Assigning DPI value to saved images/renders and the benefits
Blenders native 72dpi can get really limited as the renders will come out pixelated even at 1920x1080 resolution. This fact forces users to bump up resolutions a lot and then use software like Photoshop to try and fix the issue.
At work i needed to render out some kitchen doors for a catalog and the work load was spread out to a coworker who uses 3ds Max. While we both had similar lighting and good image quality (mosly because we agreed to make 1 HDRI image for the lighting set up and we used materials we made to be extremely similar), I found myself falling behind because as he was rendering at exactly the resolution needed for the catalog and exporting the images at 300 dpi, while I was rendering at 3 times the resolution in order to get to the same print ready DPI needed.
As another example, i tryed to export a procedural material as image bitmaps for a coworker who was falling behind on time. Because the fixed 72 dpi and the material having fine details, the only resolution I could get that had the materials rendering properly was 12000x12000, having a dpi setting for baking materials would help a lot, as that can be used to bake normal maps (for example) at 1024x1024 and keeping that detail by using a 300-500dpi setting. (even though I understand that baking an texture map at 300dpi will take significantly longer than at 72dpi, but i believe that the quality it brings is totally worth it)
The point I'm trying to get across is that a DPI setting for exporting images and one for texture baking will cut our rendering times (and time spent resizing images in software like Photoshop) by a lot, and improve the quality of materials exported out of blender.
On a side note, discussing this topic with 2 coworkers (one using 3Ds Max and the other using Cinema 4D) we came to the conclusion that a DPI setting brings a LOT of value in both time, and quality and it is one draw back when it comes to switching from 3Ds Max to Blender.
10 Comments
This problem has been around for over 16 years, and now you can use it github.com/AIGODLIKE/dpi_tool
Sorry, but You just don't understand what DPI means.
DPI - Dots per inch is a value that let You calculate resolution in pixels if You know physical dimentions and desired image quality.
Simplyfing: image resolution in pixels = dimensions * DPI
Example:
A4 * 300DPI = 2480×3508 pixels
A4 * 72DPI = 595×842 pixels
Perhaps it was a translation issue that caused some confusion in our understanding, but in the end, I developed this for Blender
github.com/AIGODLIKE/dpi_tool
extensions.blender.org/approval-queue/dpi-tool/
Blender isn't really designed to be a Print-Ready Medium producer. That being said, there are plenty of free programs around that can update the image meta data to change the target DPI. (Gimp comes to mind.. Irfan can probably also do it) There's an interesting conversation on BlenderArtists
If you still want to pursue the idea, try to track down the developer of the Render_To_Print Addon and see if they are ready to release a Blender 2.80 version.
Perhaps it was a translation issue that caused some confusion in our understanding, but in the end, I developed this for Blender
github.com/AIGODLIKE/dpi_tool
extensions.blender.org/approval-queue/dpi-tool/
dpi = how much pixels for 1 inch ..
So if you say i've got a 1920x1080 pixels image, whatever your dpi are you end up with 1920x1080 pixels. There is no correlation. In order to improve "quality" you need more pixels.
Pixels doesn't have fixed physical size, in facts the size depends on the medium. In a 72 dpi device, pixel size is 1/72 inch. In variable dpi mediums like printers, setting dpi define the size of your image, but pixels count remains constant.
Perhaps it was a translation issue that caused some confusion in our understanding, but in the end, I developed this for Blender
github.com/AIGODLIKE/dpi_tool
extensions.blender.org/approval-queue/dpi-tool/
I think you mix things. native 72 dpi, is only for the interface. If you feel 1920*1080 render is too pixelated, you have to increase the resolution, the dpi doesn't play in any case about this issue. If you need to know how much the resolution should be, you have to multiply the print size by the quality you wish and fill blender width and height with the result. Example : you want to print 10 inch wide image, you wish a 300 dpi quality (standard quality for this size), your render will be 3000 pixels large.
* @dddjef * The interface resolution is indeed 72 dpi, but so is the render output, looking at any image rendered in blender you can see that the Horizontal an Vertical resolution is 72dpi. All other 3D software have a setting to adjust it and it can come in extremely handy in a lot of situations.
I understand what you are saying, but is just rendering at a higher resolution, thus taking more time, the best option we have? Same goes with baking. If i need to bake out a normal map from a extremely high resolution model (say a photo-scan) do we really need to set a high resolution image in order to not get artifacts in the bake?
Perhaps it was a translation issue that caused some confusion in our understanding, but in the end, I developed this for Blender
github.com/AIGODLIKE/dpi_tool
extensions.blender.org/approval-queue/dpi-tool/