Mannually set hair root [SOLVED]
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On 03/01/2017 at 11:25, xxxxxxxx wrote:
Is there a way for setting manually guide to and polygon id? I know I can do it automaticly with root => set root but that not allow me do to a very presize work.
Moreover is there a way for generate very precise hair (I guess saying each vertex of each hair)? For the moment the only solution I have found is to draw guide and generate hair as guide which is really not optimized for animation purpose.
Just a preview here is in 3ds max rendered with vray, generated with ornatrix
http://img15.hostingpics.net/pics/857158ornatrix3ds.jpgAnd here the file exported as oxh(ornatrix export format) in c4d render with arnold / default alshader and skydome using each hair as guide and then doing a root => set root. But as said it's very not suitable for animation I would really love to be able to do create a hair in polygonID xx and then set his parented root to rootID xx.
http://img15.hostingpics.net/pics/411830ornatrixcad.jpgAgain I'm not sticky to python. But I would prefer.
And happy new year to every one have a nice year with a lot of plugins !Thanks in advance
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On 06/01/2017 at 14:12, xxxxxxxx wrote:
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Hi gr4ph0s, thanks for writing us.
I've investigated your question and looking between the HairGuides() and the HairObject() classes I might have found something useful for your needs. I actually suggest you to have a look at the Cinema 4D SDK Hair Generator example which might give you some hints where to look for.
In addition find a short snippet below showing how to create hair from scratch on a generic PolygonObject at its vertices.
At the moment the code is in C++ since on Python it seems there are some issue I still need to address.Best, Riccardo
if (!doc) return false; Int32 hairSegs = 12; Int32 hairCount = 1000; // get the selected object BaseObject* activeObj = doc->GetActiveObject(); if (!activeObj || !activeObj->IsInstanceOf(Opolygon)) return true; // cast to HairObject HairObject* hairObj = HairObject::Alloc(); if (!hairObj) return true; BaseContainer* hairBC = hairObj->GetDataInstance(); if (hairBC) { hairBC->SetLink(HAIRSTYLE_LINK,(C4DAtomGoal* ) activeObj); hairBC->SetInt32(HAIRSTYLE_HAIR_COUNT, hairCount); } // create material BaseMaterial* hairMat = BaseMaterial::Alloc(Mhair); doc->InsertMaterial(hairMat); // create the texture tag and assign to hair object TextureTag* ttag = TextureTag::Alloc(); ttag->SetMaterial(hairMat); hairObj->InsertTag(ttag); // get some information to build the new hair guides PolygonObject* activePolyObj = ToPoly(activeObj); const Vector* activePolyPoints = activePolyObj->GetPointR(); const CPolygon* activePolyPolygons = activePolyObj->GetPolygonR(); Int32 activePolyPolygonsCnt = activePolyObj->GetPolygonCount(); Int32 activePolyPointsCnt = activePolyObj->GetPointCount(); // define the hair segs and allocate the guide HairGuides* customHairGuide = HairGuides::Alloc(activePolyPointsCnt, hairSegs); if (!customHairGuide) return false; // retrieve the pointer to the new guides points Vector* customHairGuidePoints = customHairGuide->GetPoints(); Int32 customHairGuideGuidePointsCnt = customHairGuide->GetGuidePointCount(); Random rng; rng.Init(SAFEINT32(GeGetMilliSeconds()/1000)); // create a guide at each vertex of the root object for (Int32 i = 0; i < activePolyPolygonsCnt; i++) { CPolygon poly = activePolyPolygons[i]; Int32 vtxCnt = poly.IsTriangle() ? 3 : 4; for (Int32 k = 0; k < vtxCnt; k++) { Vector pos = activePolyPoints[poly.GetPoint(k)]; HairRootData rootData; rootData.m_ID = poly.GetPoint(k); rootData.m_Type = HAIR_ROOT_TYPE_VERTEX; rootData.m_N = CalcFaceNormal(activePolyPoints, poly); rootData.m_P = pos; // increase y and add some noise to x and z at each point of the hair guide for (Int32 j = 0; j < customHairGuideGuidePointsCnt; j++) { pos.x += j*2*rng.Get11(); pos.y += j*3; pos.z += j*2*rng.Get11(); customHairGuidePoints[poly.GetPoint(k) * customHairGuideGuidePointsCnt + j] = pos; // set the hair root if (customHairGuide->GetRoot(poly.GetPoint(k)).m_Type == -1) customHairGuide->SetRoot(poly.GetPoint(k), rootData, false); } } } // set the new hair guide hairObj->SetGuides(customHairGuide, false); // update the hair object hairObj->Update(doc); // add the hair object to the scene doc->InsertObject(hairObj, nullptr, nullptr); EventAdd(); return true;
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On 06/01/2017 at 15:33, xxxxxxxx wrote:
Firstly thanks you for your exemple.
