Inkscape Community

Help Using Inkscape => Beyond the Basics => Topic started by: nemecsek on January 05, 2018, 02:31:46 PM

Title: Eiko Ojala's digital paper
Post by: nemecsek on January 05, 2018, 02:31:46 PM

Hi.
I am fond of Eiko Ojala's "digital paper" style.
 [ You are not allowed to view attachments ]
If you cannot see attachments, you find the same image at https://www.behance.net/gallery/7546467/Vertical-landscape (https://www.behance.net/gallery/7546467/Vertical-landscape)
Yes, it is wonderful and completely digital.

I am interested only in the peak's shadows.
Of course I tried to make the same mountains using Inkscape but my results are far from acceptable.

Eiko is great applying shadows that render different paper levels.
The only way I found to do something (not so) similar is to divide the image in a lot of parts (objects), according to the curves I need.

To apply a specific shadow to each part/object:
1) the object is duplicate
2) a drop shadow is applied to the duplicate, changing appropriately its direction and dimensions (to avoid clipping)
3) the duplicate is slightly rotated together with its shadow
4) the duplicate is placed UNDER the original object.
Doing so, it looks like that the original object has a shadow slightly rotated.

All together the job is very tedious and error prone. Not to tell about the visible artefacts where the parts join and need to be covered by special shapes with the same base colour.

My question: is there a way to "detach" the shadow from an object, so it can be slightly rotated independently, without the need to create the duplicate? 

Or is there somebody that can devise another way to create this kind of variable shadows?

Thanks

Title: Re: Eiko Ojala's digital paper
Post by: Lazur on January 06, 2018, 03:54:55 AM

Welcome aboard!

There is no easy way if you use inkscape for this task -modelling the image in blender in 3D would be way more effective as then the light direction can be changed any time.

However it is possible to draw this in inkscape as well.
The base problem is that the lighting is a diffuse light, resulting more blur where the shadow casting part is higher relative to the base plane.
Making shadows crisp and sharp, pointy at the end nodes of a mountain shape, but smudged at the middle.

Interpolating between paths is the only way I can think of to start with the problem.
Atop of that it needs a correct z-ordering and overlapping the objects to visible stitch objects atop the shadows.

Using blurring and some dithering is almost impossible this case as the displacement value should be 0 at the starts of a cut and vary along the silhouette. I suppose it can be done but it would be very resource heavy.

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on January 06, 2018, 09:35:44 AM

It is the answer I hoped not to hear: I was yet hoping for a magic wand   :wink1:

I already tried in the past with Blender but I cannot grasp its interface and logic..
I will give it a second look, even if I would be lot more at ease with Inkscape. I will search for a tutorial to plan the drawing in Inkscape and "3-dimensionalize" in Blender.
 
Thank you a lot anyway, Lazur!

Title: Re: Eiko Ojala's digital paper
Post by: brynn on January 06, 2018, 02:09:10 PM

Welcome!

I'm not completely sure what you're asking.  I'm also not sure what I'm looking at.  Is that actually a really cool card, like a greeting card?  Or is it an illusion created with excellent vector skills?  It looks absolutely real, if it's an illusion.

Are the "peak's shadows" the blue and green papers?  Or do you mean the gray shadows.  Why do you need to rotate the shadows?  Do you mean you want to change the imaginary light source, so that the shadows lie somewhere else?

If you mean the gray shadows, I don't know why they can't be separate, and moved or rotated individually.  If you use a drop shadow filter to create the shadows, then you can't really separate them.  But if you create the gray shadow by making a separate object, you can do anything you want with it.

