modeling resolution

[mtylerfl]

Side note: I always make designer layout to include the end blocks for my jigs and never as small as possible I just can not see any advantage making the design small. This is probably why I do not produce my guitars patterns as that seems to be to radical for users. This jig reflects longer is better not unlike my sleds I make. Nice work!



Designing a layout larger (which includes the sled and/or tails for staying under the rollers) is fine. Some folks prefer to do that, and pretty much everyone using a sled SHOULD design the layout larger (i.e., sled jig size) so they can visually position their components within the carving area identical to the sled.

However, in other software like ArtCAM and Aspire, you do NOT want to design a layout in an area any larger than absolutely necessary to contain all the components. The reason is the way many CAM programs handle their resolution of 2.5D models in a layout. The pixel resolution is spread over the entire design surface - not just in a model component itself. A common mistake folks make when first starting out is to design their project layouts over a surface area equal to the entire cutting area of their machine. For example, let's say you have a machining area of 4' x 4', but your project is only 12" x 12". If the layout is put on a 4' x 4' area, the resolution of each model within that area is reduced far below what it was originally designed at. This is because the project is covering only 1/16" of the total area of the 4' x 4' layout.

I've seen folks design layouts with dimensions of a full 4' x 8' sheet of plywood and place a single (small) component/model in that area. Of course, they post on the appropriate forum asking why their carving came out all "icky and jaggy"! Reason - that small component doesn't have enough pixels to use in that huge area, so the model quality is greatly compromised (i.e., becomes very low-res).

Somehow, the CW Designer software doesn't seem to have the same effect when designing "larger". Perhaps it does and I haven't noticed, but since the tails are not adding much more to "take away" pixels anyway, maybe that's why we can get away with it. I don't know.

[hrlevill]

Wish he could but he is at a loss to figure what is going on on my end I sent him my
MPC for a board and he said it worked fine for him. !!! On his machine I even redid my MPC thinking something was wrong with it I got it to.carve correctly once then it went back.to.carving to.deep it is very strange I am.going to.try by passing the jog part and see what happens tried everything else many thanks for your help.!!!

[liquidguitars]

However, in other software like ArtCAM and Aspire, you do NOT want to design a layout in an area any larger than absolutely necessary to contain all the components.

Sorry but this is not a law by any means and a little dated. the bigger the layout only affects index location and nothing more I would guess a bigger job size would allow you to store information not used in the compile and with respect not even related to my post about the CW. :)

[mtylerfl]

Sorry but this is not a law by any means. the bigger the layout only affects index location and nothing more.



It is absolutely true! (Not what you said, but what I did.) In fact, Brian Moran (owner of Vectric and former Lead Programmer for ArtCAM) created a PDF File for download explaining this in detail I can email you a link if you wish. It is a very, very common issue for folks to design too large and reduce the quality of their projects before learning "the ropes" of pixel-based CAM software.

What the heck. I'll post a couple helpful links for you. First link is the PDF. Second link is a short video explaining resolution settings vs job size.

Link 1: http://support.vectric.com/images/FAQ_Images/VectricModelStructureV8.pdf

Link 2: http://www.vectric.org/video/aspire3_5/tips_and_tricks/2_part_setup/2_part_setup.html

[liquidguitars]

Sorry Michael your wrong my friend. there is nothing stopping one to setting the full with of the CNC table as job size.

[liquidguitars]

design too large and reduce the quality of their projects before learning "the ropes" of pixel-based CAM software.

Resolution has nothing to do with job size if your importing 1:1 stl's your logic is off.

[mtylerfl]

resolution has nothing to do with job size if your importing 1:1 stl's

Read and watch those links I posted for you. You will learn!

I'll post a couple helpful links for you. First link is the PDF. Second link is a short video explaining resolution settings vs job size.

Link 1: http://support.vectric.com/images/FAQ_Images/VectricModelStructureV8.pdf

Link 2: http://www.vectric.org/video/aspire3_5/tips_and_tricks/2_part_setup/2_part_setup.html

[liquidguitars]

your kidding me right?

[mtylerfl]

your kidding me right?

Nope. You will be surprised (I guess!). Read and watch, please.

[liquidguitars]

Lets say I have a job size of 24x 24 I import a stl that is 20 x 20 are you saying that this would effect my carving if so Aspire has issues and so much for nesting stls.

[mtylerfl]

Lets say I have a job size of 24x 24 I import a stl that is 20 x 20 are you saying that this would effect my carving if so Aspire has issues and so much for nesting stls.

You won't notice much loss of resolution in that example (loss still occurs). But, let's say you put that same 20 x20 STL on an area 36 x 36. You will definitely be able to see the loss of quality. The bigger you go beyond the actual job size, the more resolution loss you will notice. Again, the PDF explains this very clearly and in detail. the video touches on it and shows an example in the presentation. The video is the "shorthand" version of the resolution vs job layout size. You'll get the complete explanation in the PDF. And, it's not a defect or "special" issue with Aspire...all the major pixel-based CAM software is the same. If you have a job with only vector cuts, resolution is not a concern in any case. It's only raster models, which as you may know, an STL model is instantly converted to a pixel-based model once imported into a pixel-based CAM software.

