Frequently Asked Questions — COLMAP 3.8 documentation (2023)

Adjusting the options for different reconstruction scenarios and output quality

COLMAP provides many options that can be tuned for different reconstructionscenarios and to trade off accuracy and completeness versus efficiency. Thedefault options are set to for medium to high quality reconstruction ofunstructured input data. There are several presets for different scenarios andquality levels, which can be set in the GUI as Extras > Set options for ....To use these presets from the command-line, you can save the current set ofoptions as File > Save project after choosing the presets. The resultingproject file can be opened with a text editor to view the different options.Alternatively, you can generate the project file also from the command-lineby running colmap project_generator.

Extending COLMAP

If you need to simply analyze the produced sparse or dense reconstructions fromCOLMAP, you can load the sparse models in Python and Matlab using the providedscripts in scripts/python and scripts/matlab.

If you want to write a C/C++ executable that builds on top of COLMAP, there aretwo possible approaches. First, the COLMAP headers and library are installedto the CMAKE_INSTALL_PREFIX by default. Compiling against COLMAP as alibrary is described here. Alternatively, you canstart from the src/tools/example.cc code template and implement the desiredfunctionality directly as a new binary within COLMAP.

Fix intrinsics

By default, COLMAP tries to refine the intrinsic camera parameters (exceptprincipal point) automatically during the reconstruction. Usually, if there areenough images in the dataset and you share the intrinsics between multipleimages, the estimated intrinsic camera parameters in SfM should be better thanparameters manually obtained with a calibration pattern.

However, sometimes COLMAP’s self-calibration routine might converge indegenerate parameters, especially in case of the more complex camera models withmany distortion parameters. If you know the calibration parameters a priori, youcan fix different parameter groups during the reconstruction. ChooseReconstruction > Reconstruction options > Bundle Adj. > refine_* and checkwhich parameter group to refine or to keep constant. Even if you keep theparameters constant during the reconstruction, you can refine the parameters ina final global bundle adjustment by setting Reconstruction > Bundle adj.options > refine_* and then running Reconstruction > Bundle adjustment.

Principal point refinement

By default, COLMAP keeps the principal point constant during the reconstruction,as principal point estimation is an ill-posed problem in general. Once allimages are reconstructed, the problem is most often constrained enough that youcan try to refine the principal point in global bundle adjustment, especiallywhen sharing intrinsic parameters between multiple images. Please, refer toFix intrinsics for more information.

Increase number of matches / sparse 3D points

To increase the number of matches, you should use the more discriminativeDSP-SIFT features instead of plain SIFT and also estimate the affine featureshape using the options: --SiftExtraction.estimate_affine_shape=true and--SiftExtraction.domain_size_pooling=true. In addition, you should enableguided feature matching using: --SiftMatching.guided_matching=true.

By default, COLMAP ignores two-view feature tracks in triangulation, resultingin fewer 3D points than possible. Triangulation of two-view tracks can in rarecases improve the stability of sparse image collections by providing additionalconstraints in bundle adjustment. To also triangulate two-view tracks, unselectthe option Reconstruction > Reconstruction options > Triangulation >ignore_two_view_tracks. If your images are taken from far distance withrespect to the scene, you can try to reduce the minimum triangulation angle.

Reconstruct sparse/dense model from known camera poses

If the camera poses are known and you want to reconstruct a sparse or densemodel of the scene, you must first manually construct a sparse model by creatinga cameras.txt, points3D.txt, and images.txt under a new folder:

+── path/to/manually/created/sparse/model│ +── cameras.txt│ +── images.txt│ +── points3D.txt

The points3D.txt file should be empty while every other line in the images.txtshould also be empty, since the sparse features are computed, as described below. You canrefer to this article for more information about the structure ofa sparse model.

Example of images.txt:

1 0.695104 0.718385 -0.024566 0.012285 -0.046895 0.005253 -0.199664 1 image0001.png# Make sure every other line is left empty2 0.696445 0.717090 -0.023185 0.014441 -0.041213 0.001928 -0.134851 2 image0002.png3 0.697457 0.715925 -0.025383 0.018967 -0.054056 0.008579 -0.378221 1 image0003.png4 0.698777 0.714625 -0.023996 0.021129 -0.048184 0.004529 -0.313427 2 image0004.png

Each image above must have the same image_id (first column) as in the database (next step).This database can be inspected either in the GUI (under Database management > Processing),or, one can create a reconstruction with colmap and later export it as text in order to seethe images.txt file it creates.

