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How are point clouds used?

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I am about to upgrade the entirety of my work-in-progress universe creation game, and it seems that the best way for me to move forward is by shifting everything to point clouds, instead of my current polygonal approach. Does anyone have some good online literature or (even better) videos that I could learn more about point clouds with??

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A point cloud is just... a lot of points. So it's not clear what exactly you're asking for here. Normally a point cloud comes from data you extract from a real-world source, but then you convert it to polygons or similar so that you can actually show it.

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A point cloud is just... a lot of points. So it's not clear what exactly you're asking for here. Normally a point cloud comes from data you extract from a real-world source, but then you convert it to polygons or similar so that you can actually show it.

That's basically what I'm asking about: What are they used for, and how do people do those things with them? I am -completely- new to point clouds, so I am basically just shouting "What is this?! Why? HOW??" from the top of my lunges, to get a starting point. Everything online seems to only show off pretty pictures (very pretty, though), not talk about the technical side of using point clouds...

That.... is a lot of stuff. Is there anything specific in it you are thinking of? I will be digging through as much as possible, but if you have any specific pointers, I am all ears/eyes!

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It sounds like you are referring to some specific uses of point clouds that you have seen and felt are applicable to what you want to do, but just saying "point clouds" doesn't tell us what they are, because point clouds are a much simpler concept. What is it you've seen, and why do you think it's relevant to your work?

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for a game you most likely do not want to go down that road. there are reasons others aren't using them in games. i work with point-cloud data (work-work, not game-work).

- needs LOTS of diskspace

- needs LOTS of memory

- needs LOTS of processing power

- needs LOTS of optimization to be used in real-time

- needs intermediary spatially-indexed format to be displayed in real-time.

- animation/simulation basically needs HPC and probably won't be possible real-time.

not much point (ha!) to it when it comes to games really. sure there are fancy demos of physical effects in real-time, but they are just that - fancy demos.

you would probably end up optimizing the data-structures to a point where they essentially resemble polygons/voxels/not-point-clouds anyway.

Edited by ninnghazad

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The first question you should ask yourself is why do you think points clouds is the complete solution? To answer that question you and only you can do the cost-benefit analysis as no one else knows your use case. A part of that is knowing how the chosen tech works in-depth, again no one can tell you how, they can just point you to resources. I'm saying this because you mention this.

That.... is a lot of stuff. Is there anything specific in it you are thinking of? I will be digging through as much as possible, but if you have any specific pointers, I am all ears/eyes!


Seems like you are expecting specific help when the only one who knows the use case is you.

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it seems that the best way for me to move forward is by shifting everything to point clouds, instead of my current polygonal approach.
...
What are they used for, and how do people do those things with them? I am -completely- new to point clouds, so I am basically just shouting "What is this?! Why? HOW??" from the top of my lunges, to get a starting point. Everything online seems to only show off pretty pictures (very pretty, though), not talk about the technical side of using point clouds...

How did you come to decide that they're the best solution to your problem if you don't yet know much about them? :)

That.... is a lot of stuff. Is there anything specific in it you are thinking of? I will be digging through as much as possible, but if you have any specific pointers, I am all ears/eyes!

That's one of the only games know of that uses a point cloud renderer. That whole presentation is a gold mine for anyone wanting to do the same thing. Note how damn complicated their various approaches are though...


Point clouds are used in the art-creation stage of many games. Photogrammetry software like Reality Capture or Photoscan can turn a dozen photographs of an object into a 3D point cloud of that object. Laser scanners (LIDAR) can also be used to produce point clouds of real objects. These are then processed into many-million polygon objects, which artists then use to create low-poly game assets.
That's all just art software magic though - the end result is still polygons and texture maps.

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@Kylotan: I haven't seen anyone use it for anything related to what I am working on, actually. I am doing some procedurally generated landscape stuff, based on real-world science (my blog), and polygons no longer offer the sufficient flexibility for having forces affect the landscape. Point clouds seem(!!) to offer the possibility of having landscapes be carved by erosion, twisted by tectonic activity, and such. Most of all, I am hoping to cmopare point cloud methods to my previous polygon methods, to see which is best at what tasks. But my knowledge of point clouds is still at square one...

@ninnghazad: Yeah, my problem is that I keep finding point clouds used for things like survey data and big 3D scans, and not from an angle that actually sets the point cloud on its own. I get the feel, including from your post, that point clouds simply have not (yet?) found a role outside analytical and visualization uses, is that about right?

@cgrant: You're kind of right. The problem is that I lack a place to start down that road to cost-benefit analysis and specific evaluations. I simply have never encountered point clouds used outside of scanning and visualization before, but I was getting the feel that with the growth in voxel use, point clouds were being used more in other fields. I get the feeling I assumed wrong?

@Hodgman: I just noted the video at the bottom, I was actually going through every part of the website one by one. Now, it makes a lot more sense, and I got a TON of stuff out of the video alone, thanks!! I never decided point clouds are the best solution, I am trying them out because they offer some (non-graphics related) options that are really not that great with polygons (morphing surfaces, in a nutshell). What I now feel even more than before I watched the video is that, assuming one is willing to adapt one's art style to the tech, there are a lot of neat options in using point clouds straight, rather than converting to polygons (which was my original thought, and may still play a part). There is no question of mine in that, just an observation and ideas. Feel free to comment, though!

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Landscape erosion and similar is usually modelled by using height maps. Only once the calculations are finished would this be converted into polygons for eventual display. I don't know how well it would adapt to tectonic plate simulation. I suppose that if each sample on a height map had an x/y position that could be moved laterally, you can view that as a point cloud. But if you join them up, then you just have a standard polygonal system too. It's all just a bunch of 3D positions, just different ways of presenting them.

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