RotateAboutAxis broken

Development Rendering
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1

RotateAboutAxis seems to be horribly broken, resulting in… well nothing explainable really. Whatever is happening, it shouldn’t be happening at all. See the examples below for how broken it is, it doesn’t even respond to input.

Examples:

X-Axis
Input Vector: 1,0,0
Rotation Angle: 0
Rotation Axis: 1,0,0
Expected Output: 1,0,0
Actual Output, 0,0,0

Input Vector: 0,1,0
Rotation Angle: 0
Rotation Axis: 1,0,0
Expected Output: 0,1,0
Actual Output, 0,0,0

Input Vector: 0,0,1
Rotation Angle: 0
Rotation Axis: 1,0,0
Expected Output: 0,0,1
Actual Output, 0,0,0

Y-Axis
Input Vector: 1,0,0
Rotation Angle: 0
Rotation Axis: 0,1,0
Expected Output: 1,0,0
Actual Output, 0,0,0

Input Vector: 0,1,0
Rotation Angle: 0
Rotation Axis: 0,1,0
Expected Output: 0,1,0
Actual Output, 0,0,0

Input Vector: 0,0,1
Rotation Angle: 0
Rotation Axis: 0,1,0
Expected Output: 0,0,1
Actual Output, 0,0,0

Z-Axis
Input Vector: 1,0,0
Rotation Angle: 0
Rotation Axis: 0,0,1
Expected Output: 1,0,0
Actual Output, 0,0,0

Input Vector: 0,1,0
Rotation Angle: 0
Rotation Axis: 0,0,1
Expected Output: 0,1,0
Actual Output, 0,0,0

Input Vector: 0,0,1
Rotation Angle: 0
Rotation Axis: 0,0,1
Expected Output: 0,0,1
Actual Output, 0,0,0

2

Hello,

Could you provide a screenshot of the setup that you are using to reproduce this issue?
Have you been able to reproduce this in a clean project?

3

Hello,

I was looking into this issue, and came across a forum post that states that Rotate About Axis returns an offset. While this might not be exactly the same problem that you’re running into, this thread does contain some good information: Combining Rotations (RotateAboutAxis) for World Position ffset - Rendering - Unreal Engine Forums

Let me know if you have any other questions.

Have a great day

4

Hey Sean,

the project I tried this on is a clean project (Blueprint, Blank, Starter Content, Max Quality). For the screenshot of the Material setup:

86861-ue4editor_2016-04-14_17-17-53.png
86861-ue4editor_2016-04-14_17-17-53.png1928×1058 453 KB

5

Wait, does this node calculate an offset to the original position?
That’s not how this node should work, if I wanted an offset, I’d calculate it myself from the result of that.

6

Yeah that is exactly the problem I ran into. The documentation for the node does not state that at all (please fix the documentation at some point).
Also this means that I basically have to undo the work the node did. There goes performance…