For example 

-- Duplicate the object twice.
-- Slide one of the duplicates over slightly, so that the distance between the edge of the one on top and the edge of the one on the bottom creates the kind of shape you need to be the shadow.
-- Use either Path menu > Difference or Intersection, or whatever is appropriate to achieve the result you need.
-- Color the result gray, and blur it as needed.
-- Since it's a separate object, you can move it around anywhere you need it

After some scrutiny, if this is not a real greeting card, but entirely a 2 dimensional drawing, they have done some magic with the shadows.  The shadows are variable, having more blur and less opacity at one end than the other, creating the illusion of paper over paper.  At present, Inkscape can only do that with the gradient mesh (no filter at all) (and a ton of skill!).  You would use the same technique I described, to create the right shape, and then instead of bluring, fill it with a gradient mesh and adjust the mesh (this is quite time consuming).  Or you could do both, gradient mesh and a little blur.

There's another way to create a variable shadow with Inkscape.  It's not easy....it seems like a filter could be made to make the variable shadow....  But anyway, using Interpolation, you can make a variable shadow.  However, it adds a lot of weight to the file.  I use to know a tutorial for it, but I haven't been able to find it lately.  If I can remember enough, maybe I can give you steps to do it.

Off-Topic: show

This is somewhat off topic, but I just saw something on tv about a business which creates unique greeting cards, which when you open them, a 3 dimensional object unfolds itself, and pops up off the card.  I remember having pop-up books as a child, where when you turn a page, a new thing pops up.  This example you showed is something quite similar -- again, if it were a real card.

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on January 06, 2018, 02:57:09 PM

Hi Brynn.
Yes, it is a 2D drawing.
Gray shadows are very real and vary according to the "inclination" of paper. That's the effect I would like to obtain.
Thank you for your procedure.

Title: Re: Eiko Ojala's digital paper
Post by: brynn on January 06, 2018, 04:37:41 PM

Aah ok, thanks for confirming, and sorry I didn't understand before.  That is amazing piece of artwork!!

This is a tricky effect to create using Inkscape.  I can't do it at this moment, but a little later tonight, I'll try what I can remember from the old missing tutorial about using Interpolate for this.  I'll probably also have a go with a gradient mesh too.  I'll post my results.

It seems like a filter could be created, to make this effect.  But I don't understand the technical aspects of filters, so I can't say for sure.

Anyway, I'll post again later, after I experiment  :)

Title: Re: Eiko Ojala's digital paper
Post by: Lazur on January 06, 2018, 06:44:21 PM

Quote from: brynn on January 06, 2018, 04:37:41 PM

It seems like a filter could be created, to make this effect.  But I don't understand the technical aspects of filters, so I can't say for sure.

Drawing the paper texture, for sure.
The rest? Pointy shadows would need 0 blurring, and an increasing blurring radius should be used towards the highest parts.
And as blurring cannot take an image as an input just one, manually set value, it means there needs to be several of them, all seamlessly stitched together.
In that vein it is similar to any halgtone filters, but the blurring itself is very resource heavy.
And, like such a filter would be built up from a dozen of those.

Eventually either a multiply blending mode or masking will be necessary if the cast shadow goes over a painted area where the fill beneath changes.   



I'll play with the interpolation idea later too.
(On a side note, the second mountain top is off.)

Title: Re: Eiko Ojala's digital paper
Post by: brynn on January 06, 2018, 08:43:50 PM

Yeah, I kind of had an idea a filter might be hard to make.

Oh yeah, a mask could accomplish the variable shadow!

(Still stuck on other projects, but eventually I'll get there :) )

Title: Re: Eiko Ojala's digital paper
Post by: brynn on January 06, 2018, 11:17:18 PM

The attached SVG shows my example with the gradient mesh.  It could still be tweaked and improved, but it shows the general idea.  You can see that the inability to vary the blur is still a problem.

Outside the page border is the beginning of my test with interpolation, but it isn't finished yet.  Still working on that.

Note that depending on which browser you're using, the gradient and/or blur might not display properly in the forum.  But when you open the SVG file, you can see it.

Title: Re: Eiko Ojala's digital paper
Post by: Teto on January 10, 2018, 12:07:42 PM

I can't do testing for the moment, but I'm pretty sure that the changes of shadows (varying the blur, as Brynn said) can be achieved with the great new tool:  :grm:
Me guess is that after making a duplicate, you can add many B&W gradients with the tool to achieve the effect (with different opacity for each color). After that, the duplicate can be blend with effect and a little blur.  :)

Title: Re: Eiko Ojala's digital paper
Post by: brynn on January 10, 2018, 02:00:22 PM

I did try it, but found some limitations.  The gradient mesh can't make meshes larger than.... 20 x 20.  And in previoust tests, I used that largest size, and found some performance issues.

In this trial, I made an object similar to the mountain shadows, starting with 6 x 6 mesh, but adding another 6.  But even then it was going to take more time than I had to spare that day.  I do think it could be done with gradient mesh, but given a lot of time and patience.  And maybe more skill than I possess  :wink1:

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on January 10, 2018, 03:10:48 PM

Thank you very much everybody! I really appreciate what you are doing, but don't lose sleep for me  :D

Title: Re: Eiko Ojala's digital paper
Post by: Lazur on January 10, 2018, 03:50:57 PM

So far this is a quick test of the concept.
 [ You are not allowed to view attachments ]


Doesn't really cut it in my humble opinion. The banding issue sticks out too much, the dithering needs improvements.

Anyway, attaching the svg as well.

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on January 10, 2018, 03:55:57 PM

It is really impressive!

Title: Re: Eiko Ojala's digital paper
Post by: brynn on January 10, 2018, 05:49:51 PM

Oh, I see how you did the interpolation.  I was trying with the sub-paths perpendicular to that.  But using Interpolate Subpaths LPE, you can't interpolate the style.  With Interpolate extension, you can interpolate style, but you can't adjust the subpaths.

I got pretty close with this, however, I think I made too big of a jump between blur values on the mask.  I think I might need to break up the top section into 3 masks, to really sell it.  Probably any zoom will show where the side by side interpolation groups meet.  Oh, or maybe find a way to make the 2 separate interpolation groups, and 2 separate masks, not meet at the same place.  I think that's the answer -- and certainly not possible in every potential circumstance.  But either 3 masks with 2 interpolation groups, or 2 of each, as long as their borders don't meet at the same spot.

 [ You are not allowed to view attachments ]

 [ You are not allowed to view attachments ]

Oops, forgot to explain.

I achieved the variable blur by using 2 masks for each of the 2 shadows.  As you can see, it gets very tricky.    For the smaller bottom shadow, there are 2 masks on one interpolation group.  You have to adjust the shape of one of the masks so that 2nd mask doesn't mask over the first mask.  That seems to work better than on the larger shadow above (which has 2 interpolation groups and 2 masks - 3 masks might have been better).

The top shadow has 2 interpolation groups, because the straight interpolation between 2 shade of gray did not look natural.  So I made 2 interpolation groups.  The bottom section, takes up approx half the length, interpolates between #4d4d4d (70%) and #666666 (60%) (using the convenient palette buttons for gray).  And the top half goes between #666666 (60%) and #999999 (40%).

Then there are also 2 masks.  Since blur values vary according to the size of the object, it's harder to figure that out.  But generally, the bottom interpolation group is masked with....I think it was 4 or 5 % blur, and the top interpolation group is masked with 5 or 6% blurred object.  Would have been better with 3 masks, I think.

Title: Re: Eiko Ojala's digital paper
Post by: Lazur on January 11, 2018, 04:52:49 AM

Quote from: brynn on January 10, 2018, 05:49:51 PM

With Interpolate extension, you can interpolate style, but you can't adjust the subpaths.

Tried the extension first but the trajectory path couldn't be adjusted so used the lpe.
Then, converted object to path, broke path apart, group objects together, reversed the z-order inside group and used the interpolate attribute in group.

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on January 12, 2018, 10:36:17 AM

While I can understand (even if not replicate perfectly) Brynn example, Lazur's is completely alien to me.

