Camera view is not updated

[Lee]

Hello every,

  I encountered an issue when setting up animation in Fluent 2025 R2, each time the animation updates, Fluent displays the following message:

“The camera view is not updated because the camera position cannot be directly on top of the camera target position. That is, the up vector must be perpendicular to the line of sight, they cannot be collinear. When the provided up vector is not perpendicular to the line of sight, the up vector is projected onto a plane that is perpendicular to the line of sight. This updated vector is used to determine the positive direction of the y-axis. The direction remains unchanged because either the newly provided up vector's projection is the same as the current camera's up vector direction or the provided up vector is in the line of sight.”

  These messages slowed down the animation refresh rate, especially when I used the DPM particle tracking feature, as the number of particles increased (for example, around 1500 particles), the update of animation became extremely laggy. However, if I changed the camera viewing angle (as shown in the attached image), even with 8000 particles, the animation ran smoothly without any lag.

  This issue did not occur in Fluent 2022 or earlier versions, where the same setup and particle count produced smooth animations.

  Could anyone please explain why this happens and tell me how to solve it?

  Thanks in advance!

Figure 1 desired view

Figure 2 warning message

 

Figure 3 a camera view along the X-axis