sufficient.

[Vince42]

26 minutes ago, thomaso said:

"just"? I thought you had that in mind with "handles for the whole sheet". Can you be more specific, for instance with a screenshot? And, just in case, the Move Tool and the Node Tool work quite different, maybe the Node Tool does what you want.

Or possibly you want to merge several single curves of certain areas of the drawing to 1 layer of type "Curves" (plural "s") and thus treat its nodes, its handles, its style accordingly. For instance if you have drawn the foreground lines (the lower, rolled part of the sheet) in several separate curve objects. Whereas merging curves doesn't mean to close open shapes  (e.g. to apply a fill colour).

"view"? If you mean an isometric grid (= guides + according snapping): I agree, for the drawing of a curvy paper you don't need an isometric grid. But not because of "segments would not be aware of the three dimensions" (they never do in a 2D application and are useful exactly because of this limitation). Here this grid appears not required or useful because of the curve(s) and final shape you want to create: while the curved lines don't have to follow any grid the straight lines simply need to be parallel (if within a grid at all) and thus don't require the grid while the Snapping options maybe sufficient.

Sorry for being too unspecific, for sounding disappointed and for calling the isometric grid an isometric view - my failure, apologies.

My original vision was to have one object, bending its curves, putting it to the isometric grid and by all that having a fully fledged 3D model of the bended sheet, that I could easily adjust and change the 3D view on it. The fact that this is not possible, does not disappoint me, it just makes my plans a bit more complicated.

I think I found a solution now that I can work with, thank you all again for all the good advice!

[thomaso]

3 minutes ago, Vince42 said:

My original vision was to have one object, bending its curves, putting it to the isometric grid and by all that having a fully fledged 3D model of the bended sheet, that I could easily adjust and change the 3D view on it.

Ah, thanks for clarifying. I understand the desire but still think this is independent from the use of a grid / its guides.

Just consider that bending (or stretching, shearing, …) happens in 1-2 dimensions only, and, even in a true 3D application you can bend an object without changing its perspective. – Compare bending and perspective:

-

[Vince42]

On 7/28/2023 at 2:35 PM, thomaso said:

Ah, thanks for clarifying. I understand the desire but still think this is independent from the use of a grid / its guides.

Just consider that bending (or stretching, shearing, …) happens in 1-2 dimensions only, and, even in a true 3D application you can bend an object without changing its perspective. – Compare bending and perspective:

 - 

 

Thank you for the wonderful illustrations.  

My task is to reuse the shape in many different perspectives without bending anything.
The "bended" in "bended Sheet" just describes the shape of the desired object, not the use cases.
I had the high hope, that I could create one object, give it a fill, put it to the back (or front) perspective and to change the perspective for every use case.

But as it is impossible, I will work with my little workaround.

[thomaso]

32 minutes ago, Vince42 said:

The "bended" in "bended Sheet" just describes the shape of the desired object, not the use cases.

I did not misunderstand this. I rather referred to the idea that bending would enable, create or support a "true" 3D space to enable simply rotation for a different perspective.

On 7/28/2023 at 2:02 PM, Vince42 said:

My original vision was to have one object, bending its curves, putting it to the isometric grid and by all that having a fully fledged 3D model of the bended sheet, that I could easily adjust and change the 3D view on it.

A bending is required in your illustration for instance in the rounded, rolled ends of the sheet to achieve perspective, a circular shape need to be elliptical (~stretched).

… just like an isometric grid helps to bend (= rotate + shear) three single square shapes to make them look like a cube:

In a 2D app we have only x and y coordinates (to move left-right and up-down) while it lacks in a z coordinate (to move front-back). Here the z coordinate is simulated in the Layers panel only with its hierarchical vertical layer order, whereas all layers remain at the same z level = 0 and just create a vertically arranged impression, for instance by hiding content of layers that are sorted below (e.g. by a fill colour).

[GarryP]

Vince42: You might like to look at a video I’ve just posted in the Tutorials section of the forum: