CATI Tech Notes

Rendering Settings – DPI vs. pixels

Had a question today on how to set the DPI settings for PhotoView 360...

Good question - not really sure…

Off to the SolidWorks Knowledge Base…

Bottom line?  There is no way to set the DPI in PhotoView 360 (or PhotoWorks for that matter).  The concept of DPI is only relevant to printing, not on-screen images.  

Here is the SolidWorks solution that explains it all…

 

Solution Id: S-02581  

Question:

Regarding the PhotoWorks/PhotoView 360 image resolution, rendered output is always 96 DPI, even if set much higher in PhotoWorks/PhotoView 360.  Why?  

Answer:

If the user checks the file properties of their rendered image in Windows, they will see 96 DPI.  This value is saved in most bitmap images, and is generally irrelevant to image processing.  DPI is actually meaningless when referring to on-screen images, these are defined purely in number of pixels.  PhotoWorks allows input of size and DPI settings to help the user generate an appropriate size image.  The following settings would all give an identical output:

20in x 20in at 50 DPI

10in x 10in at 100 DPI

5in x 5in at 200 DPI

1in x 1in at 1000 DPI

These would all produce an image of 1000 x 1000 pixels, with identical file size and detail – the files would be indistinguishable. 

Where the DPI setting is useful is if the user knows he/she wants to print an image 6 inches x 4 inches at 600 DPI, SolidWorks can take this information and calculate that it needs to render an image size of 3600 x 2400 pixels.  The user can experiment with this by inputting a size and resolution in the Render to File dialog, then switching back to Pixels to see what size image will be generated.

 

Nathan Brunner, CSWP

Technical Analyst

Computer Aided Technology, Inc.

Maximizing SolidWorks Performance

Well it's that time of year again and my team and I are preparing for SolidWorks World 2011.  My team is doing several presentations this year but the one closest to my heart of course is the one Josh Altergott and I are doing together called Maximizing SolidWorks' Performance.  This is the sequel to a presentation that we did last year that was very well recieved.

The premise is this; we got a very nice brand new Dell Workstation to test on.  We built a very large assembly as a test subject.  And finally we wrote a macro that would do a bunch of different operations to the assembly and components to the assembly.  All of these items establish our environment.  The stats are listed below:

Baseline Machine

• Dell Precision 5500
• 6GB RAM
• Dual Core Processor
• 7200 RPM, 1 TB Hard Drive (For file storage)
• Nvidia Quadro FX 4000 Graphics Card
• 3 10000 RPM, 320GB Hard Drives RAID 0 (For OS)

The Baseline Assembly

• 6637 Total Components
• 5862 Parts
• 775 Sub Asseblies
• 170 Top level mates
• 13011 Bodies

What are testing consist of, is changing just one aspect of the environment or modeling methodology and measuring the time difference that is takes for the macro to run vs our baseline.  Our baseline test took 7 hrs and 50 mins to complete.  We are also able to breakdown the benchmark into different categories of operations to better tell what changes effect what types of efforts in SolidWorks.  Aspects that we are measuring include: file opens, closes, saves, modeling, rotations, rebuilds and others.

Some of the things that we are comparing are:

• Different amounts of RAM and different numbers of processors and cores. 
• 2010 vs 2011
• having files saved in the old version vs the new version
• Verification on rebuild turned on vs off
• Files stored on the network vs local
• lightweight vs fully resolved
• optimized user settings vs default
• Different hard drive options
• Different RAID options
• differnt modeling methods
• and much more....

As you can imagine, we are learning a lot from this effort.  We are very excited to present our findings at SolidWorks World and we are hoping that, if you are coming to the event, you will join us for our little portion of it.

Maximizing SolidWorks Performance

Tuesday, January 25, 2011 @ 10:30am in Room 202

I hope to see you there

Adrian Fanjoy

Technical Services Manager 

Render Contest.com a fun competition

 This last month I finally got make a submission to the PhotoWorks/PhotoView 360 Rendering contest at www.rendercontest.com.  This contest used to be hosted by Rob Rodriguez at http://robrodriguez.com. It is now hosted by Chris Thorn, a SolidWorks user for several years.  He like your feedback on contest.

 

With that, more about the contest.  Each month a SolidWorks model is selected to be rendered in either tool you would like in the SolidWorks suite of tools, PhotoWorks or PhotoView 360.  You have 30 days to render and submit your models.  At the close of the contest there is five days of voting open to the public.  The winner is then announced and the winner's entry is placed into the Winner's Gallery.

I've done my share of rendering over the years in SolidWorks, 3d Studio, Maya, POV-Ray and many others.  With that I've acquired a pretty good knowledge of the technology and techniques used in rendering.  So, today I'm starting a new category here at blog.cati.com, PhotoView 360. 360 will be our vessel of choice over the next few months, but the topics will lean more towards rendering in general.

We are going to cover topics such as preparing your model, materials, environments (HDRI and Non), outputs, and post production. I hope you enjoy it.

At the beginning, middle, and end of this I hope you take the time to download and try these techniques on the models at www.rendercontest.com. Upload your images, get feedback, and be creative.

I'll close with what James Cameron (YES the AVATAR guy) said at SolidWorks World this years. Follow these and submit your renders.

Hope is not a strategy

Luck is not a factor

Fear is not an option

By the way I WON!!!!!