Author Topic: convex object effect (Read 2698 times)

Nez · April 10, 2018, 02:27:59 AM

Hi there! I'm working on vectorization of "Worms World Party" game picture. And I'm pretty stuck in logo letters. I'll attach photos and you can see there is a lot of small light reflections, and I don't know how to repeat 'em.

logo.PNG
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letter example.PNG
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brynn · April 10, 2018, 04:05:40 AM

Welcome to the forum!

There are a few different ways to approach that. One would be to draw the reflections as separate objects. See what I did in the attached dr1.png. Then I added some blur to them.

But another way which makes more sense, is to use a filter, to add the reflections to the whole thing. See attached dr2.png

You'll just have to experiment, to find a filter which does exactly what you want. Let's see if I can find the poster which shows how each filter looks..... Be right back.

Nez · April 10, 2018, 04:09:52 AM

Thank you! Yes, I tried lots of filter, but can't find the correct one. Can you tell me which filter is applied in the middle?

brynn · April 10, 2018, 04:32:30 AM

I used Bevel > Matte Jelly. The attached image shows the settings. So you can adjust the settings, and maybe get something closer to what you need.

But there might be other filters that are better. Starting on this page, with the one called Bevels, Lazur made examples of all the filters. You can recognize the names of the image are the same as the submenu names of the Filters menu. They go on for the next 3 or 4 pages on OCA. So you can browse through and maybe it will be easier than trying one filter after the other.

Edit
Sorry, forgot the link

https://openclipart.org/collection/collection-detail/Lazur%20URH/10406?page=12

Nez · April 10, 2018, 04:37:39 AM

I tried all this things, but in my case all this filters looks so ugly, look. What is the problem, don't you know?

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brynn · April 10, 2018, 04:41:21 AM

Sorry, I forgot the link in my last message. Here it is: https://openclipart.org/collection/collection-detail/Lazur%20URH/10406?page=12

I don't know what's wrong. Can you provide the SVG file? It looks like you might have more than one filter there. When you're experimenting, always be sure to remove the last filter, before you try a new one. You can look at the status bar to find out. Or open Filters Editor.

Nez · April 10, 2018, 04:46:11 AM

Of course, here is svg example... Thank you for your help so much!

brynn · April 10, 2018, 05:32:56 AM

Oh wow! I have no idea why that's happening. I don't see that at all, and I'm using the same version as you. It must be some preference that we have different, but I don't know which one it might be.

OH! I just thought of something. Go to Inkscape Preferences > Rendering. Make sure you have "Gaussian blur quality for display" and "Filter effects quality for display" set for "Best".

Also, if you're using a computer with multiple cores, you can set Number of Threads (at the top) to however many cores you have. Actually, if you don't know how many cores you have, you can set it for 8 (which I think is the highest) and Inkscape will automatically choose whatever your computer actually has.

Nez · April 10, 2018, 05:38:54 AM

Well, I set now all preferences to Best and... practically nothing happens ( Can you attach your svg file with correct filter settings? I'll try to find out what's wrong

brynn · April 10, 2018, 05:51:14 AM

I already tried that. In your file, I set the exact same setting I used for the Matte Jelly filter, and it didn't get rid of those concentric circular lines. Then switch over to my file, and I still see the nice smooth filter.

Let me give it some more thought. Or maybe someone else will know the answer, and they can chime in. But meanwhile, I'll be looking around for the right pref.

It HAS to be some preference that we have set different. I just have to figure out which one

brynn · April 10, 2018, 05:52:37 AM

Oh, well the Number of Threads setting requires a restart. So try restarting Inkscape (close all instances). Maybe that will kick the other options into effect too??

Nez · April 10, 2018, 05:58:22 AM

I don't think that problem with number of threats, it can affect only the speed of render. But I tried, also I tried to play with settings of filter and find out some values that looks much better now. But again it's not smooth bevel, but it's really better than nothing. Thank you for your help again!

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brynn · April 10, 2018, 06:37:45 AM

I found another difference between your file and mine. In my file, I have a bug, where if I use the Live Preview, it actually applies the filter, so that unchecking the box does not remove the filter. Your file does not display that bug.

Well, that probably has nothing to do with the incorrect filter display, but I just thought it was interesting.

I still can't think of where the problem might be. I know you seem to have found an acceptable result, and you're moving on. But I still see this as crippling your ability to use filters, and it needs to be fixed, if possible.

So I'm still working on it

Lazur · April 10, 2018, 12:37:11 PM

Quote from: brynn on April 10, 2018, 04:32:30 AM

forgot the link

More specifically this:
https://openclipart.org/detail/272870/bevels

If the filter in question uses a diffuse filter primitive it generates the experienced lined look -due to the shallow bitrange used in the colour model. It uses the alpha channel as an input to generate a height map, and that can only have 256 levels.
The ever so working trick is adding some blur into the filter chain.

brynn · April 10, 2018, 01:50:15 PM

But why does it happen in his file, and not in my file? Do you know? Need my file to look at?

