t file** - ply file with just x,y,z locations. I got it from a 3d scanner. Here is how first few lines of file looks like - ply format ascii 1.0 comment VCGLIB generated element vertex 6183 property float x property float y property float z end_header -32.3271 -43.9859 11.5124 -32.0631 -43.983 11.4945 12.9266 -44.4913 28.2031 13.1701 -44.4918 28.2568 13.4138 -44.4892 28.2531 13.6581 -44.4834 28.1941 13.9012 -44.4851 28.2684 ... ... ... In case you need the data - please email me on **nisha.m234@gmail.com**. **Algorithm:** I am trying to find principal curvatures for extracting the ridges and valleys. The steps I am following is: 1. Take a point x 2. Find its k nearest neighbors. I used k from 3 to 20. 3. average the k nearest neighbors => gives (_x, _y, _z) 4. compute covariance matrix 5. Now I take eigen values and eigen vectors of this covariance matrix 6. I get u, v and n here from eigen vectors. u is a vector corresponding to largest eigen value v corresponding to 2nd largest n is 3rd smallest vector corresponding to smallest eigen value 7. Then for transforming the point(x,y,z) I compute matrix T T = [ui ] [u ] [x - _x] [vi ] = [v ] x [y - _y] [ni ] [n ] [z - _z] 8. for each i of the k nearest neighbors:<br> [ n1 ] [u1*u1 u1*v1 v1*v1] [ a ]<br> [ n2 ] = [u2*u2 u2*v2 v2*v2] [ b ] <br> [... ] [ ... ... ... ] [ c ] <br> [ nk ] [uk*uk uk*vk vk*vk]<br> Solve this for a, b and c with least squares 9. this equations will give me a,b,c 10. now I compute eigen values of matrix [a b b a ] 11. This will give me 2 eigen values. one is Kmin and another Kmax. **My Problem:** The output is no where close to finding the correct Ridges and Valleys. I am totally Stuck and frustrated. I am not sure where exactly I am getting it wrong. I think the normal's are not computed correctly. But I am not sure. I am very new to graphics programming and so this maths, normals, shaders go way above my head. Any help will be appreciated. **PLEASE PLEASE HELP!!** **Resources:** I am using Visual Studio 2010 + Eigen Library + ANN Library. **Other Options used** I tried using MeshLab. I used ball pivoting triangles remeshing in MeshLab and then applied the polkadot3d shader. If correctly identifies the ridges and valleys. But I am not able to code it. **My Function:** //the function outputs to ply file void getEigen() { int nPts; // actual number of data points ANNpointArray dataPts; // data points ANNpoint queryPt; // query point ANNidxArray nnIdx;// near neighbor indices ANNdistArray dists; // near neighbor distances ANNkd_tree* kdTree; // search structure //for k = 25 and esp = 2, seems to got few ridges queryPt = annAllocPt(dim); // allocate query point dataPts = annAllocPts(maxPts, dim); // allocate data points nnIdx = new ANNidx[k]; // allocate near neigh indices dists = new ANNdist[k]; // allocate near neighbor dists nPts = 0; // read data points ifstream dataStream; dataStream.open(inputFile, ios::in);// open data file dataIn = &dataStream; ifstream queryStream; queryStream.open("input/query.
