Forum

Author Topic: Orthomosaik with cylindrial projection  (Read 3516 times)

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Orthomosaik with cylindrial projection
« on: January 18, 2018, 02:53:07 PM »
Hi,

i want to unwrap a surface with the function orthomosaic with cylindrial projection (See attachment).

My axis Points are Abwicklung 1 and Abwicklung 2, my Point on the surface (origin Point) is Abwicklung 3.

It seems the unwrapped orthomosaic is projected on the whole cylinder !?

Is there a Workaround for my Problem?

Thanks

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 12939
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #1 on: January 18, 2018, 02:56:27 PM »
Hello Dieter,

Can you please also post the resulting orthomosaic overview? Do you mean that there's a lot of unused space in the final image?
Best regards,
Alexey Pasumansky,
Agisoft LLC

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #2 on: January 18, 2018, 03:16:20 PM »
The Result from Agisoft is Agisoft.jpg, the correct result is correct.jpg.

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 12939
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #3 on: January 18, 2018, 03:54:13 PM »
Hello Dieter,

We'll try to reproduce the issue.

Can you please specify, if you have used "Interior Projection" option? It looks like the provided images are mirrored compared to each other.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #4 on: January 18, 2018, 04:35:09 PM »
Oh yes, i'am sorry, the correct.jpg is mirrored, my mistake.

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #5 on: January 21, 2018, 02:19:11 PM »
But the Problem still exists. The dimensions of the orthomosaik from agisoft are wrong. It seems the unwrapped Surface is scaled over the whole Surface of the cylinder !?

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #6 on: January 24, 2018, 10:23:29 AM »
Hello Dieter,

We'll try to reproduce the issue.

Hi, are there any news about the issue?


Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 12939
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #7 on: January 24, 2018, 06:17:32 PM »
Hello Dieter,

It looks like the radius of the cylinder for the marker-based option hasn't been properly estimated in 1.4.0 and was using the bounding box instead. It will be fixed in the 1.4.1 update.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #8 on: January 24, 2018, 07:36:08 PM »
Thank you very much :)

Can you give me an overview and working methods of non-marker-based projections? There are no explanations ....

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 12939
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #9 on: January 26, 2018, 06:52:44 PM »
Hello Dieter,

Here's the paragraph related to the cylindrical projection definition that we are planning to include in the Manual, if you have any comments or additional clarifications are required, please, let me know:

Quote
Cylindrical - allows to project orthomosaic on a cylindrical surface. It helps to avoid severe distortions while projecting cylindrical objects, like tubes, round towers, tunnels, etc.

To project 3D points on a cylindrical surface one needs to: 1) define the cylinder, i.e. define its axis and its radius; 2) drop a perpendicular from the 3D point to the axis of the cylinder - the point of intersection of the perpendicular and the cylindrycal surface is the projection of the 3D point in question; 3) agree on how to define x and y coordinates of a point on the cylinder. For the purpose of orthomosaic and DEM generation in cylindrical projection PhotoScan defines x and y coordinates of a point on the cylinder in the following way: x - along the curve in the zero-plane, y - along the zero-element of the cylindric surface (zero-line), where zero-plane and zero-line are to be defined.

PhotoScan offers four methods to perform projecting on cylindrical surface. They differ in how the four core elements - cylinder axis and radius, zero-plane and zero-line - are defined:

1. Current Region. The cylinder is inscribed in the Bounding box: the axis goes through the cross sign on the bottom side of the Bounding box perpendicular to the bottom plane; the radius is defined as one half of the shorter side of the rectangle in the bottom of the Bounding box. Zero-plane goes through the center of the Bounding box perpendicular to the axis; zero-line belongs to the Bounding box side which is opposite to the side with the vertical marks.

2. Current View. The axis is set as the line from the viewpoint to the center of rotation for the model. Radius is defined as one half of the shortest of all the edges of the Bounding box. Zero-plane goes through the center of rotation for the model perpendicular to the axis; zero-line goes through the highest point (in monitor-related coordinate system) of the curve in the zero-plane.

3. Markers. At least three marker are required. The first pair sets the axis. The third marker defines zero-point, i.e. defines zero-plane and zero-line, on condition that radius is the distance from the third marker to the axis.

4. X/Y/Z. The axis is the line parallel to the corresponding Cartesian axis - X/Y/Z, going through the center of the Bounding box. Radius (r) is defined as one half of the shortest edge of the Bounding box. Zero-plane goes through the center of the Bounding box perpendicular to the axis; zero-line is the line opposite to the cut line. The cut line definition for each of the three possible options is illustrated on the Figures below.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #10 on: January 26, 2018, 07:13:51 PM »
Wow, i`m impressed :)

I'll give it a try this weekend.

Thank you.

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #11 on: February 05, 2018, 02:06:03 PM »
When i use "Interior Projection" option, the picture on the screen looks right, but after saving the orthomosaik to file it is mirrored again.....

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 12939
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #12 on: February 05, 2018, 07:48:11 PM »
Hello Dieter,

Thanks for reporting, this problem will be also fixed in 1.4.1.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #13 on: April 12, 2018, 07:18:58 PM »
Works good now!!

Thank you

Dieter

  • Full Member
  • ***
  • Posts: 111
    • View Profile
Re: Orthomosaik with cylindrial projection
« Reply #14 on: June 22, 2018, 12:46:05 PM »
The cylindrical unwrapping works great, thanks for that.

How about a new challenge?

In addition to the cylinder we need a cone, which we can unwrap. This happens again and again and we lack a possibility for it.


The attached graphic shows the variations ....


Thank you in advance
Dieter