[liquidguitars]

If I set a job to 36x36 and i place three 10x10 stl space ships on the table to carve because i want to mill more than one at a time it will be wrong ? or course not your logic does not aply to the CW or Aspire in my humble opinion. I guess i ask Jim M.

[mtylerfl]

If I set a job to 36x36 and i place three 10x10 stl space ships on the table to carve because i want to mill more than one at a time it will be wrong ? or course not your wrong.

Quality loss still occurs, but there is no way around this. In your example, you may or may not be able to see the loss unless you compare it to another layout where the single model is placed upon a smaller layout that is just big enough to enclose the entire model. (TIP: Zoom in and take a look at the edges...the larger layout edges will be more pixelated than the single model on the smaller layout.)

Most often, we just accept the loss and the job will come out just fine. In Aspire, if the quality loss is too noticeable for a larger layout, we do often boost the resolution to HIGH or even EXTREMELY HIGH or MAXIMUM to minimize the loss. In ArtCAM, you have the option to set the resolution manually by typing in the amount of pixels for the job. Aspire has five pre-set resolution settings to choose from..Standard, High, Very High and Extremely High, and MAXIMUM.

[mtylerfl]

Please feel free to delete all my posts on this thread the intent was to tell people that I add the tail blocks in Designer. I exported violins all over the world now using the CW and my system why we are talking about Aspire is not the point. However if MT is right about Aspire you could not do nesting at all.

Ditto. I should have kept my mouth shut on this. However, let me be clear...the resolution information I shared is 100% accurate. Nesting is fine of course, as long as you understand the resolution settings and job layout size rules to achieve the best results. Every CNC conference I attend (I've attended over 40 the past seven years) includes discussion and instruction on the issue and importance of resolution vs job layout size as it relates to pixel-based CAM software.

TIP for CNC machines using separate control software: Another way to overcome resolution loss when machining multiples of the same model on a large sheet of material is to make the layout just barely big enough for the single model and output the toolpaths. Then, in your control software, you machine the model, then repeat the the same high-res model toolpath multiple times (with x and/or y offsets from each previously machined area). This "fools" the layout to think it is only machining a small area for each model (ie., the CNC machines the model that is packed with as many pixels as possible, but machines it several times over the full sheet). This is the way the pros do it in production environments when it is essential to keep the raster model resolution at the highest possible level. My ShopBot Controller can do this...not sure about Mach III, but I believe it has the same capability.

[liquidguitars]

MT I think you unfairly assumed a low resolution. however thanks for making me feel like family :)

[mtylerfl]

MT I think you unfairly assumed a low resolution. however thanks for making my feel like family :)


Brandon,

I sincerely apologize if I offended you in any way.

My intention was and always is, to be sure information shared is spot-on accurate. I made no assumptions of low resolution. Resolution loss occurs in all cases in the examples presented, but whether it is noticeable or not can vary, depending upon the job layout size vs model area coverage within a given layout and several other factors.

[liquidguitars]

I was thinking about moving the violin to Aspire for production however I would like to do nesting, it now sounds like a bad idea and i would loose a ton of resolution the work would be flawed and jaggy as you say. Thanks for the warning.

[mtylerfl]

I was thinking about moving the violin to Aspire for production however I would like to do nesting, it now sounds like a bad idea and i would loose a ton of resolution the work would be flawed and jaggy as you say. Thanks for the warning.

Read the tip I posted in #14. You'll be fine.

EDIT: Thinking about the violin design...there are no small details on that model and if you boost your resolution in your layout and place your models in an area just big enough to fit the models (and allow for your hold-down screws or clamps), you shouldn't experience any resolution issues to worry about. I think you probably sand the heck out of the violins after they come off the machine anyway and your vector cutout profiles around the outer perimeter are "pure"...there are no resolution concerns with vectors at all. If you want me to help you with this, please send me the model (or Aspire file with just one violin on a layout sized just big enough to fit) and I can lay it out in multiples on a larger sheet of material for a great result. It will be my pleasure to do this for you, if you want me too.

[liquidguitars]

Ok I looking at the video and the dude said if you are stretching the object 00:100 you loose resolution, I not stretching anything its 1:1. could be we should start a new thread on this flaw.

[mtylerfl]

Ok I looking at the video and the dude said if you are stretching the object 00:100 you loose resolution, I not stretching anything its 1:1. could be we should start a new thread on this flaw.

Not a flaw. Did you read the PDF yet? Full details there. No stretching involved...specifically job layout size vs model size on the layout. I think the stretching example is an analogy to enlarging a bitmap which yields a pixelation. Not a perfect analogy, but was trying to present something lay people can relate to.