pts", ios::in);// open data file queryIn = &queryStream; while (nPts < maxPts && readPt(*dataIn, dataPts[nPts])) nPts++; kdTree = new ANNkd_tree( // build search structure dataPts, // the data points nPts, // number of points dim); // dimension of space while (readPt(*queryIn, queryPt)) // read query points { kdTree->annkSearch( // search queryPt, // query point k, // number of near neighbors nnIdx, // nearest neighbors (returned) dists, // distance (returned) eps); // error bound double x = queryPt[0]; double y = queryPt[1]; double z = queryPt[2]; double _x = 0.0; double _y = 0.0; double _z = 0.0; #pragma region Compute covariance matrix for (int i = 0; i < k; i++) { _x += dataPts[nnIdx[i]][0]; _y += dataPts[nnIdx[i]][1]; _z += dataPts[nnIdx[i]][2]; } _x = _x/k; _y = _y/k; _z = _z/k; double A[3][3] = {0,0,0,0,0,0,0,0,0}; for (int i = 0; i < k; i++) { double X = dataPts[nnIdx[i]][0]; double Y = dataPts[nnIdx[i]][1]; double Z = dataPts[nnIdx[i]][2]; A[0][0] += (X-_x) * (X-_x); A[0][1] += (X-_x) * (Y-_y); A[0][2] += (X-_x) * (Z-_z); A[1][0] += (Y-_y) * (X-_x); A[1][1] += (Y-_y) * (Y-_y); A[1][2] += (Y-_y) * (Z-_z); A[2][0] += (Z-_z) * (X-_x); A[2][1] += (Z-_z) * (Y-_y); A[2][2] += (Z-_z) * (Z-_z); } MatrixXd C(3,3); C <<A[0][0]/k, A[0][1]/k, A[0][2]/k, A[1][0]/k, A[1][1]/k, A[1][2]/k, A[2][0]/k, A[2][1]/k, A[2][2]/k; #pragma endregion EigenSolver<MatrixXd> es(C); MatrixXd Eval = es.eigenvalues().real().asDiagonal(); MatrixXd Evec = es.eigenvectors().real(); MatrixXd u,v,n; double a = Eval.row(0).col(0).value(); double b = Eval.row(1).col(1).value(); double c = Eval.row(2).col(2).value(); #pragma region SET U V N if(a>b && a>c) { u = Evec.row(0); if(b>c) { v = Eval.row(1); n = Eval.row(2);} else { v = Eval.row(2); n = Eval.row(1);} } else if(b>a && b>c) { u = Evec.row(1); if(a>c) { v = Eval.row(0); n = Eval.row(2);} else { v = Eval.row(2); n = Eval.row(0);} } else { u = Eval.row(2); if(a>b) { v = Eval.row(0); n = Eval.row(1);} else { v = Eval.row(1); n = Eval.row(0);} } #pragma endregion MatrixXd O(3,3); O <<u, v, n; MatrixXd UV(k,3); VectorXd N(k,1); for( int i=0; i<k; i++) { double x = dataPts[nnIdx[i]][0];; double y = dataPts[nnIdx[i]][1];; double z = dataPts[nnIdx[i]][2];; MatrixXd X(3,1); X << x-_x, y-_y, z-_z; MatrixXd T = O * X; double ui = T.row(0).col(0).value(); double vi = T.row(1).col(0).value(); double ni = T.row(2).col(0).value(); UV.row(i) << ui * ui, ui * vi, vi * vi; N.row(i) << ni; } Vector3d S = UV.colPivHouseholderQr().solve(N); MatrixXd II(2,2); II << S.row(0).value(), S.row(1).value(), S.row(1).value(), S.row(2).value(); EigenSolver<MatrixXd> es2(II); MatrixXd Eval2 = es2.eigenvalues().real().asDiagonal(); MatrixXd Evec2 = es2.eigenvectors().real(); double kmin, kmax; if(Eval2.row(0).col(0).value() < Eval2.row(1).col(1).value()) { kmin = Eval2.row(0).col(0).value(); kmax = Eval2.row(1).col(1).value(); } else { kmax = Eval2.row(0).col(0).value(); kmin = Eval2.row(1).col(1).value(); } double thresh = 0.0020078; if (kmin < thresh && kmax > thresh ) cout << x << " " << y << " " << z << " " << 255 << " " << 0 << " " << 0 << endl; else cout << x << " " << y << " " << z << " " << 255 << " " << 255 << " " << 255 << endl; } delete [] nnIdx; delete [] dists; delete kdTree; annClose(); } Thanks, NISHA…
ou will see all of the available components on a ribbon at once so there is no need to keep clicking drop down menus.
It's all about discoverability with GH. What if you're a beginner and don't know about the Create Facility (dbl click canvas) how can you find Extr?
Even if you hover over every component or use the drop down lists you will not see the name Extr appear anywhere.