Edit
attached

Lazur · April 10, 2018, 02:23:51 PM

Didn't check neither attached svg-s. Nor how the original filter was constructed.
Can upload a screen capture of making such a filter manually from scratch.

Lazur · April 10, 2018, 02:55:23 PM

In my humble opinion the object is too small compared to the filter's settings.
Also with the 3D generated by filtering only don't expect much -cusp corners will look off.

Anyway, here goes nothing:

I'd rather draw the highlight shapes manually and add some blurs instead if I wanted to go for an exact match.

Nez · April 11, 2018, 12:36:45 AM

Oh. My. GOD

17 minutes just to add some bevel on one letter!

I didn't even know that InkScape has such complex filter editor. Thank you so much, Lazur, I'll try this technique.

brynn, and what about my ugly filters, really maybe the size of a letter is problem? It strange for vector, but just maybe, I'll try to scale it up

Yes! The size of object affects the quality of filter, what a bug

InkScape, it's a vector, it shouldn't depend on object size at all!

Moini · April 11, 2018, 06:02:08 AM

That's how SVG filters work, they deal with raster representations of objects, so size matters.

Nez · April 11, 2018, 06:35:51 AM

Moini, that's weird

So, filters in SVG is not a good idea as I understand. Finally done it by white lines with blur.

Thank you, guys, for your help! You're really the best, much appreciate!

Lazur · April 11, 2018, 10:36:25 AM

I wasn't at my best at this, however got the conept working.

Keep in mind that blurring is also a filter, even if it can be added by a slider in the fill and stroke tab.

Filters are applied on the rendering level, they do not change the underlying vector content. Raster editors can use the same filters, however svg is about a live rendering whereas a raster editor merges the filtered input into a new raster object.
That has some results:
-You can render a raster image at any given resolution, the output won't look pixelated as it will always match the output resolution.
Theoretically there shouldn't be a difference in the look between different sized renderings of the same filter however there are filters with different looks.
-Rendering is slow. Even slower when you zoom in. Exponentially (except for a few filter primitives).
-Pdf does not support filtering, the result needs to be rasterized upon saving as pdf for preserving the look.

Nez · April 12, 2018, 01:04:49 AM

Lazur, got it, thank you! I thought about rendering and than adding filters in Photoshop, but thought that it's not a good idea, because I need to add filter only to a single object, not the whole picture

brynn · April 12, 2018, 11:53:04 AM

Well, there's still a problem with how Nez's file (the one attached in Reply #6) is displaying filters. When I scaled that image to the same size as mine, is did not fix that bizarre concentric circles issue.

But if Nez is happy with results (maybe he started a new file, and the problem is only in the other file??), I'm happy!

Fwiw, I think Inkscape could do better about identifying which filters work better on which size/shape object. Some of them look great on small text or narrow objects, but put the filter on a large object, or vice versa, looks awful. I don't think it's a matter of making the filters better. They just need to be identified by what kind of object they are intended to work with.

Especially a lot of those filters which are supposed to look like different kinds of metal, really only look decent on huge objects. But apply them to text, and the filter effect practically obliterates the text! The problem is that text is often where we want to have a metallic look.

But anyway, work is apparently underway on a better filter editor. And once we have that, we'll have a lot more people making filters. And then maybe we can reorganize the menu, and make it more clear how to use each filter.

Nez · April 13, 2018, 02:18:17 AM

brynn, can't say that I'm really happy with the result, but anyway it looks pretty similar. You can check attached file and compare

I made it by curves and blur. Yes, filters are not perfect in InkScape for now.

brynn · April 14, 2018, 02:16:08 PM

That looks pretty good to me. One thing I learned when trying to recreate a raster cartoon image in vectors, with Inkscape (few years ago). The only way I could make it look really very close to the raster image, was to give the vector file just a tiny bit of blur, to imitate the raster. If I recall, it was something between 0.1 and 0.5 for the blur value. Really hardly noticable, but it made it look more raster-ish -- if that's your goal.

(Note that the simple blur is actually a filter. But apply to the whole image, instead of individual pieces.)

I do notice a couple of small differences, besides the tiny bit of blur. It looks like the raster version has a stroke around the eyes of the pink characters, kind of a light blue-gray color. It's either missing in your vector version, or just not as wide.

The red headband on one of them - it looks like the whole headband has the color of the stroke of the raster headband. So the vector headband doesn't have a stroke, and doesn't have the same color as in the raster version.

I see a couple of other places where there isn't a stroke in the vector version. Around the island and the water, in the background (if that's what those are?). (I'm not familiar with the subject.)

Well, maybe those details aren't important. But fwiw