To reconstruct a sparse map, you first have to recompute features from theimages of the known camera poses as follows:

colmap feature_extractor \ --database_path $PROJECT_PATH/database.db \ --image_path $PROJECT_PATH/images
(Video) Photogrammetry - 3D scan with just your phone/camera

If your known camera intrinsics have large distortion coefficients, you shouldnow manually copy the parameters from your cameras.txt to the database, suchthat the matcher can leverage the intrinsics. Modifying the database is possiblein many ways, but an easy option is to use the providedscripts/python/database.py script. Otherwise, you can skip this step andsimply continue as follows:

colmap exhaustive_matcher \ # or alternatively any other matcher --database_path $PROJECT_PATH/database.dbcolmap point_triangulator \ --database_path $PROJECT_PATH/database.db \ --image_path $PROJECT_PATH/images --input_path path/to/manually/created/sparse/model \ --output_path path/to/triangulated/sparse/model

Note that the sparse reconstruction step is not necessary in order to computea dense model from known camera poses. Assuming you computed a sparse modelfrom the known camera poses, you can compute a dense model as follows:

colmap image_undistorter \ --image_path $PROJECT_PATH/images \ --input_path path/to/triangulated/sparse/model \ --output_path path/to/dense/workspacecolmap patch_match_stereo \ --workspace_path path/to/dense/workspacecolmap stereo_fusion \ --workspace_path path/to/dense/workspace \ --output_path path/to/dense/workspace/fused.ply

Alternatively, you can also produce a dense model without a sparse model as:

colmap image_undistorter \ --image_path $PROJECT_PATH/images \ --input_path path/to/manually/created/sparse/model \ --output_path path/to/dense/workspace

Since the sparse point cloud is used to automatically select neighboring imagesduring the dense stereo stage, you have to manually specify the source images,as described here. The dense stereo stagenow also requires a manual specification of the depth range:

colmap patch_match_stereo \ --workspace_path path/to/dense/workspace \ --PatchMatchStereo.depth_min $MIN_DEPTH \ --PatchMatchStereo.depth_max $MAX_DEPTHcolmap stereo_fusion \ --workspace_path path/to/dense/workspace \ --output_path path/to/dense/workspace/fused.ply

Merge disconnected models

Sometimes COLMAP fails to reconstruct all images into the same model and henceproduces multiple sub-models. If those sub-models have common registered images,they can be merged into a single model as post-processing step:

colmap model_merger \ --input_path1 /path/to/sub-model1 \ --input_path2 /path/to/sub-model2 \ --output_path /path/to/merged-model

To improve the quality of the alignment between the two sub-models, it isrecommended to run another global bundle adjustment after the merge:

colmap bundle_adjuster \ --input_path /path/to/merged-model \ --output_path /path/to/refined-merged-model

Geo-registration

Geo-registration of models is possible by providing the 3D locations for thecamera centers of a subset or all registered images. The 3D similaritytransformation between the reconstructed model and the target coordinate frameof the geo-registration is determined from these correspondences.

The geo-registered 3D coordinates can either be extracted from the database(tvec_prior field) or from a user specified text file.For text-files, the geo-registered 3D coordinates of the camera centers forimages must be specified with the following format:

image_name1.jpg X1 Y1 Z1image_name2.jpg X2 Y2 Z2image_name3.jpg X3 Y3 Z3...

The coordinates can be either GPS-based (lat/lon/alt) or cartesian-based (x/y/z).In case of GPS coordinates, a conversion will be performed to turn those intocartesian coordinates. The conversion can be done from GPS to ECEF(Earth-Centered-Earth-Fixed) or to ENU (East-North-Up) coordinates. If ENU coordinatesare used, the first image GPS coordinates will define the origin of the ENU frame.It is also possible to use ECEF coordinates for alignment and then rotate the alignedreconstruction into the ENU plane.

