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…
onstrates the following:
1. The definition's functionality employing HumanUI for the custom user interface.
2. Color based segmentation in manual and auto modes.
3. The evaluation of the definition's ability to handle different point cloud data sets.
This definition performs color based segmentation in two modes.
A manual mode, that implements the Delta-E CIE 2000 color difference formula, for targeted feature detection. An auto mode, that employs a simple RGB Color Range algorithm for quicker preliminary results.
RGB to XYZ to CIELab conversion and Delta-E scripts were based on Colormine's project code from github. Results have been compared and verified with the results of http://colormine.org/color-converter and http://colormine.org/delta-e-calculator/Cie2000.
Each stored class is charted and can be accessed through the UI, as shown at 2:30, where Delta-E CIE 2000, in CieLab color space, output results were found to be in perceptive conformity with human eyes, far superior to the preliminary RGB implementation.
Initial definition versions could process highly subsampled clouds in acceptable timings. Further research showed that employing the multithread processing of Volvox components, bundling the Delta E formula with the RGB to CIE lab color conversion script, per color segmentation calculations for a one million points point cloud would go down from 23 (c# script component) and 8 (vb script component) seconds to approx. 1 second (volvox script cloud component), thus allowing the segmentation of less subsampled point clouds.
I would like to thank Heumann A. and Zwierzycki M. who provided direct support with HumanUI and Volvox. Also Grasshopper3d forum users Maher S. and Segeren P., who contributed with Rhino viewport manipulation scripts.
More on Volvox:
http://papers.cumincad.org/cgi-bin/works/Show?_id=ecaade2016_171&sort=DEFAULT&search=ecaade%20volvox&hits=2629
http://www.food4rhino.com/app/volvox
http://duraark.eu/
HumanUI:
http://www.food4rhino.com/app/human-ui?page=1&ufh=&etx=
ColorMine:
https://github.com/THEjoezack/ColorMine…
giornata inaugurale sarà dedicata alla free-lecture introduttiva finalizzata alla realizzazione di un modello d'architettura complesso attraverso l'utilizzo di comandi e tecniche avanzate di rappresentazione con Grasshopper (plug-in parametrica di Rhinoceros) e 3dsMax. Sarà illustrato inoltre il potenziale di V-ray per 3dsMax realizzando un rendering concettuale. Durante il mini-corso dell' openDAY verranno mostrate le caratteristiche e le potenzialità degli strumenti per far luce sui nuovi valori assunti dalla modellazione 3D. La modellazione 3D sta interessando un pubblico sempre più vasto inserendosi in una nuova fase di ampia disponibilità per conoscenze, software, hardware di prototipazione e modelli. Pur mantenendo tutti i suoi valori già noti la questione si è talmente ampliata fino ad interessare norme giuridiche (diritti sui modelli ,concorrenza con offerte di servizi apparentemente simili, informazioni deformate e onfusione nei media) Makers University[http://www.makersuniversity.com], in collaborazione con parametricart, vi propone un punto di vista ampio e sintetico su queste tematiche.
Al termine della free-lecture, sarà illustrata l'offerta formativa [CLICCA QUI] di parametricart riferita ai corsi che si terranno nei mesi di Gennaio e Febbraio 2013 inseriti all'interno della più ampia programmazione della Makers University. SONO PREVISTE TARIFFE PROMOZIONALI PER COLORO CHE SI ISCRIVERANNO AI CORSI durante l'OpenDAY.
La lezione e la presentazione si terranno nel nuovo spazio co-working il PEDONE.
PROGRAMMAZIONE
- I temi della Makers University [Leo Sorge];
- Modellazione della parametricTower (concept di architettura complessa) utilizzando Grasshopper, applicativo per la modellazione parametrica [VIDEO] [Michele Calvano];
- Modellazione di una copertura reticolare 3D a completamento della parametricTower con 3dsMax utilizzando tecniche di modellazione mesh complesse [Wissam Wahbeh];
- Rendering con V-ray per 3dsMax illustrando la nuova interfaccia nodale [Wissam Wahbeh].
