3DFlow Zephyr - Bounding Box

there's a tool that you can use in order to speed up the process inside structure from motion software that's specifically related to the dense point cloud building or calculation that's the bounding box or the region of processing that's a kind of volume that you can define or you can enlarge or you can reduce in order to focus the attention your attention and the attention of the structure from motion software on the points on the points of the sparse point cloud that you'd like to treat do you like to take in account in order to generate the dense point cloud if you have a huge a big area a big surface and you actually want to have a dance point cloud of just a portion of that surface you can instead of removing points from the sparse point cloud you can reduce the surface the area the volume of calculation using the bounding box bounding box is also called region of calculation it depends on the structure from motion software that you are working on in this video I'd like to show you how to treat the bounding box inside 3d flow Xavier and so this this is a sparse point cloud that I generated with Zephyr it's water stream I'm not sure that you can appreciate that but it's water simply czar the pictures the position of the cameras and this is the the surface imagine that you'd like to reduce the area that you'd like the surface the volume that you'd like to use for the - point cloud calculation just add the very central part of this of this stream so you'd like to get rid of these side areas and also this and this part of the on this 3d model you can do it using the bounding box and if you do that everything that is inside the bounding box will be taken in account from the software from zeph you'd have it then it's outside the bounding box will be discarded so will not be considered in the dance without calculation and in the next processing so the mesh and the mesh plus the texture and that's a big deal because dense point cloud required generally speaking requires a lot of time for processing it and so if you better define the surface you reduce the surface to the points that you really need you can really speed up the process so how can you access to the bounding box tool inside the field you can do that by two ways there's one way but is seen bounding box added bounding box for right click in the main window on main area of the field bounding box idiot bounding box that's basically the same when you when you activate this this tool you can see this volume that you can move you can rotate you can alert you can translate this is the volume that will be considered by it's a fear for the calculation of the dense point cloud everything that it's inside it so that it's inside this volume that is highlighted with a kind of light blue color will be calculated but you can you can rotate it you can move along the three axis XYZ you can enlarge or reduce so if you'd like to rotate the bounding box you just have to choose which is the the axis as a reference for rotation that's the y axis so if you click on one of this circle you have to highlight it and click and move the mouse it's just rotating along the y axis you can do that that you can do the same for the x axis so choose the right the red circle and move along it or you can use the z-axis and that's basically the same choose the blue circle and click and drag if you click just near it it doesn't work you need to highlight and then rotate but you may need like to you may want to move without rotation so you can choose one of the three X's X sorry X red Y green and blue that and just click on this X this segment to define the axis click and move click and drag and this this volume will will move all the way to this direction or the other one on that x-axis you can do that let's say you can do the same on the y-axis you can do the same on the x-axis finally there's the the third movement the third modification that you can do is enlarge or reduce it so for enlarging or reducing that is called scale inside the file you have to click there you have to highlight one of this face a rectangular shape you have to bring the mouse bring the arrows or over it let this let this face highlight and then you can click and drag a moon just to move the this side of the this solid in order to make it bigger or make it slowly slow and make it I'm sorry smaller if you are quite familiar with the extrude tool in software like sketch Sketchup it's basically the same thing so you have to you can move you have to alight the face and click and drag for modifying the modifying this this value alright if something if you'd like to go back to the original original volume that you hat you can always you can always go back and sorry about that just click here reset and the software will bring you back to the original that volume that it showed you when you just launched this tool for the very first time but you can also instead of having all this free movement available and maybe it could be a little bit messy especially for for particular 3d models for tricky surfaces you can fix one two or three of these movements in order to focus your attention to just one of them at step-by-step so you have to click here in this case each of this movement are available are admitted translate rotate scale if you click here on translate look at this axis they will disappear okay that means that you can you can no longer rotate you can no longer translate you can no longer move this volume on the XY and z axis you just you can now you can just rotate or make it bigger or all or smaller you can scale it if you wrote if you like to fix the rotation just click here and rotation circles disappear so now you can just basically move along this this faces in order to scale it if you click over it you can you basically you just see the bounding box but you can you cannot edit it it in any way that's nice because if you just have to if you like just to focus on the translation you just click on it and move it as you want without bothering about the rotation and that's the same for the rotation and that's the same for you can just rotate it without without messing it with movement along the z-axis and that's the same with a scale factor so you just scale without having any other