Note that at least 3 images must be specified to estimate a 3D similaritytransformation. Then, the model can be geo-registered using:

colmap model_aligner \ --input_path /path/to/model \ --output_path /path/to/geo-registered-model \ --ref_images_path /path/to/text-file (or --database_path /path/to/databse.db) \ --ref_is_gps 1 \ --alignment_type ecef \ --robust_alignment 1 \ --robust_alignment_max_error 3.0 (where 3.0 is the error threshold to be used in RANSAC)
(Video) Neural Radiance fields: the easy way!

By default, the robust_alignment flag is set to 1. If this flag is set, a 3D similaritytransformation will be estimated with a RANSAC estimator to be robust to potential outliersin the data. In such case, it is required to provide the error threshold to be used in theRANSAC estimator.

Manhattan world alignment

COLMAP has functionality to align the coordinate axes of a reconstruction usinga Manhattan world assumption, i.e. COLMAP can automatically determine thegravity axis and the major horizontal axis of the Manhattan world throughvanishing point detection in the images. Please, refer to themodel_orientation_aligner for more details.

Mask image regions

COLMAP supports masking of keypoints during feature extraction by passing amask_path to a folder with image masks. For a given image, the correspondingmask must have the same sub-path below this root as the image has belowimage_path. The filename must be equal, aside from the added extension.png. For example, for an image image_path/abc/012.jpg, the mask wouldbe mask_path/abc/012.jpg.png. No features will be extracted in regions,where the mask image is black (pixel intensity value 0 in grayscale).

Register/localize new images into an existing reconstruction

If you have an existing reconstruction of images and want to register/localizenew images within this reconstruction, you can follow these steps:

colmap feature_extractor \ --database_path $PROJECT_PATH/database.db \ --image_path $PROJECT_PATH/images \ --image_list_path /path/to/image-list.txtcolmap vocab_tree_matcher \ --database_path $PROJECT_PATH/database.db \ --VocabTreeMatching.vocab_tree_path /path/to/vocab-tree.bin \ --VocabTreeMatching.match_list_path /path/to/image-list.txtcolmap image_registrator \ --database_path $PROJECT_PATH/database.db \ --input_path /path/to/existing-model \ --output_path /path/to/model-with-new-imagescolmap bundle_adjuster \ --input_path /path/to/model-with-new-images \ --output_path /path/to/model-with-new-images

Note that this first extracts features for the new images, then matches them tothe existing images in the database, and finally registers them into the model.The image list text file contains a list of images to extract and match,specified as one image file name per line. The bundle adjustment is optional.

If you need a more accurate image registration with triangulation, then youshould restart or continue the reconstruction process rather than justregistering the images to the model. Instead of running theimage_registrator, you should run the mapper to continue thereconstruction process from the existing model:

Or, alternatively, you can start the reconstruction from scratch:

colmap mapper \ --database_path $PROJECT_PATH/database.db \ --image_path $PROJECT_PATH/images \ --output_path /path/to/model-with-new-images

Note that dense reconstruction must be re-run from scratch after running themapper or the bundle_adjuster, as the coordinate frame of the model canchange during these steps.

Available functionality without GPU/CUDA

If you do not have a CUDA-enabled GPU but some other GPU, you can use all COLMAPfunctionality except the dense reconstruction part. However, you can useexternal dense reconstruction software as an alternative, as described in theTutorial. If you have a GPU with low compute poweror you want to execute COLMAP on a machine without an attached display andwithout CUDA support, you can run all steps on the CPU by specifying theappropriate options (e.g., --SiftExtraction.use_gpu=false for the featureextraction step). But note that this might result in a significant slow-down ofthe reconstruction pipeline. Please, also note that feature extraction on theCPU can consume excessive RAM for large images in the default settings, whichmight require manually reducing the maximum image size using--SiftExtraction.max_image_size and/or setting--SiftExtraction.first_octave 0 or by manually limiting the number ofthreads using --SiftExtraction.num_threads.