- Question Time per chiarimenti sugli argomenti illustrati.
COME
L'openDAY sarà aperto a tutti gli interessati,completamente gratuito e sarà replicato in tre sessioni di uguali contenuti organizzate nei seguenti orari:
Sessione [1] 11,30 - 13,30
Sessione [2] 15,30 - 17,30
Sessione [3] 17,30 - 19,30
Per necessità di organizzazione è importante la prenotazione all'evento utilizzando il form in fondo alla pagina specificando nella stringa apposita, il nome dell'evento e la sessione (es. open day sessione 1) oltre agli altri dati richiesti.…
he Cordyceps. Maybe some of you find this helpful/useful.
So basically, the Cordyceps is a physical module with 4 knobs and 1 slider. The knobs give an output between 1 and 1000, while the physical slider outputs 0-359. And of course, for this physical module I wrote a plugin to communicate with it. The knobs are intended to be the variables that modifies the design, while the physical slider is intended to be connected to the camera component.
Here I will put up "the recipe" for all to make their own module. You will be able to download the plugin as well.
Please send me a message if you want the 3D-files for the knobs, the box and slider knob. They've been made to directly 3D-print.
Plugin:
https://github.com/zakadjeb/Cordyceps/blob/master/Cordyceps/Cordyce...
Code for Arduino IDE:
https://github.com/zakadjeb/Cordyceps/blob/master/Arduino/_Arduino_...
What you need:
1x - Arduino (Leonardo, UNO or whatever)
4x - Potentiometers
1x - Sliding potentiometer
1x - Breadboard
Bundle of jump wires.
1. So, a potentiometer is a variable resistor, which is basically a component that changes the resistance between the voltage and the ground.
If A is supplied with 5V then B must be connected to Ground. The W will give "read" the resistance, and thus should be placed in Analog input (A0-A5) on the Arduino. The slider potentiometer works the same way.
2. Now connect the 4 pots to each their Analog input. The slider is supposed to be in A4. So to make sure:
A0: Knob1
A1: Knob2
A2: Knob3
A3: Knob4
A4: Slider
3. Now it's time to connect the voltage! Using the breadboard, the voltage can be sent through 1 line, the Ground as well. It should be quite easy to connect them.
4. Now, download the Arduino IDE and copy-paste the code I supplied above. In the IDE, you need to let it know which Arduino you're working with, and which port is should send the script.
5. Almost there. Download the plugin. Open the port you're using through the plugin. Set Start to True and the Cordyceps should be within you.
This recipe will be updated!
Let me know if there are any issues.
// Zakaria Djebbara…
he Cordyceps. Maybe some of you find this helpful/useful.
So basically, the Cordyceps is a physical module with 4 knobs and 1 slider. The knobs give an output between 1 and 1000, while the physical slider outputs 0-359. And of course, for this physical module I wrote a plugin to communicate with it. The knobs are intended to be the variables that modifies the design, while the physical slider is intended to be connected to the camera component.
Here I will put up "the recipe" for all to make their own module. You will be able to download the plugin as well.
Please send me a message if you want the 3D-files for the knobs, the box and slider knob. They've been made to directly 3D-print.
Plugin:
https://github.com/zakadjeb/Cordyceps/blob/master/Cordyceps/Cordyce...
Code for Arduino IDE:
https://github.com/zakadjeb/Cordyceps/blob/master/Arduino/_Arduino_...
What you need:
1x - Arduino (Leonardo, UNO or whatever)
4x - Potentiometers
1x - Sliding potentiometer
1x - Breadboard
Bundle of jump wires.
1. So, a potentiometer is a variable resistor, which is basically a component that changes the resistance between the voltage and the ground.
If A is supplied with 5V then B must be connected to Ground. The W will give "read" the resistance, and thus should be placed in Analog input (A0-A5) on the Arduino. The slider potentiometer works the same way.
