Messages

166

General / Re: Getting section cuts from the models

« on: November 02, 2013, 01:48:51 AM »

I use Rhino to create digital models of boats based on point clouds and meshes from PhotoScan. I import the mesh and/point cloud into a Rhino model and save it as a Rhino .3dm file. I do the Rhino work in a separate .3dm file. I use "Worksession" in rhino to "attach" the .3dm files with the needed meshes/point clouds so they can be used as references without adding to the size of the file with the modeling data.

Sufficient memory is needed so that Rhino does not start swapping data between memory and disk. How much memory depends on the number and size of the meshes/point clouds. I usually use meshes rather than point clouds.

167

General / Re: Workstation question

« on: November 01, 2013, 06:46:33 PM »

The GPU is only used for building the dense point cloud. CPU only is used for aligning, building mesh, building texture, etc.

I have a one year old desktop with an Intel i7 3770 CPU and an AMD Radeon HD 7770 graphics card. My experience is very similar to hengefjes. The GPU contributes significantly during building the dense point cloud. Cards similar to the card in my desktop currently sell in the US for slightly over $100.

168

General / Re: Is the AMD 7970 graphics card still the best option for PhotoScan?

« on: October 30, 2013, 07:06:58 PM »

I have a new HP laptop with an Intel I7-4700MQ processor and NVIDIA GeForce GT 740M graphics. Graphics driver is the latest from NVIDIA. Open Hardware Monitor shows very heavy use of the GPU during Build Dense Cloud with PhotoScan 1.0 Build 1748, and the log shows the GPU contributing as much as the CPU. Clearly the GPU is not "crippled".

 

169

Feature Requests / Re: OBJ Texture Names Chunk Specific

« on: October 29, 2013, 12:03:30 PM »

Thanks!

170

General / Re: Best post processing in Lightroom

« on: October 22, 2013, 04:43:16 AM »

I adjust the images so that none of the areas which are needed are either saturated or "black". Setting of the controls depends on the images.

I use the Chromatic Aberration correction and vignetting correction in Lightroom since there are profiles available for my lenses. I make sure to turn off distortion correction.

171

General / Re: Accessing RAM

« on: October 09, 2013, 09:18:00 PM »

My experience is PhotoScan uses as much memory as it needs, up to using all the available memory.

The amount of memory needed depends on settings and can vary greatly. What settings are you using?

Generally alignment requires less memory than creating the dense point cloud and meshing. My strategy with large numbers of photos (up to 600 photos) has been to align all the photos together, and then create duplicate chunks. The bounding box in each chunk is adjusted to cover a portion of the object. The resulting meshes can be merged before exporting if desired.

172

Feature Requests / Re: recalculate selection

« on: September 27, 2013, 09:22:16 PM »

Simple to do.

1) Duplicate a chunk which has the desired cameras/photos aligned.

2) Adjust the size and orientation of the bounding box in the duplicated chunk to fit the area of the object where the higher quality is desired.

3) Optional - In the duplicated chunk disable the cameras/photos not needed with the revised bounding box. This is not required but will speed up building the geometry in the duplicated chunk.

4) Build geometry in the duplicated chunk with the desired quality.

5) Because the alignment of the photos between the two chunks was not changed the two chunks will have the same alignment. To have the chunks show in PhotoScan as aligned run Align Chunks for the two chunks using the Camera method. This should only take a few seconds.

173

General / Re: Best F-Stop for the best Data?

« on: September 24, 2013, 10:20:33 PM »

"Best" F-Stop depends on the shape of the subject and the lens characteristics, and can be a tradeoff between sharpness at the focused distance and depth of field. Most lens tests use flat subjects for testing purposes and the reported f-stop for best sharpness applies only to flat objects.

The optimum f-stop for overall sharpness for objects with "height" variation will be smaller (numerically higher) than the f-stop for flat objects. How much smaller is optimum depends on the amount of height variation, the sharpness of the lens and the variation of the sharpness with f-stop. More variation in height means depth of field is more important.

Lens test results and calculations could be used to determine optimum f-stop but experimentation is probably simpler.

174

General / Re: System hard freeze while GPUs processing with ATI7970 if using computer

« on: September 12, 2013, 11:51:05 PM »

I recall reading that PhotoScan varies GPU usage to maximize overall speed, and the amount of GPU usage depends on GPU speed, CPU speed and memory speed. But that's only a recollection.

175

General / Re: fixed focal length ?

« on: September 04, 2013, 02:11:06 AM »

I've had success using "blue tape" to hold a zoom lens in one position while taking a set of photos.

I also usually turn off auto-focus and tape the focus ring in one position for all photos taken at approximately the same distance from the subject..

176

General / Re: The Transform between length in 3D model and the truth

« on: August 28, 2013, 04:12:51 AM »

Geometry created in the standard edition of PhotoScan has arbitrary units and the scale will be different in each project. The scale of the PhotoScan geometry can be determined if the actual distance between two points of the geometry is known. Measure the distance between those two points in PhotoScan, and the scale will be the ratio of the distance in PhotoScan to the actual distance. This scale will work for all distances in that particular geometry.

177

General / Re: exporting model to CAD

« on: August 20, 2013, 09:43:56 PM »

As discussed in another thread several days ago http://www.agisoft.ru/forum/index.php?topic=1454.0

For the texture on an .obj mesh imported from PhotoScan to be seen in Rhino you may also need to edit the .obj file and .mtl file.

-  In the .mtl file edit the first line "newmtl Textured" Replace "Textured" with a unique name not used by any other texture in Rhino.

-  In the .obj file edit the second line "usemtl Textured"  Replace "Textured" with the same name used in the .mtl file

Agisoft is going to try to change PhotoScan so the file name is used instead of "Textured" which should eliminate the problem.  http://www.agisoft.ru/forum/index.php?topic=1380.0

178

General / Re: measure drawing?

« on: August 20, 2013, 09:40:07 PM »

When photographing a building for Photoscan identify several features which should be easy to identify after a mesh is created and textured. Measure and record the distances between these features. Process the images in Photoscan and obtain a mesh with texture. Export that mesh (I use .obj) and import it into AutoCAD, etc. Once in AutoCAD align the mesh as desired. Then select two of the features on the mesh which you previously identified and measured the distance between on the actual building. If you have several sets of features to select between use the ones which are largest distance apart which can be clearly identified on the building and which are the longest distance apart. The mesh can then be scaled so that the distance between the features in AutoCAD matches the actual distance. The scale ratio is (Distance on building) / (Distance on mesh as imported).

179

General / Re: Rhino doubts

« on: August 14, 2013, 11:04:51 PM »

I have scaled and rotated .obj meshes in Rhino which originated in Photoscan and were imported into Rhino. The texture is not affected by the scaling or rotation and continues to work properly. I've also trimmed the meshes and the texture continued to work properly.

180

General / Re: Export for Autocad

« on: August 13, 2013, 03:32:01 AM »

.obj export It's what I use for exporting to Rhino.