Multi-GPU support in feature extraction/matching

You can run feature extraction/matching on multiple GPUs by specifying multipleindices for CUDA-enabled GPUs, e.g., --SiftExtraction.gpu_index=0,1,2,3 and--SiftMatching.gpu_index=0,1,2,3 runs the feature extraction/matching on 4GPUs in parallel. Note that you can only run one thread per GPU and thistypically also gives the best performance. By default, COLMAP runs one featureextraction/matching thread per CUDA-enabled GPU and this usually gives the bestperformance as compared to running multiple threads on the same GPU.

Feature matching fails due to illegal memory access

If you encounter the following error message:

MultiplyDescriptor: an illegal memory access was encountered

or the following:

(Video) 03 - 3D mesh using Colmap and Meshlab (Photogrammetry 3/3)

ERROR: Feature matching failed. This probably caused by insufficient GPU

memory. Consider reducing the maximum number of features.

during feature matching, your GPU runs out of memory. Try decreasing the option--SiftMatching.max_num_matches until the error disappears. Note that thismight lead to inferior feature matching results, since the lower-scale inputfeatures will be clamped in order to fit them into GPU memory. Alternatively,you could change to CPU-based feature matching, but this can become very slow,or better you buy a GPU with more memory.

The maximum required GPU memory can be approximately estimated using thefollowing formula: 4 * num_matches * num_matches + 4 * num_matches * 256.For example, if you set --SiftMatching.max_num_matches 10000, the maximumrequired GPU memory will be around 400MB, which are only allocated if one ofyour images actually has that many features.

Trading off completeness and accuracy in dense reconstruction

If the dense point cloud contains too many outliers and too much noise, try toincrease the value of option --StereoFusion.min_num_pixels.

If the reconstructed dense surface mesh model using Poisson reconstructioncontains no surface or there are too many outlier surfaces, you should reducethe value of option --PoissonMeshing.trim to decrease the surface are andvice versa to increase it. Also consider to try the reduce the outliers orincrease the completeness in the fusion stage, as described above.

If the reconstructed dense surface mesh model using Delaunay reconstructioncontains too noisy or incomplete surfaces, you should increase the--DenaunayMeshing.quality_regularization parameter to obtain a smoothersurface. If the resolution of the mesh is too coarse, you should reduce the--DelaunayMeshing.max_proj_dist option to a lower value.

Improving dense reconstruction results for weakly textured surfaces

For scenes with weakly textured surfaces it can help to have a high resolutionof the input images (--PatchMatchStereo.max_image_size) and a large patch windowradius (--PatchMatchStereo.window_radius). You may also want to reduce thefiltering threshold for the photometric consistency cost(--PatchMatchStereo.filter_min_ncc).

Surface mesh reconstruction

COLMAP supports two types of surface reconstruction algorithms. Poisson surfacereconstruction [kazhdan2013] and graph-cut based surface extraction from aDelaunay triangulation. Poisson surface reconstruction typically requires analmost outlier-free input point cloud and it often produces bad surfaces in thepresence of outliers or large holes in the input data. The Delaunaytriangulation based meshing algorithm is more robust to outliers and in generalmore scalable to large datasets than the Poisson algorithm, but it usuallyproduces less smooth surfaces. Furthermore, the Delaunay based meshing can beapplied to sparse and dense reconstruction results. To increase the smoothnessof the surface as a post-processing step, you could use Laplacian smoothing, ase.g. implemented in Meshlab.

Note that the two algorithms can also be combined by first running the Delaunaymeshing to robustly filter outliers from the sparse or dense point cloud andthen, in the second step, performing Poisson surface reconstruction to obtain asmooth surface.

Speedup dense reconstruction

The dense reconstruction can be speeded up in multiple ways:

  • Put more GPUs in your system as the dense reconstruction can make use ofmultiple GPUs during the stereo reconstruction step. Put more RAM into yoursystem and increase the --PatchMatchStereo.cache_size,--StereoFusion.cache_size to the largest possible value in order tospeed up the dense fusion step.

  • Do not perform geometric dense stereo reconstruction--PatchMatchStereo.geom_consistency false. Make sure to also enable--PatchMatchStereo.filter true in this case.

  • Reduce the --PatchMatchStereo.max_image_size, --StereoFusion.max_image_sizevalues to perform dense reconstruction on a maximum image resolution.

