Unreal Engine 5 - messed colours

[Seweryn]

Hello,

I imported the point cloud into Unreal Engine, but the colours are messed as if the columns were read wrongly. According to this topic on the Unreal Engine forum: https://forums.unrealengine.com/t/lidar ... ors/903981
I am not the only one with this problem.

Does anybody know how to solve this issue? I noticed that the unreal point cloud plugin forum looks quite abandoned: https://forums.unrealengine.com/t/lidar ... oud/157264

[nyda]

Hello,

I imported the point cloud into Unreal Engine, but the colours are messed as if the columns were read wrongly. According to this topic on the Unreal Engine forum: https://forums.unrealengine.com/t/lidar ... ors/903981
I am not the only one with this problem.

Does anybody know how to solve this issue? I noticed that the unreal point cloud plugin forum looks quite abandoned: https://forums.unrealengine.com/t/lidar ... oud/157264

I didn't try yet, but I would say that blue and red are inverted.
Did you reach out Unreal support?

Gio

[smacl]

I didn't try yet, but I would say that blue and red are inverted.

Looks very likely to be the issue. In scanning and photogrammetry we typically see colour as RGB, in many computing SDKs it is BGR, e.g. in OpenCV

[Seweryn]

Thank you @nyda and @smacl for your answers.

As fas as I know, there is no Unreal support except for the forums which are abandoned / nobody cares since my post there is 3 weeks old.

Looks very likely to be the issue. In scanning and photogrammetry we typically see colour as RGB, in many computing SDKs it is BGR, e.g. in OpenCV

I suspected something similar: that Unreal doesn't know about the intensity, and therefore skips one column. Is it possible to check that in Cloud Compare?

[badam]

Well you could try to flip rgb to bgr in cloud compare. Just export colors as scalar field flip them and then create colors based on the flipped scalar fields.

[Seweryn]

Thank you @badam for your suggestion.

I was trying to do what you said but had some trouble doing it properly in Cloud Compare. While going around the obstacles, I discovered that Unreal Engine probably has a problem with SOME e57 files.

The e57 file imported directly into UE --> wrong colours
The same file brought to CC and exported as txt file -->correct colours.

All that happened automatically, without me changing any columns.

At that point it would be easy to say that UE has troubles with all e57 files, but I imported a different point cloud and that one was read without issues.

[gnuiorc_mda]

Thank you @badam for your suggestion.

I was trying to do what you said but had some trouble doing it properly in Cloud Compare. While going around the obstacles, I discovered that Unreal Engine probably has a problem with SOME e57 files.

The e57 file imported directly into UE --> wrong colours
The same file brought to CC and exported as txt file -->correct colours.

All that happened automatically, without me changing any columns.

At that point it would be easy to say that UE has troubles with all e57 files, but I imported a different point cloud and that one was read without issues.

Thank you Seweryn!
I tried yesterday and I had the same problem as you.
I will try tomorrow with your solution

Gio

[nyda]

...
I will try tomorrow with your solution

It works!
The only issue is that the txt file is 3 times larger than the .e57

Gio

[badam]

if i recall correctly i used once unreal engine with laz point clouds and it was usable. And that is the most storage efficient file format but keep in mind that it can be a lossy compression it depends on your precision set during conversion/saving.