Forum

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - simiyutin

Pages: [1]
1
General / Re: Automated mission planning
« on: March 03, 2021, 09:01:02 PM »
We have tested it in RTK mode with DJI base D-RTK 2 station and it worked well. We have not tried NTRIP connection but app supports it and it seems that this feature works too.

Just in case, you do not need precise absolute positioning in the world just for mission planning feature to gain from RTK. All you need is ability to exactly follow routes built from initial overhead flight. If both initial and second flights are captured with the same configuration of base station you are fine even there is a constant shift to absolute positioning. This is convenient property when using mobile base station as you don't need to care too much about measuring precise base station coordinates or rely on NTRIP signal strength.

2
General / Re: Automated mission planning
« on: March 02, 2021, 12:58:40 PM »
@3DWinter @MaciekK

For Phantom 4 RTK it is recommended to use DJI Pilot for Android (tested, works fine). iOS version seems to support only Mavic Enterprise according to docs. For non-RTK drones Litchi can also be used, however DJI Pilot KML format supports multi-photo waypoints better than Litchi KML. DJI GS Pro was lacking ability to import KML files with specified gimbal rotation at least in the past.

3
If your drone supports RTK then positioning and orientations are very precise, it is possible to set capture distance as low as 1 meter from the surface and safety distance as low as 0.5 (in case of well-reconstructed obstacles or exhaustively specified by manual tools), but you still have to carefully follow the drone in case of GPS shadowing in concave regions.

When only GPS is available positioning is prone to errors up to several meters and it is recommended to set safety and capture distances at 15 meters or more.

For some examples you can check out model built from 3500 flight planned photos and screencapture of another model with flight plan overlay



4
Hey!


You may try using DJI Pilot app instead if Litchi. It officially supports only a small fraction of drones but quietly works with a larger subset (e.g. regular mavic). You need to export plan in DJI Pilot KML format in this case.

Also you can try using Android version of Litchi - it seemed to work fine in the past

5
General / Re: Best Method for Data Collection, Powerline Detection
« on: February 24, 2021, 09:44:36 PM »
Hey!


The best method to collect images is multiple oblique linear flights (see attached image). 2 flights are required minimum, 4 flights are recommended as less noise and unreconstructed spans will occur.



6
Unity engine delighting is similar to "Remove shading" option in Delighter and Metashape. Difference is that Delighter uses more sophisticated algorithm and should handle cases of mismatched geometry and texture better plus generating less artifacts. On the other hand it currently lacks GPU acceleration and is noticeably slower

Substance alchemist uses some machine learning implementation while Delighter uses classic approach. I haven't not compared them side by side, and can't provide much useful information, but showcase examples look promising. One possible issue with application of Alchemist to 3D model textures is that treating texture atlas as a picture and not a mapping of 3D surface may lead to strong artifacts on chart seams


7
1) Most parts of algorithm are parallelized. Some intermediate computations left single threaded but should take only fraction of total processing time. If this is not the case you could share sample dataset if it's alright
2) Delighter currently does not offer such functionality, however it uses the same AO baking algorithm as Metashape and AO maps export is available from there

8
General / Re: Reduce overlap feature
« on: October 27, 2020, 03:44:43 PM »
Hello everyone!

In Metashape 1.7 pre-release Reduce overlap feature was updated and now uses more straightforward parameter: number of cameras per surface point. Now algorithm tries to select minimal set of cameras such that each point of rough model is observed from at least N significantly different angles(multiple cameras from single direction count as one) where N is specified by user. The new version is also approximately 100 times faster!

Previous algorithm used similar logic but with more complex formulation and weighting and was not as interpretable as the new one.

9
General / Re: Automated mission planning
« on: October 27, 2020, 02:36:15 PM »
Hey!

In Metashape 1.7 pre-release a new Prefer horizontal movement checkbox appeared, which seems to be an option you need. You can also check out updated Mission planning tutorial

10
Hi!


"DJI Pilot" export format is intended for use with correspondent app only. From official DJI documentation Mavic 2 Pro is currently not supported (only Mavic Enterprise), but some posts on DJI-related forums say that it quietly works with some other drones including Mavic 2 Pro.


When using Litchi you need to select "Google Earth" KML export format and check both "Threat views as Waypoints" and "Add Take Photo Action" ticks when importing KML file using Litchi Mission Hub (https://flylitchi.com/hub)

11
General / Re: Automated mission planning
« on: September 08, 2020, 12:54:43 PM »
Hello,


Currently vertical zigzags are the only available option but alternative modes may appear in upcoming updates

12
> Is there any reason why full functionality of Deligter (including removing cast shadows and painting on geometry) is not defaultly present right in Metashape itself too

Separate app is simpler to deliver as a free tool. Plus, brush functionality needs some specific user interface so it is easier and cleaner to be implemented in a separate window

> do i understand it correctly that Delighter actually computes its own AO map on the fly and uses it for deligting...?

Yes, De-Lighter uses in-house AO baking algorithm introduced in Metashape 1.6

13
> 1) What is this new feature "Remove Shading"?

"Remove Shading" feature is basically the same as "Remove Lighting" from Metashape with minor tweaks. It removes shadows using local orientation of the surface (consider a lit cube with each face having different brightness corresponding to face normal and direction to light source).
Cast shadows are often not supported by surface normal (e.g. flat ground with cast shadow from object not represented in mesh at all) therefore they become invisible to "Remove Shading".

"Remove Cast Shadows" ignores geometry and leverages user input to classify texture points as lit and shadowed based on texture color.

Usually if there are hard cast shadows on model texture it is reasonable to run "Remove Cast Shadows" first and optionally "Remove Shading" later to make brightness more uniform. If only shading and AO are present it's better to use "Remove Shading" instead.


> 3) This "RemoveShading" feature doesnt requite you to draw on the model, right?

Drawing is not required but you can specify mask using cyan color brush. For example, considering a typical "rock on ground" scene, using mask to separate ground from the rock will prevent color leaks between them.



> 2) The version of Delighter in the tutorial didnt yet have this feature? (or did you take the original process and splitted it into two separate functions?)

Yes, the tutorial is a bit outdated and doesn't cover new functionality.

Pages: [1]