  • Reduce the number of source images per reference image to be considered, asdescribed here.

  • Increase the patch windows step --PatchMatchStereo.window_step to 2.

  • Reduce the patch window radius --PatchMatchStereo.window_radius.

  • Reduce the number of patch match iterations --PatchMatchStereo.num_iterations.

  • Reduce the number of sampled views --PatchMatchStereo.num_samples.

  • To speedup the dense stereo and fusion step for very large reconstructions,you can use CMVS to partition your scene into multiple clusters and to pruneredundant images, as described here.

Note that apart from upgrading your hardware, the proposed changes might degradethe quality of the dense reconstruction results. When canceling the stereoreconstruction process and restarting it later, the previous progress is notlost and any already processed views will be skipped.

Reduce memory usage during dense reconstruction

If you run out of GPU memory during patch match stereo, you can either reducethe maximum image size by setting the option --PatchMatchStereo.max_image_size orreduce the number of source images in the stereo/patch-match.cfg file frome.g. __auto__, 30 to __auto__, 10. Note that enabling thegeom_consistency option increases the required GPU memory.

(Video) EON-XR User Webinar September 2021 - Photorealistic 360 experiences with the EON-XR & EON Merged XR

If you run out of CPU memory during stereo or fusion, you can reduce the--PatchMatchStereo.cache_size or --StereoFusion.cache_size specified ingigabytes or you can reduce --PatchMatchStereo.max_image_size or--StereoFusion.max_image_size. Note that a too low value might lead to veryslow processing and heavy load on the hard disk.

For large-scale reconstructions of several thousands of images, you shouldconsider splitting your sparse reconstruction into more manageable clusters ofimages using e.g. CMVS [furukawa10]. In addition, CMVS allows to pruneredundant images observing the same scene elements. Note that, for this usecase, COLMAP’s dense reconstruction pipeline also supports the PMVS/CMVS folderstructure when executed from the command-line. Please, refer to the workspacefolder for example shell scripts. Note that the example shell scripts forPMVS/CMVS are only generated, if the output type is set to PMVS. Since CMVSproduces highly overlapping clusters, it is recommended to increase the defaultvalue of 100 images per cluster to as high as possible according to youravailable system resources and speed requirements. To change the number ofimages using CMVS, you must modify the shell scripts accordingly. For example,cmvs pmvs/ 500 to limit each cluster to 500 images. If you want to use CMVSto prune redundant images but not to cluster the scene, you can simply set thisnumber to a very large value.

Manual specification of source images during dense reconstruction

You can change the number of source images in the stereo/patch-match.cfgfile from e.g. __auto__, 30 to __auto__, 10. This selects the imageswith the most visual overlap automatically as source images. You can also useall other images as source images, by specifying __all__. Alternatively, youcan manually specify images with their name, for example:

image1.jpgimage2.jpg, image3.jpgimage2.jpgimage1.jpg, image3.jpgimage3.jpgimage1.jpg, image2.jpg

Here, image2.jpg and image3.jpg are used as source images forimage1.jpg, etc.

Multi-GPU support in dense reconstruction

You can run dense reconstruction on multiple GPUs by specifying multiple indicesfor CUDA-enabled GPUs, e.g., --PatchMatchStereo.gpu_index=0,1,2,3 runs the densereconstruction on 4 GPUs in parallel. You can also run multiple densereconstruction threads on the same GPU by specifying the same GPU index twice,e.g., --PatchMatchStereo.gpu_index=0,0,1,1,2,3. By default, COLMAP runs onedense reconstruction thread per CUDA-enabled GPU.

Fix GPU freezes and timeouts during dense reconstruction

The stereo reconstruction pipeline runs on the GPU using CUDA and puts the GPUunder heavy load. You might experience a display freeze or even a program crashduring the reconstruction. As a solution to this problem, you could use asecondary GPU in your system, that is not connected to your display by settingthe GPU indices explicitly (usually index 0 corresponds to the card that thedisplay is attached to). Alternatively, you can increase the GPU timeouts ofyour system, as detailed in the following.