Sure it makes sense that Extr is short for Extrude but it's also the Nick Name of Extrude to Point component
So you can easily miss the fact that one has a Distance Input verses a Point Input.
I think I made the move to Icons around about the move from version 0.5 to 0.6, possibly before. I initially thought that I would go back to text because I loved the mono chromatic look of the text but I soon realised that Icons were the way forward. The greatest benefit is speed. You don't need to digest and decipher every component (which is written 90 degrees to the norm).
I'm not saying you should move to Icons forthwith but at least consider that once you have a better knowledge and understanding of GH, Icons will set you free.
My top ten tips that I would highly recommend to anyone wanting to better themselves with GH.
1) Turn on Draw Icons
2) Turn on Draw Fancy Wires
3) Turn on Obscure Components
4) Use the Create Facility like a Command Line eg "Slider=-1<0.75<2" or "Shiftlist=-1"
5) Use Component Aliases to customise your use of the Create Facility eg giving the Point XYZ component an alias of XYZ will bring it up as the first option on the Create Facility as opposed to the other possibilities.
6) Try to answer other people's questions even if it's not relevant to your own area. By looking into solving a problem outside of your comfort zone and then posting your results it is very rewarding but it also lets you see the other approaches that get posted in a new light.
7) Take the time to understand Data/Path structures.
8) Buy a second monitor - There is nothing that can compare to real estate when working in Grasshopper.
9) Read Rajaa Issa's Essential Mathematics
10) Pick a panel in a tab on the ribbon and get to know every component inside and out and then move on. Start with the Sets Tab > List Panel…
Ladybug + Honeybee:
(Follow steps 0-4 for basic functionality and 0-9 for full functionality)
0. If you have an old version of LB+HB, download the file here (https://app.box.com/s/ds96em9l6stxpcw8kgtf)
and open it in Grasshopper to remove your old Ladybug and Honeybee version.
1. Make sure that you have a working copy of both Rhino and Grasshopper installed.
2. Open Rhino and type "Grasshopper" into the command line (without quotations). Wait for grasshopper to load.
3. Install GHPython 0.6.0.3 by downloading the file at this link (http://www.food4rhino.com/project/ghpython?ufh) and
drag the .gha file onto the Grasshopper canvas.
4. Select and drag all of the userObject files (downloaded with this instructions file) onto your Grasshopper canvas.
You should see Ladybug and Honeybee appear as tabs on the grasshopper tool bar.
(If you are reading this instruction on github you can download them from http://www.food4rhino.com/project/ladybug-honeybee)
5. Restart Rhino and Grasshopper. You now have a fully-functioning Ladybug. For Honeybee, continue to the following:
6. Install Radiance to C:\Radiance by downloading it from this link (https://github.com/NREL/Radiance/releases/download/4.2.2/radiance-4.2.2-win32.exe) and running the exe.
7. Install Daysim 4.0 for Windows to C:\DAYSIM by downloading it at this link (http://daysim.ning.com/page/download) and running the exe.
8. Install EnergyPlus 8.1 to C:\EnergyPlusV8-1-0 by going to the DOE website (http://apps1.eere.energy.gov/buildings/energyplus/energyplus_download.cfm), making an account, going to "download older
versions of EnergyPlus, selecting 8.1 and running the exe.
9. Copy falsecolor2.exe (http://pyrat.googlecode.com/files/falsecolor2.exe) and evalglare.exe (http://www.ise.fraunhofer.de/en/downloads-englisch/software/evalglare_windows.zip/at_download/file) to C:\Radiance\bin
10. You now have a fully-working version of Ladybug + Honeybee. Get started visualizing weather data with these video tutorials (https://www.youtube.com/playlist?list=PLruLh1AdY-Sj_XGz3kzHUoWmpWDXNep1O).
After I've done all the above I followed this video
https://vimeo.com/96155674
And everything works well.
…
nted" in space (at instance definition creation phase): indicates the obvious fact that if garbage in > garbage out (try it).
