Output resolution and vector quality in Cheif?


Nicinus
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I don't understand how I set the resolution in Chief in order to get proper line quality. I'm working on my plan, exporting it to Layout on an Arch D, and then printing to pdf where I examine the result. I used 4000dpi which was the highest setting but the result is unimpressive to say the least, so I assume I'm doing something wrong. I've attached two screen shots of zooms on the pdf, one showing a jerky dining table coming from the library, and the other a crooked angled line of a roof outline. What gives?

 

Resolution

Resolution2

 

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You may need to provide additional info. What pdf software are you using?  I have used a couple of different ones and have never got that type of result. I now use Acrobat XI. You said that is a screen shot - I assume that you are getting the same results when printing? I am sure there are other users that can help who may ask about your defaults and setup on Chief. All of which may also affect your outcome, none of which I have experienced.

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Are you using Chief's built in PDF or another PDF program. I use adobe and never have any problems using 300 dpi (24x36) but you should be able to use 100 and still be good. That setting really doesn't do anything unless you plan on printing an extra large size print.. What you see on the monitor is 92 dpi and is all you need for that

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It's probably partially me not understanding some of the concepts, but I see these issues already in Layout, even before it's been sent to print/pdf. Have a look at the below for some line work I believe should be better.

 

Riverstone1

Riverstone3

Riverstone4

 

Maybe it's the internal precision in Chief, if you look at this zoom of a roof edge, some of the lines goes of in another direction. It may seem picky, but it does distract a clean drawing.

 

Riverstone2

 

It seems to me that it is related to line weight and the way Chief simulates thicker lines. I used the override of a line weight of 1 and everything looks more straight and circles more round as below. I did run into another issue though, where I seem to have sent two pages differently, as one is hair light and the other somewhat thicker. Both are drawn without jaggedness though, but I can't figure out what I made different. I've included the layout file if anyone would care to take a look at what is different between page 1 and 2? Looking at some of the lines I would guess they have different annotation sets or scale, but I can't figure out where I can find that info in Layout and both takes me to the same view if I double click them.

 

 

Test.layout

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It's probably partially me not understanding some of the concepts, but I see these issues already in Layout, even before it's been sent to print/pdf. Have a look at the below for some line work I believe should be better.

 

 
 
 

 

Maybe it's the internal precision in Chief, if you look at this zoom of a roof edge, some of the lines goes of in another direction. It may seem picky, but it does distract a clean drawing.

 

 
 

It seems to me that it is related to line weight and the way Chief simulates thicker lines. I used the override of a line weight of 1 and everything looks more straight and circles more round as below. I did run into another issue though, where I seem to have sent two pages differently, as one is hair light and the other somewhat thicker. Both are drawn without jaggedness though, but I can't figure out what I made different. I've included the layout file if anyone would care to take a look at what is different between page 1 and 2? Looking at some of the lines I would guess they have different annotation sets or scale, but I can't figure out where I can find that info in Layout and both takes me to the same view if I double click them.

A layout file by itself only open the layout, it does not include the plan file.  Nothing shows except the layout.

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Some objects in Chief's Library are not perfect circles like a CAD circle would be.  In the attached image, look at the CAD circle compared to some of Chief's symbols.


This .pdf was printed at 4000 dpi and 24x36, the highest resolution I can create.


 

post-84-0-37239100-1398623400_thumb.jpg

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I do know that you should make renders as large as you can, on the screen, before you send them to the layout, and use the highest resolution you have available

in your video card. that's the only way to make them better. You have no control of render resolution when sending to layout other then what I mentioned.  Ray traces have complete control of resolution.

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When you print to a .pdf, you are actually creating an image.   The image has a Resolution similar to an image from a camera. Resolution is measured in pixels, not dots.

Using the term DPI, when printing to pdf is a little misleading, since you are not actually creating dots.  You are creating pixels.  The only time the term DPI should be used is when you're referring to a printer that uses dots, like an inkjet.  Since the pdf is viewed on a computer, it's measured in pixels.  For simplicity, we'll say DPI (dots per inch) and PPI (pixels per inch) are the same for this discussion.

 

If you create a pdf 12" x 18 " @ 300 DPI, the resolution of the image is  (12x300, 18x300) = 3600 x 5400 pixels or 19.4 Megapixels

If you create a pdf 24" x 36" @ 300 DPI, the resolution of the image is (24x300, 36x300) = 7200 x 10800 pixels  or 77.76 Megapixels

 

So why specify 600 DPI?  Because if your layout drawing sheet is 12x18, creating a pdf 12x18 @ 600 DPI it has the same resolution as 24x36 @ 300 DPI, they are both 77.76 Megapixels 

I don't see a reason to go higher than 24x36 @300 DPI.  If your layout drawing sheet is small, you may want to increase the DPI.