I got few questions about it.
- For root placement ornatrix use thoses structures
struct OrnaExpRootTM { float tm[4][3]; ///< 4x3 transform matrix relative to object space }; struct OrnaExpSurfDep { unsigned long face; ///< index into mesh face array: face this root is placed on float barycentricCoordinate[3]; ///< barycentric coordinates of this root on face };
> So for simulating this I need to understand a bit more clearly HairRootData parameters.
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> m_ID, is the root id?
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> m_Type (in my case it will be HAIR_ROOT_TYPE_POLY)
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> m_S / m_T I acutually don't know thoses utilities.
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> m_P is the position. But global position? relative to the object? Relative to polygon?
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> m_N is the normal.
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> 2. Maybe it was not clear in my previous post but is it possible to make something like my screenshot. http://img11.hostingpics.net/pics/661554hair.jpg
> 1 guide (which is placed where I want regarding my first ask and xx hairs linked to the guide (so to the polygon?) which are placed / lined as I want (doing like you have done in your script but instead for doing it for the guide, doing it for each hairs).
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> Regarding the SDK it seem to not be possible since I was unable to find class related to hair but about the hairObject.
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> 3. I don't really understand the function of SetGuide what this function really do
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And another ask a litlle bit out of context.
It might be stupid but for executing your code I have register a command plugin is there another way to run C++ directly on the fly? (think not since it's a compilated language but that cost nothing to ask :p)Anyway thanks you alot for all the informations I understand a bit more how hair are managed by c4d for now (before I always missunderstand root / guide / hair).
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On 10/01/2017 at 06:40, xxxxxxxx wrote:
Hi gr4ph0s, thanks for providing your further comments.
With reference to your question, i prefer to answer point-by-point:
1)- m_ID is the id of the geometrical element the root is bind to: in case of a guide rooted on a polygon it's the polygon index of the face used to let the guide grow, in case of a guide rooted on a vertex is the vertex index
- m_Type is the type of root you'r going to use: check the available values here
- m_S / m_T are the s and t parametric coordinates used to locate the guide on a polygon: if you have a face you're allowed by specifying those two values where the guide is effectively located on that polygonal face; these two values are useless when guides are rooted to a vertex
- m_P is the root position, it's normally expressed in local coordinates with respect to the object; consider that this data is not required when m_S /m_T are specified on guide rooted to a polygon (m_type == HAIR_ROOT_TYPE_POLY)
- m_N is the root normal;
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yes it's indeed possible, simply define one single guide rooted on the polygon, set the number of hair to the desired number and you're done;
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the SetGuide() method is used to set the guides you want your hair object to use: as you can see in my example i allocate an HairObject, then i allocate an HairGuides object, then i specify the points of the guides and in the end, by using the SetGuide() method, I set my HairObject object to create hair based on my HairGuides object just created;
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no it's not possible. C++ is a compiled language which can't be executed as an interpreted language in a on-the-fly fashion.
Best, Riccardo
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On 11/01/2017 at 02:16, xxxxxxxx wrote:
Thanks you Riccardo for all the informations.
If I still got some questions I will open new thread in C++ section.