2. Load the GH thing. Task for you: Using Named Views locate the points of interest as described further and make a suitable view. That way you can navigate rather easily around (hope dies last).
3. Your attractors are controlled from here:
The slider in blue picks some attractor to play with. You can use this while the K2 is running.
4. Don't change anything here (think of it as a black box: who cares how it works? nobody actually):
5. Enable the other "black box": job done your real-life stuff is placed:
6. Enable the solver: your "real-life" things start to bounce around:
7. Go there are play with the slider. A different attractor yields an other solution:
8. With real-life things in place if you disable the C# ... they are instantly deleted and you are back in lines/points and the likes:
9. Either with instance definitions or Lines/points change ... er ... hmm ... these "simple" parameters and discover the truth out there:
10. Since these are a "few" and they affect the simulation with a variety of ways ... we need a "self calibrating" system: some mini big Brother that does the job for us. Kinda like applying safely the brakes when it rains (I hate ABS mind).
NOTE: the rod with springs requires some additional code ,more (that deals with NESTED instance definitions) in order to (b) bounce as a whole and at the same time (b) elongates or shrinks a bit.
More soon.
…
ng/702/30
EDIT: DK2 works, not with positional tracking yet (14/09/15)
Source is here:
https://github.com/provolot/RhinoRift
Steps:
1) Download these files (also attached below):
https://github.com/provolot/oculus-grasshopper/raw/master/oculus-grasshopper_v0.4.ghx
https://github.com/provolot/oculus-grasshopper/raw/master/OpenTrackRiftGrasshopperUDP.ini
https://github.com/provolot/oculus-grasshopper/raw/master/oculus-grasshopper-test_v0.1.3dm
2) Download OpenTrack - http://ananke.laggy.pk/opentrack/, and setup/install. Once installed, double-click to open.
3) In OpenTrack, load the 'OpenTrackRiftGrasshopperUDP.ini' profile. Click the 'Start' button and move your Rift around - make sure that it looks like the Yaw/Pitch/Roll data is being sent. TX/TY/TZ will all be 0, as Oculus doesn't have absolute positioning data.
4) In Rhino, open the test 3dm. You'll notice that there are two viewports - called 'LeftEye' and 'RightEye'. These have been placed to mimic where the screens should be for the Oculus Rift --- but only when Rhino is in fullscreen mode, with the command 'Fullscreen'. The placement needs to be tweaked, but should work.
If you want to use your own model, you can load your own .3dm file in Rhino, then you can right-click on the viewport name, and go to Viewport Layout > Read from File. If you then load my test file, Rhino should open my two viewports, sized correctly, onto your model.
The placement of these viewports need to be tweaked; if you find a better viewport layout, upload an empty Rhino file with your viewports, and we can share eye-layout 'templates'!
5) In Grasshopper, open the .ghx definition. Everything that is multiple-grouped is a value that can be changed. Two things here:
- IPD: Set this and convert it to the proper units for your model.
- Left/right viewport names. In this case, leave this as-is, since you're using my example file.
6) Turn on the Grasshopper Timer, if it isn't on already.
7) In the GH definition, toggle 'SyncEyes' to be True. Then, in the left viewport, try orbiting around with the mouse. The 'RightEye' viewport should move around as well, pretty much simultaneously.
8) In OpenTrack, click 'Start', then toggle 'ReadUDP' to be True. You should see the 'OpenTrackInfo' panel fill with data that's constantly changing.
9) Move around the landscape with your camera, and when you set on a starting view that's ideal, click the triangle of the Data Dam component to 'store' the data.
10) Finally, toggle 'OculusMove' to be true. If all works correctly, both viewports should move based on the Rift's movement.
Let me know if you have any problems!
