speed of depth map I thought it was faster than point cloud

[Steve003]

Hi,
Metashape 1.5.3
seeing the advert of it being finer detail and faster, 9hrs v 19hr on 730 images with use of depth map,

small wheel and axle of trolley.

Photoscan 1.4.5
create dense point cloud ultrahigh setting aggressive 6.5 hrs
mesh high setting 1 hr

Metashape 1.5.3
create mesh use depth map quality ultrahigh  reprocessing done 2hrs, estimating surface 4 hrs .  so 6hrs  :(when 1.4.5 using cloud 1 hr  . 6hrs when need pc for other intensive cad work is an issue.

Whilst I will be happy if its a higher quality the 600% more time needed on meshing doesnt tally with the 9hrs  vs 19 hrs on 730 images, I only have 90 images. cuda enabled, 32Gb ddr vengeance pro ram, Intel Core i7 4790 3.6Ghz dual core:-

What settings should I be using to get a faster result than in photoscan 1.4.5 ?

I see also reuse depth in both point cloud and mesh options but unsure of if we tick that or not.

I also see mention of use sparse cloud then select sparse cloud in mesh but so far found sparse to be rough quality so not sure if I will get a super fine detail mesh from such.

Should metashape be starting off with users selecting sparse and moderate on a new project ?

Steve

[Alexey Pasumansky]

Hello Steve,

If you can share the dataset (source images and the project with the alignment results), we could try to reproduce the similar behavior on our side and check, what could be optimized.
Mild filtering is default for the depth maps generation in Metashape and it is the recommended option for the new mesh generation source.
Using the sparse cloud as a source for the mesh generation would give you only rough model for some quick overview. Although you can run "Refine Mesh" operation to improve the details of such model, but recommended workflow suggests depth maps to be generated (either for the dense cloud ro directly for mesh) in order to get detailed processing result.


As for the general information, hope the following comments would be helpful:

old mesh (from the dense cloud) generation operation includes the following steps: Build Depth Maps (Time1), Build Dense Cloud (Time2), Build Mesh (Time3).
new mesh (from the depth maps) includes the following: Build Depth Maps (Time1), Build Mesh (Time4).

When you are re-using the depth, it means that you can skip the first step in both operations. Time1 would be identical in both approaches, if the same application version is used (mesh from the dense cloud is available in Metashape 1.5). But compare the complete processing time for two meshes you should consider also the time spent on the dense cloud reconstruction, so Time2+Time3 vs. Time4.

[Steve003]

Hi Alexei, sending files and project via wetransfer.

Mild filtering is default for the depth maps generation in Metashape and it is the recommended option for the new mesh generation source.

use of :-
sparse cloud
arbitrary
medium

 in dense point cloud first use, saw mesh create a mess with half the wheel missing at inside face.

but recommended workflow suggests depth maps to be generated (either for the dense cloud ro directly for mesh) in order to get detailed processing result.

How does one choose to generate depth maps, I dont see an option in align photos or next stage dense point cloud to tell it to make depth maps. Nothing in manual pdf either.

old mesh (from the dense cloud) generation operation includes the following steps: Build Depth Maps (Time1), Build Dense Cloud (Time2), Build Mesh (Time3).
new mesh (from the depth maps) includes the following: Build Depth Maps (Time1), Build Mesh (Time4).

again same question these steps refer to choosing to make depth map but how ?

Not sure what you mean by Time 1 etc ?

Steve

[Alexey Pasumansky]

Hello Steve,

Depth maps will be generated if any of the following operations are started from the Workflow menu:
1) Build Dense Cloud, depth maps quality is defined in the corresponding field ("Quality");
2) Build Mesh (only if both Arbitrary surface type and Depth Maps source options are selected), depth maps quality is defined in the corresponding field ("Quality");
3) Build Tiled Model (only if the Depth Maps source option is selected), depth maps quality is defined in the corresponding field ("Quality").
Each of these operations will generate the depth maps as a first sub-step of the processing.

Sparse cloud selected as a source for the mesh generation is only reasonable if you need to get a rough overview of the reconstruction in short time.

I've downloaded the provided data and will start the processing shortly.