By default, the Windows operating system detects response problems from the GPU,and recovers to a functional desktop by resetting the card and aborting thestereo reconstruction process. The solution is to increase the so-called“Timeout Detection & Recovery” (TDR) delay to a larger value. Please, refer tothe NVIDIA Nsight documentation or to the Microsoftdocumentationon how to increase the delay time under Windows. You can increase the delayusing the following Windows Registry entries:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers]"TdrLevel"=dword:00000001"TdrDelay"=dword:00000120

To set the registry entries, execute the following commands using administratorprivileges (e.g., in cmd.exe or powershell.exe):

reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers /v TdrLevel /t REG_DWORD /d 00000001reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers /v TdrDelay /t REG_DWORD /d 00000120

and restart your machine afterwards to make the changes effective.

The X window system under Linux/Unix has a similar feature and detects responseproblems of the GPU. The easiest solution to avoid timeout problems under the Xwindow system is to shut it down and run the stereo reconstruction from thecommand-line. Under Ubuntu, you could first stop X using:

sudo service lightdm stop

And then run the dense reconstruction code from the command-line:

colmap patch_match_stereo ...

Finally, you can restart your desktop environment with the following command:

sudo service lightdm start
(Video) Lecture 18-RGB-D Visual Odometry

If the dense reconstruction still crashes after these changes, the reason isprobably insufficient GPU memory, as discussed in a separate item in this list.

FAQs

How long does Colmap take to run? ›

COLMAP completes the process in 15 hours; whereas CMPMVS takes over 20 hours. COLMAP pipeline is more comprehensive, since it takes image input and generates sparse/dense/mesh results.

Does Colmap use GPU? ›

By default, COLMAP runs one feature extraction/matching thread per CUDA-enabled GPU and this usually gives the best performance as compared to running multiple threads on the same GPU.

What is Colmap used for? ›

COLMAP is a general-purpose, end-to-end image-based 3D reconstruction pipeline (i.e., Structure-from-Motion (SfM) and Multi-View Stereo (MVS)) with a graphical and command-line interface. It offers a wide range of features for reconstruction of ordered and unordered image collections.

How to start COLMAP? ›

For convenience, the pre-built binaries for Windows contain both the graphical and command-line interface executables. To start the COLMAP GUI, you can simply double-click the COLMAP. bat batch script or alternatively run it from the Windows command shell or Powershell.

How do I zoom in Colmap? ›

Shift model: Right-click or <CTRL>-click (<CMD>-click) and drag. Zoom model: Scroll. Change point size: <CTRL>-scroll (<CMD>-scroll). Change camera size: <ALT>-scroll.

What do you understand by bundle adjustment? ›

Bundle adjustment describes the sum of errors between the measured pixel coordinates uij and the re-projected pixel coordinates. The re-projected pixel coordinates are computed by structure(3D points coordinates in world frame) and camera parameters.

Should I use CPU or GPU for PhysX? ›

PhysX runs faster and will deliver more realism by running on the GPU. Running PhysX on a mid-to-high-end GeForce GPU will enable 10-20 times more effects and visual fidelity than physics running on a high-end CPU.

What graphics card is the 5700G equivalent to? ›

Ryzen 7 5700G is roughly equivalent to RX 550 performance.

Does emulator use GPU or CPU? ›

If your GPU hardware and drivers are compatible, the emulator uses the GPU. Otherwise, the emulator uses software acceleration (using your computer's CPU) to simulate GPU processing.

What is Col map? ›

COLMAP is a general-purpose Structure-from-Motion (SfM) and Multi-View Stereo (MVS) pipeline with a graphical and command-line interface. It offers a wide range of features for reconstruction of ordered and unordered image collections. The software is licensed under the new BSD license.

Is Colmap free? ›

COLMAP is a free photogrammetry software available for download from Github. You can run it either from the command-line or executively like any other program with a GUI.

Which key is used for zooming? ›

Keyboard only

Press and hold Ctrl and press - (minus) key or + (plus) key to zoom out or in of a web page or document.

How do you Unzoom a view? ›

Here's how you can zoom in and out on your computer using your keyboard:
  1. Press the "Control" key. ...
  2. Locate the plus and minus keys on your keyboard. ...
  3. If you want to zoom in, press the plus key while holding down the "Control" key.
  4. If you want to zoom out, press the minus key while holding down the "Control" key.

