Gimp-Forum.net
Beginner - Applying geometry transforms - Printable Version

+- Gimp-Forum.net (https://www.gimp-forum.net)
+-- Forum: GIMP (https://www.gimp-forum.net/Forum-GIMP)
+--- Forum: General questions (https://www.gimp-forum.net/Forum-General-questions)
+--- Thread: Beginner - Applying geometry transforms (/Thread-Beginner-Applying-geometry-transforms)



Beginner - Applying geometry transforms - my nellie - 01-08-2018

I would like to use GIMP for making virtuals of trees' images changing the potting angle, branch placement, the pot etc
If I have one branch which at some point makes a curve at a right angle and I would like to change the right angle to an acute angle what should I do?
I understand I have to make a selection at first. A selection of the part which has to be transformed. Correct?
Then do I have to use some of the transform tools?
Does this thread answer my questions? https://www.gimp-forum.net/Thread-Gimp-selection-tools-for-beginners?highlight=angle

Thank you in advance.



P.S. I apologize for any grammar/syntax errors... English is a foreign language to me...


RE: Beginner - Applying geometry transforms - Ofnuts - 01-09-2018

(01-08-2018, 11:22 PM)my nellie Wrote: I would like to use GIMP for making virtuals of trees' images changing the potting angle, branch placement, the pot etc
If I have one branch which at some point makes a curve at a right angle and I would like to change the right angle to an acute angle what should I do?
I understand I have to make a selection at first. A selection of the part which has to be transformed. Correct?
Then do I have to use some of the transform tools?
Does this thread answer my questions? https://www.gimp-forum.net/Thread-Gimp-selection-tools-for-beginners?highlight=angle

Yes, you have to make a selection... But if you want to make something that looks even remotely plausible, that selection should be the branch and the leaves, and nothing else (in particular, none of the sky behind, and nothing of any other branch for instance. So it can be difficult and depends a lot on the kind of tree.

Once you have a selection it's easy to rotate and you can set the axis of rotation.

Then you have to think about what you put where the branch was, which is another can of worms...

Best attach one of the pictures you have in mind if you want more precise advice.


RE: Beginner - Applying geometry transforms - Espermaschine - 01-09-2018

The result will definitely depend on the level of realism you expect.

Gimp's transformation capabilites are limited at this point of development.
Rotating branches is no problem, but warping or more extreme transformations are probably difficult and the outcome may be lacking.

And it all begins with a good photo.

My first impression was that its probably easier to make an illustration. But not in Gimp.


RE: Beginner - Applying geometry transforms - my nellie - 01-09-2018

Thank you for your time Ofnuts & Espermaschine
I am attaching two photos of the branch in question in order for you to get a clear idea of what I am talking about.
[attachment=1260]
[attachment=1261]
The branch is on the left and you can see the almost right angle it curves.

And the whole tree
[attachment=1262]
Here you can see the said branch is on the right.

As far as realism on the outcome is concerned I am not so eclectic since what I really want is to see how the tree would look after some interventions.
Let me be a little more precise to give you a glimpse of what I am intending to use GIMP for...
Well, I am doing bonsai and in this art (you may be already aware of) we deal with trees which we try to "dwarf" (kind of) and imitate aged trees in nature.
For this purpose we make :
  • often repottings (every 1,2,3 or more years)
  • we remove unwanted branches in order for the tree to fit into the aimed design,
  • we wire and bend branches or manipulate them using other techniques in order to place them exactly where we want them to be,
  • we prune the foliage and/or defoliate the tree,
  • we also change the angle of the trunk in relation to the soil surface and/or the pot,
  • we change the bonsai pots so that they complement the whole silhouette of the tree and a lot more similar things...
So, it is good/helpful for us to be able to look at  and see a photo of what we have in our minds and check how far or within our design the new image of the tree is.

I hope I was able to explain in a comprehensible way... Smile


RE: Beginner - Applying geometry transforms - Espermaschine - 01-09-2018

So what you want to do is get a visualisation of what a future bonsai might look like, right ?

I guess you can make crude mock-ups of photo-edited mini-trees.
As ofnuts alread pointed out, there is a lot of detail and texture everywhere. The plants are photographed on a busy background, etc.

Its seems the Clone Tool will have to be used a lot and maybe a bit of Resynthesizer 'Heal Selection'.
Still, i think its tough and will require a lot of learning.

People tend to overestimate the capabilites of photochopping and think the program is doing it all for them.
Yes, there are master retouchers out there that can work their magic on images, but it takes skill, experience and good programs.