Lazur, would it be too time consuming to post somewhere the procedure you used?
I assume it would be a nice tutorial.

Thank you both for all the time you dedicated to answer my question!

Title: Re: Eiko Ojala's digital paper
Post by: brynn on January 14, 2018, 08:04:46 AM

Ooh, forgot about Interpolate Attribute in a Group.

In my example, I made the paths wider than the area, and just used clipping to deal with the overlap.  But with Interpolate attribute in a group, it might be possible to use the Interpolate subpaths LPE, and...shall we shorten it to IAG (interpolate attribute in a group).

Weeelll....   I was thinking you'd still need clipping to finish off the ends of the paths (which would appear either square or rounded).  But in this case, the ends would be tucked under the object throwing the shadow, on one side.  And other other side, blurred away.  I'm talking about these particular examples of tall mountains, where the shadows are taller than wide.

Hhhmmm....I'll experiment some more, when I can find the time.  If I can come up with anything reasonable, I'll write it like a tutorial.

I didn't open Lazur's SVG file.  But just by appearances, it looks like he used paths which are generally vertical, while the paths I interpolated were generally horizontal.  Did you try opening the SVG and try to take apart?  It's great way to learn!

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on February 04, 2018, 01:08:18 PM

Lazur, you want to make me suffer  :wink1:
Could you tell me something about your procedure?
From the description and the png I cannot understand properly what you did.  :-$

Title: Re: Eiko Ojala's digital paper
Post by: brynn on February 05, 2018, 02:44:21 PM

I can't speak for Lazur, but my guess would be that since he wasn't totally satisfied with the results, he would not be likely to write a tutorial.

Quote from: Lazur on January 11, 2018, 04:52:49 AM

Tried the extension first but the trajectory path couldn't be adjusted so used the lpe.
Then, converted object to path, broke path apart, group objects together, reversed the z-order inside group and used the interpolate attribute in group.

As far as I can understand it myself, he used.....I'm not sure which LPE he started with.  Would have to be Interpolate Sub-Paths.  You can find instructions for that in the manual.

It looks to me like he used paths which are mostly vertical, echoing the side slope of the mountain.  But you should be able to open the SVG file and take it apart.  Start by selecting the shadow, and Ungroup.  Go from there.  Use the status bar when you're not sure what to do.

Note that the person who created that gorgeous image is absolutely an expert graphic artist.  Personally, as well as I know Inkscape, I would not hope to be able to re-create that image.  So this is a very advanced type of effect, especially to be trying to do with Inkscape.

Anyway, after Interpolate Sub-Paths, then "converted object to path, broke path apart, group objects together, reversed the z-order inside group and used the interpolate attribute in group."

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on February 05, 2018, 03:24:15 PM

Brynn, I see there is something strange going on: if you read from the main thread the svg link is visible. If you scroll down while answering it is not. This is why I never saw it! Perhaps in one case it is believed to be a signature and removed...
Thank you! Now I will give a look to the svg.

 [ You are not allowed to view attachments ]


 [ You are not allowed to view attachments ]

Title: Re: Eiko Ojala's digital paper
Post by: brynn on February 05, 2018, 05:41:30 PM

Yes, that's just how this forum software works. If you don't put the attachments inline, they go at the bottom of the message, and don't show in the topic review (yes, I think it's probably something like being recognized as a signature).  But if you use the inline feature, they do appear in the topic review.  The image is showing too, but if it's not inline, the image doesn't show.

To use the inline feature, place the cursor where you want the attachment to show, then click "Insert Attachment #".  And if you don't do that, the attachment goes at the bottom of the message, and doesn't show up in the topic review.

If you don't need the buttons in the full editor, to provide the bbcode, you can use Quick Reply, at the end of the mesage thread.

Title: Re: Eiko Ojala's digital paper
Post by: nemecsek on February 05, 2018, 11:59:13 PM

Thank you Brynn.
I completely missed it. I will give a look to the SVG and see if I can grasp what happened.