Hello Blender Wizards!

I am seeking your help in trying to solve a GIS problem using Blender. Any help, pointers or general discussion related to this will be highly appreciated.

I am a Blender n00b but I am aware that Blender has a GIS plugin that helps in creating cityscapes by capturing terrain, buildings etc. from GIS maps. Suppose a city with 3D buildings, parks, lakes has been created. Now, I need to find all dwelling units from which a particular park/lake is visible.

GIS has something called a viewshed analysis which can be used to find area which will be visible from any given point. But that is the limitation, it just gives the view from a point, not a whole area.

My idea is to create stack dwelling units (apartments in high rises) as white objects having unique Object IDs in Blender and parks/lakes as colored light sources. Upon rendering, it is easy to see what dwelling units are lit up in which color. That is all good for visual analysis.

My question is, is there any way in Blender to get Object IDs of Objects that have non-white colors on their face? Or do I have to take the help of a Gaming Engine for this?

Looking forward to the responses. Cheers!

  • DontNoodles@discuss.tchncs.deOP
    1·
    1 year ago

    Thank you for taking the time to try it out. For now just finding of any part of the building can see any part of the park should suffice.

    As I mentioned in one of my other replies, I’m mainly a GIS person and a Blender n00b even though I’ve been calling myself that for a couple years now.

    I saw some videos on geometry nodes and raycast nodes and my faith in Blender as a solution to the problem has become stronger. I’d never really seen the spreadsheets in Blender and mention of attributes makes me wonder if it is the same concept as in GIS where each feature (like object in Blender) has some properties associated with it. I have some exposure to Python, though not as part of Blender.

    I think that a good academic paper and a tool could be developed out of it and it has underscored my conviction that the divide between gaming related tools and GIS is at the cusp of merging.

    Maybe this will serve as my motivation to learn Blender though I want to skip the unnecessary parts for now and just want to learn stuff that will help me learn and tackle this problem. Maybe you could give me a broad roadmap of what to learn.

    Also, please share a minimum working example of the thing that you tried if possible. If you are able to experiment further, I’ll be delighted to learn.

    Thanks again.