[Steve003]

Hi Alexey,

1) Build Dense Cloud, depth maps quality is defined in the corresponding field ("Quality");

As there are a choice of quality: ultra high, high, medium, low and lowest.
I would like to think that as depth map is the 'new toy' we can play with for better results, ultrahigh will make an ultrahigh depth map and make sure the mesh is great,
ultrahigh dense point cloud (lets call dense point cloud dpc) took 6.5 hours  in photoscan 1.4.5 
mesh ultrahigh using 'high' dpc took 6hrs in Metashape 

I am frightened to create ultrahigh depth map in dpc 6.5hr then retain its quality with ultrahigh in mesh, a further 6 hr process ! 

or its ultrahigh in dpc and high in mesh 7hrs or high in dpc and ultrahigh in mesh, also 7hrs.

but the former one is taking ultrahigh depth map and despoiling it down to 'high'.

2) Build Mesh (only if both Arbitrary surface type and Depth Maps source options are selected),

We need to alter ‘and’ to ‘or’ because….
In build mesh, which requires that a dense point cloud has been created before being chose, there are two options
a) source: Dense cloud and this then shows arbitrary3D  in the Surface type box
b) source: depth map in which case surface type and the choice of arbitrary is denied, being ‘greyed out’
so depth map and arbitrary are not together possible.

3) Build Tiled Model (only if the Depth Maps source option is selected), depth maps quality is defined in the corresponding field ("Quality").

I cant find a setting to build a tiled model and am unfamiliar with what that is used for.

Sparse cloud selected as a source for the mesh generation is only reasonable if you need to get a rough overview of the reconstruction in short time.

I have tried sparse a couple of times but the result from mesh choosing source sparse sees a model so rough and incomplete its totally unusable for editing the background from, building a mesh based on sparse I just can’t see a use for myself.

regards

Steve

[Alexey Pasumansky]

Hello Steve,

Hope you are not confusing the things up.

1) Build Mesh -> Source Data = Depth maps -> ONLY available for Arbitrary surface type.

2) Build Mesh -> Source Data = Dense cloud - is STILL available in Metashape. This meshing method has not changed since PhotoScan 1.4.

3) "Visibility consistent experimental" mesh generation from PhotoScan 1.4 is no longer available in Metashape 1.5. Even though both meshing options use Depth Maps as a source, the algorithms behind them are considerably different.

4) "Quality" parameter in Build Dense Cloud and in Build Mesh (when Depth Maps source is selected) has SAME meaning - it is the quality of the depth maps to be reconstructed as a first phase of building the dense cloud and mesh. In the older PhotoScan versions, the depth maps have still been generated during the dense cloud reconstruction.

5) Face Count value presets (High, Medium and Low) have NOTHING to do with the depth maps Quality settings, they (face count presets) only define the target polygon count in the output model.

[Steve003]

Hi,
1 and 2...yes understand that as , if depth map uses arbitray 3D then thats why its denied as a choice, its greyed out.
when you had said

2) Build Mesh (only if both Arbitrary surface type and Depth Maps source options are selected),

it was  the fact that one cannot select depth map AND arbitrary3D. it should be depth map (arbitray greyed out)  OR densepoint&arbitrary 3D.

"Quality" parameter in Build Dense Cloud and in Build Mesh (when Depth Maps source is selected) has SAME meaning - it is the quality of the depth maps

As such, I need to know though , if Depth map is made with UltraHigh densePointCloud, so we have UltraHigh quality depth maps, does choosing High in mesh mode reduce the depth maps from ultra high to high lessening their quality ?

should we also then use ultra high in mesh mode to retain the quality of the ultrahigh depth maps created in densePointCloud stage ?

I am running ultra high mesh on ultrahigh densepointcloud in photoscan and big problems with time its taking ,see posted thread.
https://www.agisoft.com/forum/index.php?topic=11090.0

Steve

[Alexey Pasumansky]

Hello Steve,

For depth maps source there's the only option - Arbitrary. And there's no other choice, so it is not possible to select Height Field mode for this source option. Arbitrary is always selected for Depth Maps.

If you have Ultra High depth maps in the project and are selecting any other quality for Depth Maps based mesh reconstruction - the new set of the depth maps will be generated from scratch. The only possibility to re-use the available depth maps is to select the same quality option and check on "reuse depth" option (in Build Mesh or Build Dense Cloud dialog).