How do you zoom in mirror view? ›

Tap the Camera Control icon. Use the icons on the Camera Control popup to zoom and pan until the camera is in the position you need. Note: You can click the toggle next to Mirror Effect if you want this option enabled for your own video display (the display of your Zoom Room will look like a mirror).

What are two types of bundling? ›

Bundling usually consists of giving consumers an option to buy a set of items together as a package at a lower price than what they would pay to buy them all individually, in a process known as mixed bundling. However, there also exists an alternative, rarer form of this strategy called pure bundling.

What is minimum number of control points for bundle adjustment? ›

The minimum number of control points set as constraints to run the bundle adjustment is 3. However ,a higher number is advised, especially when accuracy is important.

Do games still use PhysX? ›

Initially, video games supporting PhysX were meant to be accelerated by PhysX PPU (expansion cards designed by Ageia). However, after Ageia's acquisition by Nvidia, dedicated PhysX cards have been discontinued in favor of the API being run on CUDA-enabled GeForce GPUs.

Is it faster to render with CPU or GPU? ›

Modern GPUs offer superior processing power and memory bandwidth than traditional CPU. In addition, GPU is more efficient when it comes to processing tasks that require multiple parallel processes. In fact, GPU rendering is about 50 to 100 times faster than CPU rendering.

Does PhysX use Cuda? ›

PhysX rigid body simulation can be configured to take advantage of CUDA capable GPUs under Linux or Windows. This provides a performance benefit proportional to the arithmetic complexity of a scene.

What CPU is equivalent to Ryzen 7 5700G? ›

Intel Core i7-11700

What is the fastest integrated graphics? ›

The AMD Ryzen 5 5600G is overall the best CPU with integrated graphics. This 6-core 12-thread unlocked desktop processor comes with Radeon graphics to boost the overall performance of your system.

How much RAM can a Ryzen 7 5700G handle? ›

The Ryzen 7 5700G supports up to 64GB of RAM.

Is RAM important for emulation? ›

RAM. Unlike in the majority of other build situations, RAM is something that should be prioritized to some extent for an emulation build. Everything from shaders and other graphics assets to save-relevant processes to some pre-loading functions can make use of RAM capacity.

How much RAM is needed to run the emulator? ›

Emulator system requirements

For the best experience, you should use the emulator in Android Studio on a computer with the following specs: 16GB RAM. 64-bit Windows, macOS, Linux, or ChromeOS operating system. 16GB disk space.

Which emulator uses less RAM? ›

3Top 5 Best Android Emulators for Low-End PC
Android emulatorCostMinimum Requirements
BlueStacksFree2GB of RAM 4GB of hard disk
NoxPlayerFree2GB of RAM 1.5GB of hard disk
LDPlayerFree2GB of RAM 36GB of hard disk
Droid4XFree1GB of RAM 20GB of hard disk
1 more row
10 Nov 2022

What is Col texture? ›

Col maps control the albedo of a model. Albedo is the overall color of an object. Surfaces with higher albedo reflect more light and appear brighter than surfaces with low albedo. This corresponds to the base color input of Blender's Principled Shader.

What are the 3 types of north on a military map? ›

A tale of three norths
  • True north is right at the top of the planet, at the geographic North Pole. The earth spins around this point so it never changes position. ...
  • Magnetic north is the direction that a compass will point to. ...
  • Grid north is the direction that the grid lines on a map point to.

How accurate is photogrammetry? ›

At 1 part in 30,000 on a 3m object, point positions would be accurate to 0.1mm at 68% probability (one sigma). This is relative accuracy. To find the absolute accuracy the project must be scaled and or have control points defined. Then the accuracy of these scales and control points affect the absolute accuracy.

Who invented photogrammetry? ›

In 1849, Aimé Laussedat (April 19, 1819 - March 18, 1907) was the first person to use terrestrial photographs for topographic map compilation. He is referred to as the "Father of Photogrammetry".

Does 3D modeling use GPU? ›

GPUs are vital for 3D rendering, and should be one of your biggest priorities. If you don't have a graphics card, you probably won't get very far. There are a few different ways to evaluate graphics cards, but one of the industry standards is currently the NVIDIA GTX series.