distractions on the 3d in the 3d in 3d area let's go back to reset there's another tool here that's the smart reset which basically that's the same if I click reset the software bring me back to the smart reset smart reset it's a kind of solution let's say solution that the software gives you in order to best define the volume of calculation considering the sparse point cloud that's inside it it's kind of conservative solution is not gonna get you rid of any point of this part one company it's not too big either let's write and see how we can effectively edit the bounding box in order to fixing a portion of the central part of this stream in order to have a very much more quicker calculation of the dance point cloud' so I think that one of the best thing to do in this case is moving to the moving to the to the top view and so you can go here see camera view from top in this case I can see the model just from the top from above so I can see the X&Y plane and there's no the the z-axis is just coming towards me out from the screen it's not an orthographic projection as you can see there's a perspective here you can see this side of this part of the people the shape that I can clearly see that's due to perspective I can move to the orthographic projection just by clicking here and you can see that this part this the part that you just sewn before they disappear just because the the software just projected everything on the two dimension well actually it's not it's still it is still a 3d model but this view is projected in the two-dimensional XY plane so before before reciting the bounding box but before making it smaller I think that it's much better to rotate it in order to have one of this side parallel to the central portion of this dream so let's let's make the rotation active so I'm gonna click here and I'm gonna rotate it around along the z axis so I'm gonna hitting clicking the the blue circle and highlight it and moving around in order to have this side parallel to the central portion of this bounding box now now that I did it I need to resize it I need to making it smaller in order to highlight or include just this part just this point of the sparse point cloud so I'm gonna exit from the orthographic projection because now I need to move it in the 3d I can I can still move it in the 3d but it's still not a graphic projection and it could be a little bit tricky for the orbit so let's go to scene camera remover - graphic projection and I think that it's much better now so now I am gonna fix the rotation because I don't want it to be rotated any more and just using the scale the scale tool so I'm gonna highlight this face I'm gonna move it all the way to the left this point that will be outside the 3d this shape will not be taking an account in the calculation in the dance part ow I'm gonna move it all the way this way and then I'm gonna move in this way and that me maybe more here and then I'd like to to move this side all the way down here as you can see I cannot I cannot pull it I need to push it so I need to rotate the model here and select this face and push it all the way to the point that I'd like to I think that it's its best and that's it if I need to I move it too much to the on the x-direction I can even reduce a little bit of Z information so the elevation of this the shape and that's it let me go back to the let me go back to the top view view from top okay maybe I I can even translate a little bit so I'm gonna deactivate the scale button and activate the translate and just moving all the way here all over moving along the x-axis that's it basically that that's it I can I think that's fine in this case all these points that are outside this volume will not be taking an account I've been taking an account just the points that are inside and I can assure that that's a big deal because all these points will not be taken account and the software will speed up the dense point cloud processing if you click if you close you can export this bounding box as an XML file or if you have a bounding box in an XML file you can import it if I if I quit this tool the bounding box disappears but it's still on the software will still take it in account for the processing you can also choose to have the bounding box always visible so go back to the bounding box edit bounding box and just flag this tool as you can see the bounding box is still the one we edited a couple of minutes ago click here always show the bounding box and if you quit this tool the bounding box is still there and you can you can no longer edit you have to access the Edit tool but you can see you can clearly see it in order to appreciate what's inside and what's outside the bounding box so basically this video is over I thought I I thought I would have talked for much less time so it's it's almost 15 minutes and I'm talking about the bounding box but I think that bounding box is really important because it really can speed up the process getting rid of all the points that you don't want considering the fact that mmm when you align pictures for the very first time you do not have the chance for choosing a bounding box the bounding box will be edited just after the sparse point cloud has been calculated and that's visible in the 3d area so starting from the sparse point cloud for of the matching matching points you can define a bounding box if you define a bounding box the dense point cloud will be will be calculated based on the point inside the bounding box and that will be for the mesh tool because the mass you will refer to the dense point cloud so pay attention to the bounding box but you can always make some new processing with another bounding box a bigger one a smaller one it depends on what you'd like to define what would like to 3d reconstruct for from the pictures that you've just editing and compose your data set I hope that this video was useful feel free to share it feel free to connect with me awwwh recall talks calm thank you so much for watching and I'll see you in the next one ciao

Channel: Metrical Talks

Views: 416

Keywords: zephyr, 3dflow, 3dflow zephyr, bounding box, photogrammetry, structure from motion, sfm, metrical talks, tutorial, how to

Id: 0syLMQzcbnE

Length: 17min 25sec (1045 seconds)

Published: Thu May 21 2020