Introducing scale bar in rendered file

[Ingsayyad]

I want to know scale of my rendered file just like orthoimage. How can introduce a user-defined scale bar in my rendered file or how can I know size of pixel/cm etc. in render file.

[daniel]

The only scale by default is the one that appear in the bottom right part of the 3D view (only in orthographic mode).

But you can use the following trick: create a fake cloud with two points having the extreme (min and max) horizontal coordinates of your real cloud.

Then with these 2 points you can:
- create a polyline (with the 'Point List Picking' tool), change it's name to the right dimension and enable the 'Show 3D name' properties of the polyline
- or create a 'Distance' label (with the Point Picking Tool). You can then collapse the label to a shorter version (by right clicking on it) with only the distance.

In both cases this will give you a kind of 2D scale bar that you can displace anywhere you want with the Translate/Rotate tool (if it's a polyline, you can displace it directly, and if it's a distance label, simply move the associated cloud).

Here's an example with both versions:

cc_fake_scale_bars.jpg (138.67 KiB) Viewed 16499 times

Personally I prefer the polyline version because it's cleaner and you can customize the width and change its color afterwards.

P.S.: instead of creating a fake cloud you could also simply clone your original cloud, pick the extreme points and eventually hide the cloned version at the end of the process by disabling the 'Visible' checkbox so as to keep the label visible (but it might be harder to get a nice horizontal scale).

[cdordoni]

That is a good idea, have not tried the polyline tool myself.

Would the polyline be saved in the .bin file so it could be used again?

[daniel]

Indeed. You can save about anything in a BIN file (and of course you can save the polyline in a separate BIN file as well).

[Ingsayyad]

I did also with fake cloud and importing as text. This helped me to place scale bar virtually at any place in window. My other question was/is about orthoimage. It is orthographic projection. If I can selected starting and end point in window and make an image, I can use it like orthoimage.
This means a lot, i.e., CC can be used to make orthoimages.
Trick I use is that:

• make fake cloud with boundaries (user-defined).
  render the image with scale.
  Go to 3rd party software and cut image by using these boundary points/lines.
  Now I can paste it in Autocad with real scale.

[daniel]

There's a special method that could help you:
http://www.cloudcompare.org/doc/wiki/in ... djust_zoom

This was created to created prints at real scale (or a percentage of it). It will let you specify the pixel size in real units.

[Ingsayyad]

Thanks for this nice tip.

I can't figure out how can I render file on exact scale.

Here are details:
1:Adjust Zoom
window 3D view: 1.95
pixel-size=.03 units /1 pixel

2:rendered to file @5 times zoom
3:Imported into AutoCad with scale 1
4: the scale bar showed 10 m in image has length 17+ m, therefore I have to scale the image again and the calculated scale in AutoCad =0.576

Can you guide me what should I do (play with settings), so that I don't have to scale my image in AutoCad and the quality is also good.

[daniel]

When you open the image in an external tool (paint, etc.) can you measure the width of the scale bar in pixels? You should (in theory) find the pixel size you have input. I just tested this with the 2.6.2 version and it works fine on my side.

Beware also that:

• this only works in orthographic projection mode
• you have to take the scale bar line width into account (in practical you should ignore one of the vertical sgements)
• there was a bug in the 2.6.1 version (and earlier) when rendering the scale bar with a zoom greater than 1

[Ingsayyad]

I got it. Do you see any possibility to introduce limit in rendered file. By default it renders the whole 3D window..

[minx,miny]-----> [maxx,maxy]↓
x,y are current units of point cloud.

[daniel]

Not in the way it is implemented (we use OpenGL to grab the whole display).

But of course you resize the screen so as to get the right area (it shouldn't change the zoom / pixel size).