[liquidguitars]

I reading it now so lets say I have a 24x24 job size and I place a 8x8 stl in the center I set the project to high this will give me a flawed carving? can you show me this as a JPG?

[Rocketman]

Read the tip I posted in #161. You'll be fine.

EDIT: Thinking about the violin design...there are no small details on that model and if you boost your resolution in your layout and place your models in an area just big enough to fit the models (and allow for your hold-down screws or clamps), you shouldn't experience any resolution issues to worry about. I think you probably sand the heck out of the violins after they come off the machine anyway and your vector cutout profiles around the outer perimeter are "pure"...there are no resolution concerns with vectors at all. If you want me to help you with this, please send me the model and I can lay it out for a great result. It will be my pleasure to do this for you, if you want me too.

What your saying in post 161; that's exactly what most nesting software does anyway. The file sizes would be huge if they didn't.

What really shocks me is your telling us many of the big players take perfectly good STL files and screw them up by converting them to raster. There are several ways you could do that and still keep the resolution high but your telling us that's not the case? I guess it all boils down to keeping files small so programs don't crash trying to crunch the numbers. Or lazy programmers might be another reason. From what your saying I don't think it would even matter how complex the original STL file is, it's going to get crunched anyway. I can have two STL files of a 1" cube for example and one could have ten times the triangulation as the other. In most software I play with the one with more triangles would have a higher resolution and you would not notice the effect unless you enlarged it to a great extent. Some of my cam programs do have a harder time loading STL files with a high triangle count and I have to lower resolution to import them. Sometimes that more of a limitation with my computer rather than the cam program I'm running. Sometimes it's a graphics card limit more than anything as a lot of those processes are handed off to the graphics cards these days. Also it may be a problem with either Open GL or Direct X depending on which platform the program designer decided to use. Lots of variables but like most programmers one thing remains the same; the saying among programmers used to be "garbage in = garbage out!"

Brad

[mtylerfl]

Hi Brad,

You are stating many of the concerns/questions I've heard countless times before. People are perplexed why pixel-based CAM software behaves in this way. Unfortunately, this is the norm. I wish it were not! We, as designers, must be aware of the resolution limitations of pixel-based software to assure we achieve the best result possible. I hope that someday, ALL CAM software can somehow be resolution independent, but this is not the case today.

As long as you have at least a reasonable understanding of the resolution tips put forth previously, it is unlikely to cause you any major problems. Here is yet another tip if you are creating models from scratch yourself...when you make the model, make it twice the size you anticipate using it in an actual job layout. This way you can "pack it" with more data points from the get-go. The PDF link posted previously explains this in more detail. I often follow this procedure (but not always, even though I probably should).

Just an aside, after I create a model and export it as STL, I choose the triangulation tolerance setting to 0.0001". As you can imagine, this can result in a very large file size. But, I often use the free MeshLab software to remesh at 67% or sometimes 50% reduction. This does a good job of reducing the file size without too great a hit on the detail (usually no noticeable hit at all). Having said that, I usually use the original STL (the larger file) when I import the STL into the CarveWright STL importer for conversion to a PTN file. It just depends on whether a file is going to be "too large" for the importer to handle or not. I have found a file size larger than about 99 MB can sometimes crash the importer, so if I run into that, I'll use the remeshed file to import for conversion instead.

I hope this is helpful!!

[liquidguitars]

when you make the model, make it twice the size you anticipate using it in an actual job layout. This way you can "pack it" with more data points from the get-go.

Hi MT are you saying that I should scale the 3D model 2x bigger" not talking about tessellation" and then scale the raster down 50% in Aspire? This sound like a good thing to try.

[mtylerfl]

I reading it now so lets say I have a 24x24 job size and I place a 8x8 stl in the center I set the project to high this will give me a flawed carving? can you show me this as a JPG?

I just saw your post! You can easily do this yourself (if you have access to the Aspire software), but I will create some examples for you at various resolution quality settings.

[mtylerfl]

Hi MT are you saying that I should scale the 3D model 2x bigger" not talking about tessellation" and then scale the raster down 50% in Aspire? This sound like a good thing to try.

If you have the original model and software it was created in (are you using LightWave?), it might have some benefit as described in the PDF. But, the PDF is actually making the recommendation if you are creating the model in a pixel-based modeling program to begin with, I believe. I don't think you are using pixel-based modeling programs to create your models. But you are right...this would be a good thing to try.

[liquidguitars]

Yes Lightwave...yes we are OT.

[fwharris]

Attention FW...may I suggest moving the 'resolution portion' of this discussion to a separate thread, if possible?...maybe entitled "modeling resolution" in the third party software section. I'm still feeling badly about the hijack I caused.


I think I did it right!! :)

[mtylerfl]

FW, thank you for moving the thread to here!

[liquidguitars]

Thanks Floyd!