2. Now connect the 4 pots to each their Analog input. The slider is supposed to be in A4. So to make sure:
A0: Knob1
A1: Knob2
A2: Knob3
A3: Knob4
A4: Slider
3. Now it's time to connect the voltage! Using the breadboard, the voltage can be sent through 1 line, the Ground as well. It should be quite easy to connect them.
4. Now, download the Arduino IDE and copy-paste the code I supplied above. In the IDE, you need to let it know which Arduino you're working with, and which port is should send the script.
5. Almost there. Download the plugin. Open the port you're using through the plugin. Set Start to True and the Cordyceps should be within you.
This recipe will be updated!
Let me know if there are any issues.
// Zakaria Djebbara…
, presso la sede Manens-Tifs, nei giorni 26,27 e 28 maggio 2016.
Il comfort visivo e la gestione dell’illuminazione naturale in relazione al risparmio energetico diventano sempre più rilevanti per una progettazione innovativa degli edifici. Ad esempio, il nuovo protocollo LEED 4 riconosce crediti per le simulazioni di daylighting e conferma l’importanza degli aspetti progettuali per “collegare gli occupanti con lo spazio esterno, rinforzare i ritmi circadiani, ridurre i consumi di energia elettrica per l’illuminazione artificiale con l’introduzione della luce naturale negli spazi”. Senza strumenti software per la simulazione della luce non è possibile ottenere risultati di qualità. Radiance è un software validato, utilizzato sia a livello di ricerca che dai progettisti ed è tra i più accurati per la simulazione professionale della luce naturale e artificiale. Non ha limiti di complessità geometrica ed è adatto a essere integrato in altri software di calcolo e interfacce grafiche. Queste ultime facilitano le procedure di programmazione. Le principali e più versatili saranno oggetto del corso (DIVA4Rhino e Ladybug+ Honeybee, plug-in per Grasshopper e Rhinoceros 3D).
Il corso è rivolto a progettisti e ricercatori che vogliano acquisire strumenti pratici per la simulazione con Radiance al fine di mettere a punto e verificare le soluzioni più adatte alle proprie esigenze. Sono previste lezioni di teoria e pratica con esempi ed esercitazioni volte a coprire in modo dimostrativo ed interattivo i concetti trattati.
Le domande di iscrizione devono essere presentate entro il 12 maggio 2016.
La brochure con i contenuti del corso e tutte le informazioni sono disponibili su questo link
Il corso è sponsorizzato da Pellinindustrie.…
g-in, brief theory of complex systems, introduction to multi-agent systems and non-linear design, flocking, Boid library, basic examples - brownian motion, adhesion, separation, alignment, geometry following.-----------------------TIME: first session10am – GMT, London11am – Paris, Brussels, Rome, Vienna, Budapest, Bratislava, Warsaw9pm - Sidney7pm – Tokyo6pm – Beijing, Shanghai, Shenzhen, Hong Kong, Taipei3:30pm – Mumbai3pm – Karachi2pm - Samara1pm – Baghdad, Moscow, St Petersburg12pm – Istanbul, Athens, Helsinki, Cairo, JohannesburgTIME: second session3pm – GMT, London4pm – Paris, Brussels, Rome, Vienna, Budapest, Bratislava, Warsaw7pm – Dubai, Abu Dhabi, Baku6:30pm – Tehran6pm – Baghdad, Moscow, St Petersburg5pm – Istanbul, Athens, Helsinki, Cairo, Johannesburg1pm – Rio de Janeiro, São Paulo, Montevideo12pm – Buenos Aires, Santiago10am – Toronto, New York City, Bogota, Lima9am – Mexico City7am – Los AngelesWEBINARSThe rese arch Grasshopper® sessions are unique for their thorough explanation of all the features, which creates a sound foundation for your further individual development or direct use in the practice. The webinars are divided into four groups: Essential, Advanced, Iterative and Architectural. If you are a Rhinoceros 3D or Grasshopper® newcomer, you are advised to take all the Essential sessions before proceeding to the next level. If none of the proposed topics suit your needs or if you require special treatment, you can request a custom-tailored 1on1 session. All sessions are held entirely in English.The webinars are series of on-line live courses for people all over the world. The tutor broadcasts the screen of his computer along with his voice to the connected spectators who can ask questions and comment in real time. This makes webinars similar to live workshops and superior to tutorials.…
Added by Jan Pernecky at 3:36pm on February 17, 2015
ally to describe a process of repeating objects in a self-similar way. Simply stated, the definition of a recursive function includes the function itself. Fractals are among the canonical examples of recursion in mathematics and programming. A loop can simply be a way to apply the same operation to a list of elements, but it is an iterative loop if the results from one step are used in the calculation of the next step. In design research controlling recursion becomes a new strategy to define new forms and spaces.
