so ive been doing mapping work for a mid-sized construction company for about 8 months now, mostly progress monitoring and earthwork volume calculations. been using DroneDeploy because thats what the company already had a license for when i started. its fine, gets the job done, the automated processing is pretty painless and the web interface is nice for sharing deliverables with clients who dont know anything about GIS.

but ive been hearing a lot from other surveyors that Pix4D gives significantly better accuracy especially for the point clouds, and one guy i met at a site told me the volume calculations are noticeably more reliable when you have a lot of terrain variation. our sites have a decent amount of grade change so this actually matters to us.

the thing is Pix4D is considerably more expensive and the company is already kind of skeptical about whether the drone program is pulling its weight financially. hard to justify a software switch when what we have technically works. but if the accuracy difference is real and documentable i might be able to make the case. anyone actually done a proper side by side on this or am i just hearing bias from Pix4D fanboys

done both pretty extensively and honestly the accuracy difference is real but how much it matters totally depends on your workflow and GCP setup. if youre flying with solid GCPs and your overlap is good ? like 75/75 or better ? both platforms will get you to survey-grade on flat to moderate terrain. where pix4d pulls ahead is complex scenes, dense vegetation edges, and yeah, significant grade changes like you mentioned. the point cloud density and the way it handles occlusions is genuinely better in my experience.

that said dronedeploy has closed the gap a lot in the last year or two. their processing engine isnt the same joke it used to be. for straightforward construction progress stuff i honestly wouldnt bother switching unless you're delivering to clients who are actually checking your numbers against ground truth. if theyre just looking at the orthomosaic and going 'yep site looks good' then you're probably fine where you are.

the other thing nobody talks about is how much time you spend in the software doing corrections and exports. pix4d desktop gives you way more control but it also means way more rabbit holes to fall down. dronedeploy being cloud-based and streamlined saves a ton of time if throughput matters to you.

we switched from DD to pix4d about a year ago for exactly the volume calculation reason and tbh the difference in stockpile volumes was sometimes 3-5% which is not nothing when you're billing on cut/fill. might not matter for progress photos but for earthworks that adds up fast. just something to think about when making the cost argument to your company.