RfM - Python Rifs Getting Started 2

RfM
Python Rifs Getting Started 2

Introduction

This tutorial is an extension of the tutorial "Python Rifs Getting Started 1". The reader should carefully follow that tutorial before following the instructions shown on this page.

Using the Vertex Data to Place a "Cluster" of Points

Select both polymesh surfaces in Maya and execute the following MEL procedure in the Add_Primvar tab of the script editor.

addFloatPrimVar("render_mode", 1);

Save the following script shown in listing 5 as rif_mesh_geo5.py and edit the Rif_Py tab - as shown below. Note the use of the rif_mesh_geo5.Rif(200, 0.3, 0.02).

import batch
import rif_mesh_geo5
reload(rif_mesh_geo5)
rifs = ['rif_it','rif_mesh_geo5.Rif(250, 0.3, 0.02)' ]
batch.render(1,1, rifs)

Listing 5 - rif_mesh_geo5.py

import prman
from rif_utilities import MeshDB
from rif_utilities import getFloatPrimvar
from rif_utilities import genPointsAroundVertex
class Rif(prman.Rif):
    MESH = 0
    POINTS = 1
    POINTS_AND_MESH = 2
    DEFAULT_MODE = MESH
    
    def __init__(self, ri, num, rad, width):    
        prman.Rif.__init__(self, ri)
        self.num = num      # number of points clustered per vertex
        self.rad = rad      # radius of each cluster
        self.width = width  # the size of the points in each cluster
  
    def PointsGeneralPolygons(self, nloops, nverts, verts, params):
        ##___________________________________
        render_mode = int(getFloatPrimvar('render_mode', params, Rif.DEFAULT_MODE))
        if render_mode == Rif.MESH:
            self.m_ri.PointsGeneralPolygons(nloops, nverts, verts, params)
            return
        mesh = MeshDB(nloops, nverts, verts, params)
        vertices = mesh.getVertices()
        vert_counter = 0
        for vert in vertices:
            extra_points = genPointsAroundVertex(self.num, vert, self.rad, vert_counter)
            points_params = { 
                         prman.Ri.P : extra_points, 
                         prman.Ri.CONSTANTWIDTH : self.width 
                        }    
            self.m_ri.Points(points_params)
            vert_counter += 1
        
        if render_mode == Rif.POINTS_AND_MESH:
            self.m_ri.PointsGeneralPolygons(nloops, nverts, verts, params)
         ##___________________________________

Using the new rif should produce an image similar to figure 5.

Figure 5

Using the Vertex Data to Place a Curve around each Face

Save the following script shown in listing 6 as rif_mesh_geo6.py and edit the Rif_Py tab - as shown below. Note the use of the rif_mesh_geo6.Rif(0.05).

import batch
import rif_mesh_geo6
reload(rif_mesh_geo6)
rifs = ['rif_it','rif_mesh_geo6.Rif(0.05)' ]
batch.render(1,1, rifs)

Listing 6 - rif_mesh_geo6.py

import prman
from rif_utilities import MeshDB
from rif_utilities import getFloatPrimvar
  
class Rif(prman.Rif):
    MESH = 0
    CURVES = 1
    CURVES_AND_MESH = 2
    DEFAULT_MODE = MESH
    
    def __init__(self, ri, width):    
        prman.Rif.__init__(self, ri)
        self.width = width
                   
    def PointsGeneralPolygons(self, nloops, nverts, verts, params):
        ##___________________________________
        render_mode = int(getFloatPrimvar('render_mode', params, Rif.DEFAULT_MODE))
        if render_mode == Rif.MESH:
            self.m_ri.PointsGeneralPolygons(nloops, nverts, verts, params)
            return
        
        mesh = MeshDB(nloops, nverts, verts, params)
        curves_verts = mesh.getAllLoops()    
        curves_params = {prman.Ri.P : curves_verts, 
                              prman.Ri.CONSTANTWIDTH : self.width
                            }    
        self.m_ri.Curves(prman.Ri.LINEAR, nverts, prman.Ri.PERIODIC, curves_params)
        if render_mode == Rif.CURVES_AND_MESH:
            self.m_ri.PointsGeneralPolygons(nloops, nverts, verts, params)
         ##___________________________________

Using the new rif should produce an image similar to figure 6.

Figure 6

Using the Vertex Data to Place a Curve at each Vertex Normal

Save the following script shown in listing 7 as rif_mesh_geo7.py and edit the Rif_Py tab - as shown below. Note the use of the rif_mesh_geo6.Rif(0.05).

import batch
import rif_mesh_geo7
reload(rif_mesh_geo7)
rifs = ['rif_it','rif_mesh_geo7.Rif(1, 0.05)' ]
batch.render(1,1, rifs)

Listing 7 - rif_mesh_geo7.py

import prman
from rif_utilities import MeshDB
from rif_utilities import getFloatPrimvar
  
class Rif(prman.Rif):
    MESH = 0
    NORMALS = 1
    NORMALS_AND_MESH = 2
    DEFAULT_MODE = MESH
    
    def __init__(self, ri, length, width):    
        prman.Rif.__init__(self, ri)
        self.length = float(length)     # length of each line representing a normal
        self.width = width           # diameter of each line
                   
    def PointsGeneralPolygons(self, nloops, nverts, verts, params):
        ##___________________________________
        render_mode = int(getFloatPrimvar('render_mode', params, Rif.DEFAULT_MODE))
        if render_mode == Rif.MESH:
            self.m_ri.PointsGeneralPolygons(nloops, nverts, verts, params)
            return
        
        verts_per_curve = []  # 2 verts per normal - base and tip
        curves_verts = []     # list of base and tip vertex coordinates
        mesh = MeshDB(nloops, nverts, verts, params)
        vertices = mesh.getVertices()
        for vert in vertices:    
            vx,vy,vz = vert
            nx,ny,nz = mesh.getAveNormal(vert)
            curves_verts.extend(vert) # coordinates of the base of a normal
            curves_verts.extend( [vx + nx * self.length, 
                                vy + ny * self.length, 
                                vz + nz * self.length] ) # ditto the tip
            verts_per_curve.append(2)
                
        curves_params = {prman.Ri.P : curves_verts, 
                         prman.Ri.CONSTANTWIDTH : self.width
                        }    
        self.m_ri.Curves(prman.Ri.LINEAR, verts_per_curve, prman.Ri.NONPERIODIC, curves_params)
        if render_mode == Rif.NORMALS_AND_MESH:
            self.m_ri.PointsGeneralPolygons(nloops, nverts, verts, params)
         ##___________________________________

Using the new rif should produce an image similar to figure 7.

Figure 7