[Addon Revival] Render to Print now with option for printing to scale.

(faerietree) #1


What it does?
The render2print addon has always allowed to set the render size to print formats like A4, A3, … Now reC’s + friend’s + mine work extended it to allow to print out to scale (e.g. 1:50).

Why use it?
Printing out rendered (cycles, freestyle or OpenGL viewport) images of your models. Combined with cross section plane approach or addon (both ways exist), this allows to create manufacturing or assembly drawings.

Also useful with caliper or measurement addons. Not sure if Grease Pencil->Ruler can be openGL viewport rendered.
Margins allow to relocate the scale ratio text:

It is no new addon, but extends the old one. (Not losing the overview over all those great (all but mine) addons is difficult enough already.) Remember the old functionality is unchanged, we merely extended this great addon (version 0.2).

Important note when setting up the printer!
There is a DPI (dots per inch) setting that you choose in the render to print panel . Remember this value! Don’t forget it! Keep in mind that this setting (dpi) has to be exactly the same in all programs you use your tool chain (blender + image manipulation program for printing [+ printer]).

How to use it?

  • Create your artistic scene or engineering model.
  • Setup a camera that looks as you want.
  • Do some test renders to get the materials set up to your desire.
  • Enable the script in the Addons settings CTRL+ALT+U. Search for “render to print”. Enable the most recent version.
  • Go to the render tab and scroll to the very bottom. You’ll find the Render to print settings there.
  • Choose your preset format (A3, B5, …) or set a custom one.
  • Enable the to scale option if you want a certain scale ratio for the print out.
  • Choose a scale factor (scale ratio) that you like and that fits the objects you’ d like to print on within the camera size after executing the render2print main operator (see next step).
  • Apply your settings to the render settings and camera by executing “Apply render2print settings”.
  • Check the camera (best change into the camera view before executing the main operator as described above).
  • Check if the text representation of the scale ratio (e.g. 1:10, …) has been added and is visible from the camera.
  • Finally render the scene and save it out to an image if you like (F3).
  • If you want to print it, then you’ll need to remember the DPI (dots per inch) settings in the Render to print settings in the render tab of the properties panel.
  • Open the just saved image in another program where you can set the DPI (like GIMP).
  • Check the print settings and set the correct DPI of your image.
  • Open printing menu (CTRL+P).
  • (optional) Check for the DPI if the printer has a setting for it. Not sure if it has. GIMP somewhat overwrites this setting or at least hands it over to the printer on its own. But you never know.
  • Print.
  • Check the result on paper. And tell us if something is at odds.

Video showing a quick testing walkthrough:

Sorry for the really weird quality, I recorded 800x640, cropped it to 800x440 and had set a rather way too high than too small bitrate of 6000 … turns out the format messed it up. MPEG output always results in this low quality while AVI doesn’t.


  • Only orthographic camera mode is enabled so far. (field of view and location have to be taken into account for other camera types, and this has low priority currently unless it’s really needed)

The addon switches the active camera to orthographic mode automatically if required.

Archipack 1.3.8 - 18.04.2018
(Nanomanpro) #2

Great addon… MM->Pixel would be even more useful…

(ejnaren) #3

Fantastic! I have had this functionality on my wish list for Blender for years! Thank you!

(reC) #4

doesn’t work for me

i tried to print on standard a4 a 1360 cm square on 1 to 100 scale in cm. on paper there should be a 13,6 cm square but it is only 9 cm instead.

has anyone produced something useful ?

(faerietree) #5

Okay, I came up with the fix. Most was correct besides that I mixed up the longest side what had fatal consequences for portrait mode.

Did anyone try landscape mode? This should have worked right away.

I will update the first post.

(reC) #6

hi there and thank you for taking interest in my silly way of explaining my friends work.

for a while I thought that this was just a lost cause because no one responded or gave any feedback but now I see that someone has.

I will test this out to see if it works and will give feedback here !

(faerietree) #7

Hey I have to thank you. Not the other way round. You can image how I was stunned to find a link to our great ‘blenderartists’ when I was searching google for related groundwork for printing to scale! It really was a big surprise … I looked for physics and maths sites and my best luck was blenderartists instead. You’re amazing, colleagues. :eyebrowlift2:

I should be punished for not engaging a printer to test. Okay I had printer connection issues in my UNIX development system but perhaps I should have put more time into it… Probably that nasty 1:100 , 1:50 visualization took so much time that I omitted the printout tests… omg … at that time I must have been drunk and thought - hey, what shall go wrong, if it’s shown correctly in blender then surely it will print out correctly too if you use the same DPI settings. Interesting too that it was only showing up correctly for landscape format and I did not even realize that. :eek:

(reC) #8

hi, yes blenderartists is a great place to find weird ideas.

I have tested and now it works … at least for standard a4 it does.

you needn’t waste print paper to make tests. all you need is to verify the correct ratios. bellow are some screen snips to how I do mine in blender.

just add a plane mesh to the same origin you added the camera. give the plane mesh the same size, ratio and orientation of the camera. next add a plane mesh from the same origin point in stead of printing.

let me know if you don’t understand something

(faerietree) #9

Yes, dude, that’s exactly how I tested it. Nice to see you do the same. Thanks for explanation, so addon users can test themselves now too.

Wait, you have some interesting additional helper lines activated, isn’t it? Interesting …

Now you see your effort was very useful and led to simplifying and lessen our virtual burdens. Your thread has been ignored for a long time, has been closed even … and finally led to our goal anyway. Brilliant. I wonder why all cultures and religions work in harmony on blender(artists) - but not in the real world. There a worldwide union is more unrealistic than being sent to the moon on a mission to create the first blender headquarters in mare ad unitatem orbis terrarum and to paint both the chinese and the american flag in the colours of all nations/ethnics of earth. Can we call this unrealistic? :eek:

(reC) #10

the doted helper lines are a function of the camera. you can find it under the \display\composition guides\

it helps with the composition

has no one else played with this yet ?

