CGA Code for Street Network

Question

Hello CE Community!
Through ArcGIS Desktop I have separated the Road Network into:
 1) Main Road 
2) Substitute Road 
3) Only for pedestrians. 
Also I have the Building Blocks. 
I would like to ask what code do I need to write, in order the Street Net to be presented presented in 3D shape.
Thank you!

DavidWasserman · Answer

Hi Nikos, From a GIS perspective, the short answer is CE preserves these attributes but does not intrinsically know what to do with them. You can make or modify a rule to visualize street based on your research categories (as Cheryl suggested), but you can also select those streets that match a specific category and color code them/change them per that category. I usually do this when making batch edits based on functional classification (similar to what you are doing now). For example, if you have a bunch of streets in a "traffic calming" category as your streets get closer to a school, then maybe you select every street in that category and add high visibility crosswalks and narrow the lane widths. Or you just set their color to something unique for visualization purposes. How detailed do you want your streets to be? If you have street widths/lanes information it makes sense to provide that information in a form that matches the street object/rule attributes you are using. This makes them automatically map to the rule of interest on import. # -------------------------------- # Name: CESelectLayerByAttribute.py # Purpose: Select an object by an attribute in CityEngine. # Current Owner: David Wasserman # Last Modified: 12/22/2015 # Copyright: (c) Co-Adaptive # CityEngine Vs: 2015.2 # Python Version: 2.7 # License # Copyright 2016 David J. Wasserman # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # -------------------------------- # Import Modules from scripting import * # get a CityEngine instance ce = CE() # Declare variables fieldName = "Crosswalk_End" fieldValue = "ladder" # Main Function def selectObjByAttribute(attr, value): layers = ce.getObjectsFrom(ce.scene, ce.isLayer) print( "There are " + str(len(layers) - 2) + " layers in the current scene.") # -2 To remove Panorama and Scene Light counter = 0 print("Iterating through all layers") print("Collecting objects from scene.") selectedLayers = [] # Selection is an empty list to hold all our slection for layer in layers: # for loop iterates through all objects in scene print("Checking objects in layer ", layer) objectList = ce.getObjectsFrom(layer) for object in objectList: attrvalue = ce.getAttribute(object, attr) # attrvalue gets assigned to it a retrieved attribute print("The current layer is:", layer) if attrvalue == value: # if the attribute equals our value selectedLayers.append(layer) # append the attribute value pair to the list selection print("Matched Attribute at value", value, " layer Added to selection.") break ce.setSelection(selectedLayers) # set the selection equal to the list we just made ce.waitForUIIdle() if __name__ == '__main__': selectObjByAttribute(fieldName, fieldValue) pass‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

CherylLau · Answer

I'm not sure what the capabilities of ArcMap are, but if you can export your data so that you can store an object attribute that marks a shape as being in a certain category, then you can write a rule that connects to this attribute and behaves accordingly.  For example, if each shape has an object attribute called category, you can write a rule that has an attribute also called category and then link this rule attribute to the object attribute in the inspector (Inspector -> drop down arrow next to rule attribute -> Connect Attribute -> Object Attribute).  Then, to visualize the streets based by their categories, in your rule you can color the streets based on category, for example.

NikosTziokas · Answer

Thank you all for your replies. However I have just figured out that I have to work in a different way.
I have got the Primary Schools and the Street Network of a city in a .shp file type. Each Road leads to a specific school (this was primarily the way to categorize the Street Network). Therefore 2 research questions are arising:
1) Does CE provide the possibility of visualization of the Street Network based on the afforementioned categories?
2) If so, how can I visualize those categories in the 3D Street Network view?
I have used  ArcMap software to split the Street Network in categories. After that I have uploaded the .shp file in CE.
My first thought is to visualize the Street Network ( I do not have to define the Traffic Lanes). I also have measured the Width & Length of the Roads. Does CE keep the categories being defined in ArcMap during the visualization progress?