# Applying pressure to the projection of a surface
**URL:** https://prepomax.discourse.group/t/applying-pressure-to-the-projection-of-a-surface/3036
**Category:** General Questions
**Created:** [October 23, 2025, 9:05am UTC](https://prepomax.discourse.group/t/applying-pressure-to-the-projection-of-a-surface/3036 "2025-10-23T09:05:12Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@gnikol](https://prepomax.discourse.group/u/gnikol)
#### Post date: [October 23, 2025, 9:05am UTC](https://prepomax.discourse.group/t/applying-pressure-to-the-projection-of-a-surface/3036/1 "2025-10-23T09:05:12Z")
Ηι,
How can I apply a pressure load (e.g., snow load) on a curved or inclined surface, whitch is aligned with a global axis (e.g., -Z) instead of perpendicular to the surface? Using Pressure applies the load normal to the surface, which doesn’t work for this case. With Surface Traction, I need to input the total force, calculated as the load per square meter (e.g., 1 kN/m²) multiplied by the surface’s projected area onto the XY plane. Is there a built-in way in PrePoMax to apply such a load directly or calculate the projected area, or must I compute the projection in external CAD software?
Best regards,
George Nikolaidis
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### Author:  [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)
#### Post date: [October 23, 2025, 9:23am UTC](https://prepomax.discourse.group/t/applying-pressure-to-the-projection-of-a-surface/3036/2 "2025-10-23T09:23:50Z")
Since PrePoMax 2.4.0, you can use part areas (and volumes) as parameters in equations. So you could define a surface traction as force divided by area (projection would have to be calculated, though).