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Electormen, while I don't pretend to understand all of this I did program some stuff in postscript when I was younger. Normally a vector program like Chief translates it's info into postscript for a resolution independent pdf. For all typical purposes dots and pixels are the same for a computer. Dpi in this case (Chief) really seems to relate more to the interpolation of curves, and the quality difference is dramatic in 72 dpi compared to 4000 if you zoom in. However, Chief is not converting everything into a bitmap when creating pdfs. As you say yourself, a 300pdi Arch D would be 78Mpixels, or about a 624MB uncompressed grayscale file, which even with 99% compressed would be 6.24MB. My 4000 dpi Arch D pdf is 178Kb and if you zoom in on for example text you can see that no matter how much you zoom in, the text is perfect, no pixelization. Same goes for a CAD circle (which has been defined as a circle). Everything else that uses curves is dependent on interpolation, i.e. how many segments the curve consists of. 

 

Back to Chief. Symbols and architectural blocks are highly dependent on the dpi setting and my results got better when I chose 4000. I'm not using any bitmaps though and can imagine that this would possibly generate large files. It seems as if one of my questions on why two pages looks so different is related to scaling of line weight, since when I look at the object properties the annotation set is the same. However, there does not seem to be a way to see what scaling line weight was used after it has been sent? I can't find anything that seems to relate in properties. This seems to indicate that I would really have to tailor to specific printers, whereas I would like to create one high quality Arch D pdf and be done with it.

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Looks more like a screen resolution problem to me.

This is a screen capture of the same table.

It's a lot smoother than yours.

How does yours look on the screen.

 

The 45deg roof one is, I believe pretty standard and is definitely related to the 45deg line and the screen resolution.

I see the same thing

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Let's say your Arch D pdf was a professional 24x36 photograph to be sold in a gallery.  Most professional print labs have a 300 PPI requirement.  Some will accept as low as 150 PPI.  That's why I don't go above 300 DPI in Chief for Arch D. 

Of course the Photograph would be jpeg or tiff, not pdf.  This LINK can improve pdf print quality

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Not a problem at all, Greg, I'm grateful for all help and suggestions. You are talking about something different though, and what can happen after a pdf has been created and if you want to convert that pdf to an image. My issues are in the creation of the actual pdf. The pdfs created by CAD software is typically in vector format, as opposed to for example Photoshop that handles images and bitmaps.

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Some objects in Chief's Library are not perfect circles like a CAD circle would be.  In the attached image, look at the CAD circle compared to some of Chief's symbols.

This .pdf was printed at 4000 dpi and 24x36, the highest resolution I can create.

 

 

This I don't understand, how was the circle in the symbol created then if not with the CAD tools?

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Are you using Chief's built in PDF or another PDF program. I use adobe and never have any problems using 300 dpi (24x36) but you should be able to use 100 and still be good. That setting really doesn't do anything unless you plan on printing an extra large size print.. What you see on the monitor is 92 dpi and is all you need for that

 

It doesn't seem to be that simple. Have a look at the below images, one printed at 4000 and the other at 72 dpi. Looking at these examples the difference is dramatic, and all in the quality of the actual curve and how it is drawn. If I would print from Illustrator and have a really low dpi setting those curves would start to look pixelated like an antialiasing problem, but here the setting really affects the definition of the curve itself. As you can see the lines themselves are very crisp.

 

Riverstone6

Riverstone7

 

This then gets accentuated when one starts to add line weight, all these examples are with the line weight being 1. 

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The issue is the CAD block that represents the symbol you are printing. The Circe that was created was likely derived from the 3D data. If you do a top down view in 3D you should be able to verify this.

 

Ok, that makes sense. Still, what I don't get is the wobbliness of the lines? Even if it is created by a 3D object that object is also conformed by vectors, right? I understand that a curve has visible segments but it should still be clean in my mind. Have a look at similar example from Revit. I've also included an Archicad example but they use another route.

 

Sample1

Sample archicad

Sample revit

 

The first one is a sample chief scene I downloaded, the second ARchicad and the last one Revit. These are all from my previous work so I know they are 3D objects as well, but in Archicad's case the 3D symbol includes a 2D version that is substituted in plans, creating extremely clean drawings.

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You can zoom in on anything real close and get pixilation , we are talking about printing and 300 dpi hasn't gave me any problems. Check out Doug's post.

 

Not in vector graphics. Choose a text and zoom in as much as you can, it will always stay sharp in your pdf.

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A second factor with PDF is the resolution of the end points of lines.

 

For a lower resolution DPI the endpoints of lines will lie on the grid that the DPI defines. For example imagine that you have a 1 DPI grid. At that resolution the endpoints of each line would hit on a 1" boundary. A 10 DPI grid would give you output that is accurate to 1/10th of an inch and a 100 DPI grid would give you output accurate to 1/100th of an inch.

 

The simple answer is that you need to pick a DPI that is suitable for your printer. If your printer is 600 DPI then 600, 1200, 2400 etc. would be good choices.

 

72 DPI is the low end of what would be acceptable for things to be displayed on screen, although these days something closer to 200 DPI would be better given that the current trend is toward displays with higher resolution.

 

Fonts can also be affected by this in that at a very low resolution they will not be placed accurately leading to odd spacing even though they draw smooth.

 

In Chief you can also hand craft the CAD block to represent the 2D, which is likely what other programs are doing.

 

If you zoom in on a PDF or get a magnifying glass out and look at printed output you will start to notice all kinds of odd artifacts.

 

The real question is does it look good when printed?

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