BRIEF
In this workshop we will be exploring iterative strategies through parametric design. Main tool for the course will be grasshopper3d and its add-on Anemone. Anemone is a simple but effective plug-in for Grasshopper that enables for loops in a simple and linear way. We will explore several strategies such iterative growth, L systems, fractals, recursive subdivisions and more. Our course will focus on how those methods can affect three-dimensional geometries, generating unexpected conformations.
TOPICS
intro to rhinointro to grasshopperadvanced grasshopperdata managementintro to loopscellular automatal-systemsagent based modelling
SCHEDULE
Day 1 / friday 16:00Tour Green Fab LabBasics of 3D modeling in RhinocerosBasics of GrasshopperOpen Lecture by Jan Pernecky, founder of rese arch
Day 2 / saturday 10 am- 18 pmRecursive iterative methodsAdvanced Topics of looping
Day 3 / sunday 10 am – 18 pmRecursive iterative methodsFinal presentation session
REQUIREMENTS
The workshop is open to all participants, no previous knowledge of Rhinoceros and Grasshopper is required (although an introductory knowledge is welcome). Participants should bring their own laptop with a pre-installed software. The software package needed has no additional cost for the participant (Rhino can be downloaded as evaluation version, Grasshopper and plugins are free). These softwares are subject to frequent updates, so a download link to the version used in the workshop will be sent to the participants a few days before the workshop.…
Added by Aldo Sollazzo at 11:10am on October 6, 2015
instead of ballooning outwards, just puffing upwards.
THIS WILL WORK! Creating the mesh springs is only three seconds for 200X200 and the Unary Force is still milliseconds. Only Kangaroo takes an initiation time then cycles rapidly (0.5 seconds each) and it only takes a few cycles, maybe a dozen or two.
There is considerable 3D aliasing from the 2D mesh crudeness.
Now, to best Laurent's scheme, let's double down to 400X400. First I disable Kangaroo, and the timer. The preparation takes...FOREVER....and...ever...4.6 minutes to cull the points is all, a trivial step there is likely a better strategy for than finding the ones on the inside then using those to cull duplicates from the whole collection. The springs only took 12 seconds and the forces again milliseconds.
Kangaroo, to initialize takes...after hitting the reset button to start it...over 15 minutes and counting...well 400X400 is 160K vertices and Rhino tends to bog down at 30K points...but it was done in 30 minutes. Then I enable the timer and each cycle takes...uh...it's not in any error mode but nothing is happening past a very faint first automatic cycle that shows in the mesh...yet no CPU power is being used by Rhino...well...it's simply not running...ah, well, there's just a dummy delay of another 5 minutes and then the cycles take 2.7 seconds...what a stupid delay that was not using CPU power.
Now that it's cycling, can I change the stiffness in real time, usually I can...well, no, I seem to be back in the 5 minute delay, but not the 30 minutes interface-locking one...still waiting. Here is a 1/4 scale height model of the above output:
Time's up, life goes on. The aliasing and slow speed make it unworkable except for little logos or something. Some math and parallel processing are needed?
…
Added by Nik Willmore at 5:51pm on February 21, 2016