How to reverse the control of camera zoom using the mouse wheel?

[GF-Huang]

Intro

Now, scrolling the mouse wheel up zooms out (moves away from an object). I want the opposite behavior—how can I achieve that?

My setup

Windows 11 25H2

mujoco                    3.6.0
mujoco-mjx                3.6.0

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.

[devshahofficial]

I think this issue may contain two different reports: the title asks about reversing mouse-wheel zoom, while the body describes an rgba="1 0 0 1" sphere rendering green. For the zoom direction, simulate currently applies wheel zoom in simulate/simulate.cc via mjv_moveCamera(..., mjMOUSE_ZOOM, ..., -zoom_increment * sy, ...), so reversing it would require changing that sign or adding a viewer option. For the color issue, it would be better as a separate bug with the exact renderer/backend used, since red rendering as green sounds unrelated to camera controls.

[GF-Huang]

I think this issue may contain two different reports: the title asks about reversing mouse-wheel zoom, while the body describes an rgba="1 0 0 1" sphere rendering green. For the zoom direction, simulate currently applies wheel zoom in simulate/simulate.cc via mjv_moveCamera(..., mjMOUSE_ZOOM, ..., -zoom_increment * sy, ...), so reversing it would require changing that sign or adding a viewer option. For the color issue, it would be better as a separate bug with the exact renderer/backend used, since red rendering as green sounds unrelated to camera controls.

That is the default issue template, not my mind.