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General Category => General Anim8or Forum => Topic started by: JSmith_DumDumDumDumDum on March 18, 2014, 08:10:08 am

Title: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 18, 2014, 08:10:08 am
hello, anim8or community,

I was wondering if it's possible to create a shape/mesh and then apply it to a bigger shape/meshe, whereby creating in that bigger mesh an empty space in the shape of the smaller mesh. (Take cheese/cake slice and its "hole mazes" as an example: I can simply create a simple subdivided cube or 3D triangle , but I would need to make little holes in it. This would happen through the negative space of various circles being put it in.)

Thanks.

As a small sidenote, would anyone know how to create 1/3 of a cylinder that's hollow? Instead of a full circumference, I just need a 3rd of one. I'm aware that involving the  extrusion tool is part of one way to do it, but that's about it. haha
Title: Re: creating/applying negative space?
Post by: captaindrewi on March 18, 2014, 12:20:49 pm
Think you are talking about boolean subtraction for the cheese problem.check out the scripts/plugin page.
not sure if i understand second issue but do you mean this....
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 18, 2014, 06:58:19 pm
Yes, Boolean subtraction, as I've come to learn, is the rightful terminology for what I am trying to apply to my object.

Haha it's funny that you brought up that shape you're supposing: that's actually the shape I was hoping to apply my "negative space" to. Bur no, that's not what I mean. I was hoping to create a plane that was bent to the shape of a circle. Instead of a circumference going all  the way around, I was looking for it to go only 1/3 of the way. But, actually, I've  decided to dropped that and use a different shape, which I will get to below.

I think it might be helpful to describe what I'm working on and why I need boolean subtraction, which from my current intelligence, Anim8or doesn't have a direct tool for and would have to be simulated through the material editor. (According to this tutorial - http://www.anim8or.com/tutorials/from_users/boolean_subtraction/booleans_2.html). I am created a rook piece for my graphic chess set. The piece itself is pretty much completed, except that I need 8 empty rectangular spaces to be applied even-spaced to the piece's cylindrical tower head, as to create the "top of tower" look that is typical of most crafted rook pieces in chess. I was hoping to achieve this perhaps with a hypothetical "negative" mesh in the shape of a 3d asterisk (8-limb star).
Title: Re: creating/applying negative space?
Post by: CrashDrive on March 18, 2014, 08:39:23 pm
Not sure if this is what you're looking for?
Title: Re: creating/applying negative space?
Post by: captaindrewi on March 18, 2014, 08:46:10 pm
yeah crashdrive i thought that could work and final mesh cleaner than boolean.
though it seems possible with the script.  :)
Title: Re: creating/applying negative space?
Post by: ENSONIQ5 on March 19, 2014, 08:00:16 am
Re the second part of your original post, about creating a part or segment of a hollow cylinder, there are a number of ways to skin this particular cat (as is usually the case with Anim8or).  Below is one way (illustrated in the attachment).

1. Draw a rectangle representing the cross section of your cylinder.
2. Lathe this rectangle around Y-axis to create a full cylinder.
3. In node-edit mode, delete all the bits you don't want.
4. Select the open edges and fill the holes.
5. Voila!

Obviously the method might need to be adjusted for your instance, more complex shapes might need the reconstruction of missing edges before the holes can be filled.

EDIT: I, rather stupidly, chose 32 faces when lathing, so this isn't precisely a third of a cylinder.  30 would have been a better choice as it's divisible by 3.
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 20, 2014, 03:51:37 am
Thanks greatly for taking the initiative to answer that question anyways, Ensoniq5. Though I wouldn't need that for this specific project, it will definitely be beneficial for future projects.  ;) ;)

And thank you CrashDrive and Captain Drew for your guy's assistance as well.  :)
The following's what you guy's have helped me create.

Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 21, 2014, 01:06:11 am
edited out


I feel incredibly stupid. When CaptainDrewI mentioned scripts, I learned that he was referring to the forum, which for some featherbrained reason escaped me, where I found this: http://www.anim8or.com/smf/index.php/topic,2507.0.html; which was the answer to all my questions about negative space all along.