Cheers,
Dan…
Added by Dan Taeyoung at 11:47pm on December 10, 2013
radiance parameters to get rid of blotching. To add another level of complexity to my problem, I am running simulations with a translucent material with the following properties: void trans testTrans
0
0
7 0.478 0.478 0.478 0.000 0.010 0.178 0.635
I have had no issues with the renderings when I use clear glazing, as seen on this image:
However the blotching-issue becomes very noticeable when I introduce translucent glazing into the scene:
For the two above cases I used the following parameters:
_av_ is set to 0
xScale is set to 2
_ab_ is set to 6
_dc_ is set to 0.5
_aa_ is set to 0.2
_ad_ is set to 2048
_st_ is set to 0.5
yScale is set to 2
_ps_ is set to 4
_ar_ is set to 64
_as_ is set to 2048
_ds_ is set to 0.25
_pt_ is set to 0.1
_dr_ is set to 1
_pj_ is set to 0.9
_dp_ is set to 256
_dt_ is set to 0.25
_lr_ is set to 6
_dj_ is set to 0.5
_lw_ is set to 0.01
I ran another test with increased Radiance parameters and got the following output:
with the following parameters:
_av_ is set to 0
xScale is set to 6
_ab_ is set to 6
_dc_ is set to 0.75
_aa_ is set to 0.1
_ad_ is set to 4096
_st_ is set to 0.15
yScale is set to 6
_ps_ is set to 2
_ar_ is set to 128
_as_ is set to 4096
_ds_ is set to 0.05
_pt_ is set to 0.05
_dr_ is set to 3
_pj_ is set to 0.9
_dp_ is set to 512
_dt_ is set to 0.15
_lr_ is set to 8
_dj_ is set to 0.7
_lw_ is set to 0.005
Although the second blotching case is much better than the first, it is still very bad for hours when the sun is lower in the sky. The above images are rendered for a clear sky at 18:00 in Germany in a West-facing room.
Sorry for the long post! Can someone help? Kind regards, Örn
…
r." I'm sorry to hear that, I take the interface and ease-of-use rather seriously so this sounds like a fundamental failure on my part. On the other hand, Grasshopper isn't supposed to be on a par with most other 3D programs. It is emphatically not meant for manual/direct modelling. If you would normally tackle a problem by drawing geometry by hand, Grasshopper is not (and should never be advertised as) a good alternative."What in other programs is a dialog box, is 8 or 10 components strung together in grasshopper. The wisdom for this I often hear among the grasshopper community is that this allows for parametric design."Grasshopper ships with about 1000 components (rounded to the nearest power of ten). I'm adding more all the time, either because new functionality has been exposed in the Rhino SDK or because a certain component makes a lot of sense to a lot of people. Adding pre-canned components that do the same as '8 or 10 components strung together' for the heck of it will balloon the total number of components everyone has to deal with. If you find yourself using the same 8 to 10 components together all the time, then please mention it on this forum. A lot of the currently existing components have been added because someone asked for it."[...] has a far cleaner and more intuitive interface. So does SolidWorks, Inventor, CATIA, NX, and a bunch of others."Again, GH was not designed to be an alternative to these sort of modellers. I don't like referring to GH as 'parameteric' as that term has been co-opted by relational modellers. I prefer to use 'algorithmic' instead. The idea behind parameteric seems to be that one models by hand, but every click exists within a context, and when the context changes the software figures out where to move the click to. The idea behind algorithmic is that you don't model by hand.This is not to say there is no value in the parametric approach. Obviously it is a winning strategy and many people love to use it. We have considered adding some features to GH that would make manual modelling less of a chore and we would still very much like to do so. However this is such a large chunk of work that we have to be very careful about investing the time. Before I start down this road I want to make sure that the choice I'm making is not 'lame-ass algorithmic modeller with some lame-ass parametrics tacked on' vs. 'kick-ass algorithmic modeller with no parametrics tacked on'.
Visual Programming.I'm not exactly sure I understand your grievance here, but I suspect I agree. The visual part is front and centre at the moment and it should remain there. However we need to improve upon it and at the same time give programmers more tools to achieve what they want.