Does QuPath use GPU? ›

Does QuPath use my graphic card (GPU)? ¶ Generally no… our current focus is the stability and functionality – and finding efficient ways to do things that don't require any particular hardware.

Does 3D Modelling use GPU? ›

For people who do a lot of 3D graphic works, it is highly recommended to choose NVIDIA GPUs to achieve appropriate rendering speeds. Among the best GPUs include the NVIDIA RTX 3090, NVIDIA RTX 3080 Ti, NVIDIA RTX 3080, and NVIDIA RTX 3070.

Does yolov5 use GPU? ›

Bug. Yolo does not learn with gpu, however it learns with cpu.

Does RAM matter for 3D rendering? ›

As long as you have an 8GB DDR4 RAM stick, you're good to go (in most cases). However, even though 8GB is the minimum requirement for 3D rendering, consider having a 16GB or a 32GB one for a better multitasking experience.

Does RAM affect 3D modeling? ›

Ram memory

RAM isn't the most important component for your rendering work, but it still matters. However, as 3D rendering software solutions are getting more sophisticated each day, they require more RAM.

What RAM is good for 3D modeling? ›

Modern systems all use DDR4 RAM. While 3D design programs tend to need a lot of memory, we recommend having at least 16GB to 32 GB of RAM for a professional 3D design. The more RAM you have, the smoother your computer will run.

What graphics cards use GDDR6X? ›

Micron has created the world's fastest discrete graphics memory solution: GDDR6X. Launched with NVIDIA on the GeForce® RTX™ 3090 and GeForce® RTX™ 3080 GPUs, GDDR6X takes graphics to new levels of gaming realism and unleashes high-performance AI inference.

What GPU does Pixar use? ›

"Pixar has long used NVIDIA GPU technology to push the limits of what is possible in animation and the filmmaking process," said Steve May, vice president and CTO at Pixar. "NVIDIA's particular QMC implementation has the potential to enhance rendering functionality and significantly reduce our rendering times."

Can you run a 5600G with a graphics card? ›

If that comes to pass, you won't need to start from scratch with the Ryzen 5 5600G. You can still slot a graphics card into a machine built around this chip and expect top performance out of it. And if you do, you'll still have an AMD Zen 3-powered six-core CPU able to keep up.

Which processor is best for 3D modeling? ›

Best CPU for 3D Rendering
CPU NameCoresPerformance/Dollar
AMD Ryzen 5 2600611.365
AMD Ryzen 5 2600X610.897
AMD Ryzen 7 2700X810.806
AMD Ryzen 7 2700810.524
66 more rows

Is RAM important for rendering? ›

So, yes, amount of RAM matters a lot, it can make or break your render. Have enough RAM and you'll get the full speed of the CPU or GPU that you bought for the system, run out and you'll be waiting far longer for those pixels to show up.

How many cores do you need for 3D rendering? ›

You can render on pretty much any type of laptop or desktop computer but choose a workstation-class machine as the components and cooling are designed specifically for compute intensive workloads. Laptops typically peak at 4 CPU cores and 32GB RAM so are best suited to entry-level rendering.

Can YOLOv5 run on CPU? ›

The benchmarking script supports YOLOv5 models using DeepSparse, ONNX Runtime (CPU), and PyTorch.

How do I make my YOLOv5 faster? ›

Increase Speeds

Reduce model size, i.e. YOLOv5x -> YOLOv5l -> YOLOv5m -> YOLOv5s -> YOLOv5n. Use half precision FP16 inference with python detect.py --half and python val.py --half. Use a faster GPUs, i.e.: P100 -> V100 -> A100. Export to ONNX or OpenVINO for up to 3x CPU speedup (CPU Benchmarks)

How do you speed up YOLOv5 training? ›

If you would like to increase your training speed some options are:
  1. Increase --batch-size.
  2. Reduce --img-size.
  3. Reduce model size, i.e. from YOLOv5x -> YOLOv5l -> YOLOv5m -> YOLOv5s.
  4. Train with multi-GPU DDP at larger --batch-size.
  5. Train with a cached dataset: python train.py --cache.

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