I guess this thread needed not exist in the first place. Then again, I guess I wouldn't have learned about "boolean subtraction" had I not asked. lol

Good day, folks.
Title: Re: creating/applying negative space?
Post by: CrashDrive on March 21, 2014, 03:27:59 am
It never hurts to ask. Glad you found a solution.
Personally I don't like the messy results from boolean subtraction, but it will create you're bishop slit quickly.
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 21, 2014, 04:53:52 am
Oh hey! You read it before the edit-out. haha

Actually, not quite yet, CrashDrive. I'm still not quite sure how I'm supposed to execute these scrips. I know I'm supposed to put the scripts in a preferred folder/directory, prompt that directory in file->configure and then run it in scripts-> run scripts. I selected the two pieces that I want to apply the boolean operation scripts to before running it, but after I ran it, I was returned with an error message, "Boolean Operations Script Failed! Error #3: A concave shape detected." Then, after closing the error message window, anim8or automatically exited.  >:(

Title: Re: creating/applying negative space?
Post by: CrashDrive on March 21, 2014, 06:48:52 am
Since I really don't use this script I might not be much help on the error, but your setup looks fine.

I modeled a quick top half of a bishop and tried the script. Here's how the slice came out using boolean subtraction.
I also did one with my preferred method the knife tool.
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 21, 2014, 06:52:06 am
Very beautiful piece, CrashDrive. I like the details.
I'll try this knife tool, but I want to know. How did you get the boolean to work withou the error3 message? How would I be able to fix that on my end?
Thanks again.
Title: Re: creating/applying negative space?
Post by: CrashDrive on March 21, 2014, 07:11:25 am
Basically I did the same as you. I selected one then the other and ran the script. There's actually two,
A-B  and  B-A.  Not sure which I used, but I know it took a couple of tries though. I can only assume there
is a problem with bishop mesh to cause an error. Sorry I can't be much more help on that.

Using the knife comes with it's own set of problems, and a bit more work, but the results are much better.
My bishop started as a single  24 x 16 sphere.
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 21, 2014, 04:17:06 pm
Piece completed.

Thanks again, CrashDrive.

Title: Re: creating/applying negative space?
Post by: captaindrewi on March 21, 2014, 05:10:48 pm
Strange, i tried both methods but my results were awful,i have huge distortions around the 'mitre' edges nothing like the crisp edges that CrashDrive has obtained.
 
Title: Re: creating/applying negative space?
Post by: CrashDrive on March 21, 2014, 06:32:52 pm
JSmith_DumDumDumDumDum , hope it turned out okay for you.

captaindrewi, haha, I don't think you tried hard enough. I've seen your great work.

Here's my file .... a few 5 sided polygons are not a problem on this type of model, but are neatly disposed of if necessary.
Title: Re: creating/applying negative space?
Post by: captaindrewi on March 21, 2014, 08:14:32 pm
Thanks for the look of your file CrashDrive.I thought I would have to subdivide the meshes I created to achieve the smooth rendered look but realise now there is no need...errm i could have remained befuddled for quite sometime without your help.  :-[
what next?the knight :-\
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 22, 2014, 02:38:10 am
I wish I only knew what was causing the "concave" problem on my end. It seems that the example that CapatainDrew posted has a slightly concave slant where he placed the slit.
I guess something's we'll just never know. (right away)  ;D
Title: Re: creating/applying negative space?
Post by: CrashDrive on March 22, 2014, 04:22:17 am
captaindrewi, ya it would be a tough one subdividing that without a few wrinkles.

JSmith_DumDumDumDumDum,  You're still having issues I see. It seems like everything has a concave error.
What example are you referring that has a "slightly concave slant"?
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 22, 2014, 05:17:14 am
The bishops in CaptainDrew's exhibit. haha  ;D

But, actually, I simply took your Kniving suggestion, and it was sufficient in doing the job: I drew the cutmarks, highlighted all  the squares within in and then applied negative extrusion to those squares to create an inward dent. It was a bit funky, but interesting and creative-looking. I'm simply merely curious as to what this concave problem. was. It was just the bishop head. A lot of other things were able to boolean-combine.
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on March 25, 2014, 02:17:02 am
All Pieces completed

Title: Re: creating/applying negative space?
Post by: CrashDrive on April 01, 2014, 07:07:09 am
The chess pieces look great. Next time if you have a problem like the concave error thing,
you can always post your file and someone will probably find the answer. 
Title: Re: creating/applying negative space?
Post by: JSmith_DumDumDumDumDum on April 17, 2014, 06:19:21 am
The chess pieces look great. Next time if you have a problem like the concave error thing,
you can always post your file and someone will probably find the answer.
Didn't know this thread was still receiving replies. haha Thanks, CrashDrive. I will keep that in mind.

Of course, now that my issue with negative space is done, there's now a new issue with material appearance. Time for a new thread!  :)