Context sensitivity."There is no reason a program in 2014 should allow me to make decisions that will not work. For example, if a component input is in all cases incompatible with another component's output, I shouldn't be able to connect them."Unfortunately it's not as simple as that. Whether or not a conversion between two data types makes sense is often dependent on the actual values. If you plug a list of curves into a Line component, none of them may be convertible. Should I therefore not allow this connection to be made? What if there is a single curve that could be converted to a line? What if you want to make the connection now, but only later plan to add some convertible curves to the data? What you made the connection back when it was valid, but now it's no longer valid, wouldn't it be weird if there was a connection you couldn't make again?I've started work on GH2 and one of the first things I'm writing now is the new data-conversion logic. The goal this time around is to not just try and convert type A into type B, but include information about what sort of conversion was needed (straightforward, exotic, far-fetched. etc.) and information regarding why that type was assigned.You are right that under some conditions, we can be sure that a conversion will always fail. For example connecting a Boolean output with a Curve input. But even there my preferred solution is to tell people why that doesn't make sense rather than not allowing it in the first place.
Sliders."I think they should be optional."They are optional."The “N” should turn into the number if set."What if you assign more than one integer? I think I'd rather see a component with inputs 'N', 'P' and 'X' rather than '5', '8' and '35.7', but I concede that is a personal preference."But if I plug it into something that'll only accept a 1, a 2, or a 3, that slider should self set accordingly."Agreed.
Components."Give components a little “+” or a drawer on the bottom or something that by clicking, opens the component into something akin to a dialog box. This should give access to all of the variables in the component. I shouldn't have to r-click on each thing on a component to do all of the settings."I was thinking of just zooming in on a component would eventually provide easier ways to access settings and data."Could some of these items disappear if they are contextually inappropriate or gray out if they're unlikely?"It's almost impossible for me to know whether these things are 'unlikely' in any given situation. There are probably some cases where a suggestion along the lines of "Hey, this component is about to run 40,524 times. It seems like it would make sense to Graft the 'P' input." would be useful.
Integration."Why isn't it just live geometry?"This is an unfortunate side-effect of the way the Rhino SDK was designed. Pumping all my geometry through the Rhino document would severely impact performance and memory usage. It also complicates the matter to an almost impossible degree as any command and plugin running in Rhino now has access to 'my' geometry."Maybe add more Rhino functionality to GH. GH has no 3D offset."That's the plan moving forward. A lot of algorithms in Rhino (Make2D, FilletEdge, Shelling, BlendSrf, the list goes on) are not available as part of the public SDK. The Rhino development team is going to try and rectify this for Rhino6 and beyond. As soon as these functions become available I'll start adding them to GH (provided they make sense of course).On the whole I agree that integration needs a lot of work, and it's work that has to happen on both sides of the isle.
Documentation.Absolutely. Development for GH1 has slowed because I'm now working on GH2. We decided that GH1 is 'feature complete', basically to avoid feature creep. GH2 is a ground-up rewrite so it will take a long time until something is ready for testing. During this time, minor additions and of course bug fixes will be available for GH1, but on a much lower frequency.Documentation is woefully inadequate at present. The primer is being updated (and the new version looks great), but for GH2 we're planning a completely new help system. People have been hired to provide the content. With a bit of luck and a lot of work this will be one of the main selling points of GH2.
2D-ness."I know you'll disagree completely, but I'm sticking to this. How else could an omission like offsetsurf happen?"I don't fully disagree. A lot of geometry is either flat or happens inside surfaces. The reason there's no shelling (I'm assuming that's what you meant, there are two Offset Surface components in GH) is because (a) it's a very new feature in Rhino and doesn't work too well yet and (b) as a result of that isn't available to plugins.
Organisation.Agreed. We need to come up with better ways to organise, document, version, share and simplify GH files. GH1 UI is ok for small projects (<100 components) but can't handle more complexity.
Don't get me wrong, I appreciate the feedback, I really do, but I want to be honest and open about my own plans and where they might conflict with your wishes. Grasshopper is being used far beyond the boundaries of what we expected and it's clear that there are major shortcomings that must be addressed before too long. We didn't get it right with the first version, I don't expect we'll get it completely right with the second version but if we can improve upon the -say- five biggest drawbacks (performance, documentation, organisation, plugin management and no mac version) I'll be a happy puppy.
--
David Rutten
david@mcneel.com…