Depth map Unity

Software
1

Hi everybody,

I am trying to figure out the depth map in Unity.
It seems the depth values I am getting are not linear?

I am reading the depthmap values like this (code screenshot).

Basically I am taking the Depth map from the zed rendering plane which is this:
depth = zedCamera.CreateTextureMeasureType(sl.MEASURE.DEPTH, resolution);

Then I am looking at a specific point in space to check the actual depth value.

As you can see those values are not linear. It seems to be some sort of exponential curve, which does not make sense. I doublechecked with the greyscale values in the depth map and I see a similar exponential augmentation towards zero when you move further away from the camera.

Is there anybody who could point me in the right direction to get actual good solid linear depth information out of the Unity sdk?

Thank you so much in advance :pray:

code
code948×610 66.2 KB

15feet
15feet1920×1032 166 KB

10feet
10feet1920×1032 167 KB

5feet
5feet1917×1032 163 KB

2

Hi @wimvanhenden-tool !

I think you get the correct values.
The distance measurement of the ZED SDK is the meter. From your first screenshot, you get a “1162.763” distance value for 15 feet (last value in the console).

15 ft~= 4.5m
1162/255 ~= 4.5

So you should be able to retrieve the value by not multiplying by 255, or dividing by this much afterwards.

Unfortunately, it’s not possible to change the measurement unit natively from our Unity plugin, so you need to convert the output for the unit system you need from meters.

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3

Hi @JPlou you are absolutely right. I forgot about the *255 that I had in there. I had that in there from checking a previous color texture. That threw me off but it all seems to be correct indeed.

Thank you!

1 Like