How to addIndices after added serveral vertex

[leon.dong]

My code is like below. 

Unigine::MeshPtr myUnigineMesh = Unigine::Mesh::create();
for(int i=0;i<100;i++)
{
myUnigineMesh->addVertex(Unigine::Math::vec3(pos.x, pos.y, pos.z), surfaceIndex);
}

The vertex info have been added successfully. My question is how to add Index like sample code which in your offical doc.

                        myUnigineMesh->addIndex(0, surfaceIndex);
                        myUnigineMesh->addIndex(1, surfaceIndex);
                        myUnigineMesh->addIndex(2, surfaceIndex);

                        myUnigineMesh->addIndex(3, surfaceIndex);
                        myUnigineMesh->addIndex(2, surfaceIndex);
                        myUnigineMesh->addIndex(1, surfaceIndex);

 

I can run the sample code successfully. Since the sample code only have 4 vertex , however my scenario has more than 10 vertex , is there any easy way to automatically calculate the index or indices info? 

Simply searched doc no useful, so looking forward to help from forum.

Thanks for any advice.

Edited December 6, 2023 by leon.dong

[leon.dong]

Or does Unigine has some methods to auto generte the index info depend on these vertext info ?

 

[silent]

You can call Mesh::createIndices() to generate indices automatically. Something like that:

Unigine::MeshPtr m = Unigine::Mesh::create();
int s = m->addSurface("surface");

m->addVertex(Unigine::Math::vec3(0.0f, 0.0f, 0.0f), s);
m->addVertex(Unigine::Math::vec3(1.0f, 1.0f, 0.0f), s);
m->addVertex(Unigine::Math::vec3(0.0f, 1.0f, 0.0f), s);

m->addVertex(Unigine::Math::vec3(0.0f, 0.0f, 0.0f), s);
m->addVertex(Unigine::Math::vec3(1.0f, 0.0f, 0.0f), s);
m->addVertex(Unigine::Math::vec3(1.0f, 1.0f, 0.0f), s);

m->createIndices();
m->createTangents();
m->createBounds();

 

[leon.dong]

Thanks silent. very helpful.

I checked my codes and data. the difference is , your sample code can run since the vertext info is the pattern of forming triangles

However my vertex information is a geometry edge vertex information , so call createIndices will crash.

Is there any solution for that kind of vertex ?

Thanks again.

[silent]

Unfortunately, createIndices()can only create them if you provide vertices in a specific format (as shown in previous message).

[leon.dong]

I tried below method, it could help a lot . 

 void A::GetNewVertices(std::vector<Unigine::Math::vec3> inVertex, std::vector<Unigine::Math::vec3>& outVertex)
    {

        //input pos
        std::vector<KernelTest::Point_3> points;
        for (size_t i = 0; i < inVertex.size(); i++)
        {
            points.push_back(KernelTest::Point_3(inVertex[i].x, inVertex[i].y, inVertex[i].z));
        }

        //
        Delaunay3D deTriangles(points.begin(), points.end());

        ////
        for (Delaunay3D::Finite_facets_iterator fit = deTriangles.finite_facets_begin(); fit != deTriangles.finite_facets_end(); ++fit)
        {
            Delaunay3D::Facet face = *fit;
            
            std::cout << deTriangles.triangle(face) << std::endl;

            //
            KernelTest::Point_3 p1 = face.first->vertex((face.second + 1) % 4)->point();
            KernelTest::Point_3 p2 = face.first->vertex((face.second + 2) % 4)->point();
            KernelTest::Point_3 p3 = face.first->vertex((face.second + 3) % 4)->point();
					  //output 
            outVertex.push_back(Unigine::Math::vec3(p1.x(), p1.y(), p1.z()));
            outVertex.push_back(Unigine::Math::vec3(p2.x(), p2.y(), p2.z()));
            outVertex.push_back(Unigine::Math::vec3(p3.x(), p3.y(), p3.z()));
        }

    }

[leon.dong]

Is Unigine clockwise or anti-clockwise  when add vertex to surface ?

[silent]

Yes, counter-clockwise is expected vertex order in surfaces of the mesh.

[leon.dong]

Thanks silent.

very efficient.

Edited December 11, 2023 by leon.dong