3D models look awful, what am I doing wrong?

General Discussion
1

I am using a phantom 4 pro. The 2d maps look fine but the 3D maps are all mangled and warped, in some cases a wall is missing and it looks like you can see through the house. First I flew at 66 feet, then I flew at about 130. Same result. The home is in a neighborhood with other home close by. I must be doing something wrong, but I have tried several times and with other software I am not having this issue. We are using the trial version and this will be the determining factor. The file is 4744 ATT 3. I am viewing on a new very high speed iMac

2

Hi RaptorPilot,

Without seeing the 3D model, or the pre processing data i can give you some best practice tips for increasing the initial level of quality, and resolution that your 3d maps have.

Always run test flights!!! cant stress this practice enough, it comes down to measure twice cut once; make sure you are finding the best settings for your goals.

  1. Fly High - usually over 200 ft is a good starting point, fly a test flight at this height see how the data looks, and than adjust from their. It may seem counter intuitive but in general the higher you fly the better the result will be. This is due to the fact that flying higher will give each photo more data contained in it, that will mean the processing software will have more data to create accurate tie points in a larger quantity. The more tie points the better the ability for the software to determine points in the sparse and dense clouds.

  2. Fly Multiple Rounds - One plan will not be enough to create highly detailed models, especially if those models have details, overhangs, and other unique features. I generally fly at least two tiers and usually three when i am mapping with the 3D model as a targeted producible. First fly a mission over the entire area with the camera set straight down, as you might for a 2d ortho. Next you will want to capture some oblique (lower alt but with greater camera angle) this will let you capture details from the sides (an orbit path does quite fine, or you can fly manually) make sure that you dont get too much horizon in these as that can make the tie point processes less accurate. Third i fly a lower mission with the camera almost straight on, especially if the target being mapped has a lot of detail this will help.

  3. Ensure a good level of side, and overlap on all tiers of your flights. There is a balance here between detail, and diminishing returns (eventually with say 99% overlap you will see less return as the number of photos increases but the new data in them does not)

  4. Time Of Day and conditions - Shadows are generally not good for your accuracy, so shooting very early or very late when shadows tend to be the longest will usually give poorer quality results. i try to shoot around mid day and overcast conditions help minimize the effects of shadows as well.

Post process - even with the settigns correct, the perfect light conditions and multiple tiered flights, the 3d models will not be perfect, you may have to put them into a CAD, or modeling program to close gaps, or tweak the model (especially if a goal is 3d printing)

Hope this helps!!!

please show us your maps!

3

@RemotelyPossible Hi Scott, I am looking for answers on how to do the “side” flight autonomously. I can fly the first fight as “2d ortho” using DroneDeploy app. Now, I can simply click the “3D” option so DD takes the angled shots. So…what about the 2 additional shots that DD recomends? How do I do them auto-magically?

And it sounds like the altitude should be lower (175ft AGL) or lowest possible? Thanks.

4

Hi @JamesChung, have you looked over our support documents about 3D models? Here is our guide to making successful 3D models in DroneDeploy—the capturing oblique imagery during flight section might have some of the answers you’re looking for! If you are still having issues after that, please write back or email support@dronedeploy.com for additional support.

Best,
Hannah

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@JamesChung, I would fly your normal nadir flight and take control of the aircraft at the end. Or you can land and fly it with DJI if you don’t have enough battery. From there you can free fly around your object at a 45deg gimbal angle and take a photo about every 5-10deg around just about any object. This would be about 36-72 images depending on the size. You can use 3D mode, but it is going to take ALLOT of photos and at a 60deg angle which is not optimal for good 3D modeling.

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Thanks @MichaelL! Fly “manual” was what I was looking for. So per DroneDeploy’s recommendation, I should fly twice around the subject. Each manual pass at a different altitude using 45deg gimbal angle.

I will go back out to the USS Hornet and try it again. :slight_smile:

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Correct. I would try 60deg close enough in to just get the top and bottom of the structure and 45deg 25% further out. The middle of you image should be the middle of your subject at that point. I can’t wait to see it!

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Great! @JamesChung, that sounds like an excellent 3D mapping project—I’d also love to see it if you can share! Hope it goes well, and let us know if you have any issues. Thanks for the great advice as always, @MichaelL!

Best,
Hannah