I dont want to turn you off, but dont expect wonders.

EDIT:
so for example, here we have a good image because it has a background with not too much detail. I can remove the branch with the Clone Tool and it will look okay as long as i dont search too hard for flaws.

Positioning that very same branch somewhere else inside the branches is a completely different ballgame, because you have to isolate all the leafs and blossom.
Its especially difficult when you have a background that is not ideal or the lighting is extreme.

[attachment=1264]

Here i have isolated a branch, put it somewhere else and made the trunk longer with G'MIC - Seamcarve.
You can clearly see that its edited, but maybe its still good enough.

[attachment=1265]


RE: Beginner - Applying geometry transforms - my nellie - 01-09-2018

(01-09-2018, 09:19 AM)Espermaschine Wrote: So what you want to do is get a visualisation of what a future bonsai might look like, right ?
Exactly!

... ... ... As ofnuts alread pointed out, there is a lot of detail and texture everywhere. The plants are photographed on a busy background, etc.
So, firstly I need to photograph trees against a monochromatic background. Correct?

... ... ... Still, i think its tough and will require a lot of learning.
Yes, I have already understood this. At my age (65) attempting to start messing around with photo editing programs seems stiff... Smile


... ... ... I dont want to turn you off, but dont expect wonders.
No, no, I am not expecting any amazing results. As you said above, I just want to get those visualizations of how a tree would look like styled in each possible design/form. For my own use in order to enable me to choose the final form of the tree.

... ... ... I can remove the branch with the Clone Tool and it will look okay as long as i dont search too hard for flaws.
Exactly!
I do not mind if the result shows clearly that it is obviously edited.


I have come across some video describing use of the cage transform tool, like this one : https://www.youtube.com/watch?v=IZ6FzIGAWe8
What do you think about that?

Thank you very much for your time and consideration!



RE: Beginner - Applying geometry transforms - Espermaschine - 01-10-2018

Yes, it all starts with a good image.

Good lighting and angle on a single colour background.
Possibly even contrasting.
Ever heard of green screen ? Thats what the guys in the film industry use to make computer enhanced effects in movies (lots of examples on youtube).
When your trees are against a background with a clear and different colour, it will be easier to select the background with a selection method.

Once you got your subject removed from the background it all gets a bit easier and the editing can begin.

I cant comment much on the Cage Transform as i have barely ever used it and i think i heard its buggy. rich2005 probably knows more about this.

There are a lot of techniques you can use, iWarp could be useful for your purposes, to manipulate the overall shape of a tree (here is a video for PS, that uses a similar tool on hair, so you get the idea), but in its current form its limited because the interface is quite small.
Luckily for you, this might soon change with the upcoming next release of Gimp.

You should definitely get the Resynthesizer plug-in and install it - its the magic tool you can use to fill a selection, so that it looks like its part of the image and has many other uses like making a texture of leaves you can use as filling (see image), etc.

I dont think it makes much sense for me to make a long list of all the tools and techniques you have to learn. Its better to learn with one problem at a time. People here are always eager to assist you with a specific case.


[attachment=1275]

^
Again, this is fun, but not looking in any way realistic.


RE: Beginner - Applying geometry transforms - my nellie - 01-10-2018

Espermaschine, thank you very much for your attention and the suggestions.
Although I am a member for only two days here, I can already recognize the helpful spirit of people here.

So, this is a bonsai story for you.
"Goshin" the famous Juniperus chinensis "Foemina" bonsai by late John Yoshio Naka, in training since 1953, donated to the National Arboretum, North American Collection.

[attachment=1278]

[attachment=1279]

As of 2010
[attachment=1280]


And another perspective from Eastman Kodak's Applied Photography Magazine. Issue #41, 1969
[attachment=1281]


RE: Beginner - Applying geometry transforms - Espermaschine - 01-11-2018

Did this tree just get smaller and smaller ?
I thought you start with a small one and keep it small....


RE: Beginner - Applying geometry transforms - my nellie - 01-12-2018

Espermaschine, thank you for your interest.
Bonsai can be created by seeds/seedlings (time consuming), cuttings or layers (time consuming), nursery trees (less time required) or trees collected from their natural environment (best case).
Collected trees get together better attributes for being trained as Bonsai.
Looking at the photos in their chronological order you can see at first the chopping down of the main tree of the composition.
After that you can follow the evolution of that tree and at the same time the assembly of the composition.
More trees were added and a forest was created.