(faerietree) #11

Thanks. Will recheck soon. This Addon is next after Selection2Bill Of Materials Addon for my newest (Metal) 3D Printer and Mill Design which is under evaluation.

Should we create a script that downloads and keeps addons useful for engineering up to date? Probably yes at some point. Not sure when I’ve time for that though. BlenderCAM script is already huge simplification… and it’s working with newest Release candidate and should work with any blender version as correct python is resolved automatically. Sorry for offtopic. Just too enthusiastic that it finally works. Almost had given up.

(faerietree) #12

Sorry for the delay, had some open hardware tech to drive forward. With the render2print addon to scale we need to experiment a bit because when taking over maintenance from epic scripters Marco Crippa and Dealga McArdle, I not yet used Git! (a huge mistake!)

… so as you see in the (really weird quality, bitrate?) video now we have 3 versions … and modification date and time are equal, because I run some automatic script operation.
Long speech short, while Landscape version works, we’ll have to experiment a bit or refix the Portrait mode.

Btw. that’s a reason why I coded the addons gather and link script … single source principle.

(faerietree) #13


Added link to public Git repository.
Fixed Portrait Mode.

Have fun.

(RickyBlender) #14

need some step by step instructions on how to properly use this script.

1 - when can you use this script
do you need to have a printer connected or not ?

2 - you say add a plane in post 9 then a camera at same location ?
do you mean to add a plane a X=Y = Z 0
but what size of paper do you need is it 2X 2 BU ?

then add a camera at X = Y = 0 at a higher value of Z = 10 or 20 above the center of the plane ?
you also say to set the camera same scale then the plane
can you elaborate a little on this!

3 - where does the new panel appear in which window ?

  is it the UI window or the printer propertie window ?


(faerietree) #15

No printer required for testing. The render2print updates the render dimensions and camera focal length/zoom such that your rendered image can be printed out on a certain format and to scale. This means it’s the artist’s responsibility to make sure the objects you like to print really appear on the render. If not, then you must choose a smaller scale factor (e.g. 1:50 instead of 1:10).

Pay attention to the DPI setting, it must be equal in all programs: blender -> saving render as image (F3) -> printing the image. The DPI tells how big a pixel in real size is or the other way round ‘dots per inch’.

Oh, what you described is for testing the script only (this is what I demonstrate in the video, the testing procedure).
If you have a scene, then just as usual set up the camera where you think it looks good. (Though for engineering purposes setting it on the z-axis makes sense but as it is useful for artists printing their renders too, this is no requirement.)

In settings panel to the right -> render tab -> very bottom.

Will try to create a better video, probably the time remap screwed it.

Need some input too as I’m working on creating a textual representation for the scale ratio.
q1- I currently locate it in the right bottom corner of the camera. Hope that’s fine? You can always flip it by flipping the sign of the delta/local location of the text object.

q2- Is MM->Pixel really required? Can’t we just use CM for that? If it’s useful, then I’ll add this option of course.

(RickyBlender) #16

not certain what unit to use
in our country for engineering Metric drawings we always use mm not cm!

got a few suggestions

I made a Xcell file to evaluate the net and real dimensions for different drawings
may be it can be added to your script!


(faerietree) #17

A scale ratio text representation now is created automatically too. It’s located in the top right corner. An important missing functionality.
Note the scale ratio is stored per camera. Move the camera and it will just continue to work! Should work in all camera rotations, tell me if not.

Thanks, sounds interesting. How are the specifications, what exactly does it validate? Are there inputs needed? A requirements file? Or are this just on the fly calculations that work with the info we already have (in the addon print settings in the render tab)?

not certain what unit to use
in our country for engineering Metric drawings we always us mm not cm!

True, in my country it’s the same. I just thought entering mm into the cm fields is just moving the comma by one. Yet if it’s useful then we can add it. Let’s wait for some more opinions.

(reC) #18

A good script when coupled with svg export. It still can’t be compared to sketchup + layout flexibility. But it’s a great start in that direction.

An option is to convert everything on the fly to mm. Here is a good online calculator for pixel size http://www.sizecalculator.co.uk/

(RickyBlender) #19

let me give an example
let say a letter size 8 1/2 X 11 inches

this is the total area and it does not mean you can use all this area for drawing!

there is the margin all around the drawing which is not normally use for drawing
sometime some drawings number might be added in the margin!

ok a bit technical here

so I did that xcell program to show what was the net area available for drawing
but also function of the scale of the drawing what is the maximum size of objects in the drawing
this is needed to know what max object size can be put on a given sheet size function of the scale used

but this would not need to be shown in the panel but could be printed on the console
mind you could also be added on the panel!

did u update the GIT version
so I can test it ?

i’m working on a small script to show how to add a plane with proper dim
to show sheet size with margins.
may take a few days before I complete this

thanks for feedback

(reC) #20

Just had a go at the new svg export feature combined with this addon.

Opened in inkscape(has 90 DPI internal setting - must use this value in render to print to get accurate results)The internal precision is allways off by almost 1 mm at 1:10 scale with any format. On paper Should be 100mm instead got 100,862

Tried both standard A4 and B0. It seems that Blenders camera ortho scale setting is to blame here. If it had one or two more decimals of precision it would be perfect(maybe)

The good news is that it doesn’t vary from small size to large size. It’s just a little off.