Is the back of the wall composed of PEC in an urban scenario with 3D ray tracing?

XW

May I ask if the back of the wall is composed of PEC in an urban scenario with 3D ray tracing? As shown in the figure? Since if in the settings, the 3D IRT simulation in an urban scenario does not consider indoor coverage, then the rays will just reflect on the surface of the building walls. And all the buildings are wrapped in a material with some thickness. So if without considering indoor coverage, the back of the building wall (behind the material) is PEC and rays will go through the material and reflect perfectly from PEC? I would be grateful if you could answer my question.

Zeina

Hi XW,

For urban scenarios where indoor prediction is not requested for and IRT model, the thickness does not have any impact on the prediction. The reflection loss is computed on the interface air/wall. Hence the "back" of the wall you have mentioned and drawn is not considered and does not generate a reflected ray within the thickness of the wall.

I hope this clarifies it for you.

Best Regards,

Zeina

XW

Zeina said:

Hi XW,

For urban scenarios where indoor prediction is not requested for and IRT model, the thickness does not have any impact on the prediction. The reflection loss is computed on the interface air/wall. Hence the "back" of the wall you have mentioned and drawn is not considered and does not generate a reflected ray within the thickness of the wall.

I hope this clarifies it for you.

Best Regards,

Zeina

Hi Zeina,

Thank you very much for your reply. I'm clear now.

And may I ask for urban scenarios, if the ray tracing prediction on the wall surface could only be used for standard building? I designed a bridge by setting it as the horizontal plate with some thickness in the material setting (as shown in the figure), and I noticed it seems the surface prediction in Wallman is always gray and cannot be selected, and in Proman there is also no rays reflected on its surface.

Best wishes,

XW

Zeina

XW said:

Hi Zeina,

Thank you very much for your reply. I'm clear now.

And may I ask for urban scenarios, if the ray tracing prediction on the wall surface could only be used for standard building? I designed a bridge by setting it as the horizontal plate with some thickness in the material setting (as shown in the figure), and I noticed it seems the surface prediction in Wallman is always gray and cannot be selected, and in Proman there is also no rays reflected on its surface.

Best wishes,

XW

Hi XW,

Glad that helped.

Regarding the way the ray interactions are accounted for for this type of geometry, you can find some information in Table 2 below. Actually, reflect is accounted for for horizontal plates, it is only the penetration of rays within this type of building that is not computed. In your case, the reflection might be absent because of other settings in the prediction model.

 

Going back to the surface prediction, it is only available for standard buildings. This type of prediction is for walls. In case you need to obtain results close to your horizontal plate, you can do so by defining a rectangular prediction area at a height very close to that plate (should not be exactly on it).

Best Regards,

Zeina

 

XW

Zeina said:

Hi XW,

Glad that helped.

Regarding the way the ray interactions are accounted for for this type of geometry, you can find some information in Table 2 below. Actually, reflect is accounted for for horizontal plates, it is only the penetration of rays within this type of building that is not computed. In your case, the reflection might be absent because of other settings in the prediction model.

 

Going back to the surface prediction, it is only available for standard buildings. This type of prediction is for walls. In case you need to obtain results close to your horizontal plate, you can do so by defining a rectangular prediction area at a height very close to that plate (should not be exactly on it).

Best Regards,

Zeina

 

Hi Zeina,

Thank you for your reply. I think I might misunderstand the surface prediction in Wallman, I thought it is used for predicting rays reflecting on the wall before, now I got that it shows the power distribution on walls.

So for a horizontal plate, it is possible that rays could reflect on it. And the way to take into account rays reflecting on the wall is by selecting surface of buildings in Edit project parameter in Proman?  In my simulation results, there are some ray interactions on the bridge, but there are no rays reflecting on its surface. I'm not sure whether it's because the surface is created by the thickness of the material instead of a kind of wall (I set the thickness in the material is 3m so that the height of the bridge is from 5m to 8m). Or may I ask if there are any better ways to simulate a glass bridge with some thickness, as shown in the figure? Thank you in advance!

Best wishes,

XW

Zeina

Hi XW,

The surface prediction feature does not affect the ray interactions computations within ProMan. It is a feature that the user can activate if they need the prediction to be computed on these surfaces (walls).

Regarding the thickness, as I have mentioned before, it does not affect either the ray interactions computed.

I see that the thickness you are trying to model is big. In this case it is better to create your bridge as an indoor database, then import it to your .odb database ( Object -> Import Indoor Database). You can then set your propagation project in ProMan using this hybrid database. In this case you should activate the CNP indoor prediction from the Computation tab.

For more information on how to set a Hybrid Outdoor/Indoor model please refer to the corresponding user guide sections.

Best Regards,

Zeina

XW

Zeina said:

Hi XW,

The surface prediction feature does not affect the ray interactions computations within ProMan. It is a feature that the user can activate if they need the prediction to be computed on these surfaces (walls).

Regarding the thickness, as I have mentioned before, it does not affect either the ray interactions computed.

I see that the thickness you are trying to model is big. In this case it is better to create your bridge as an indoor database, then import it to your .odb database ( Object -> Import Indoor Database). You can then set your propagation project in ProMan using this hybrid database. In this case you should activate the CNP indoor prediction from the Computation tab.

For more information on how to set a Hybrid Outdoor/Indoor model please refer to the corresponding user guide sections.

Best Regards,

Zeina

Hi Zeina,

Thank you for your reply and suggestion about how to simulate my bridge. And apologize for my late reply.

I tried to use Hybrid Outdoor/Indoor model to simulate the bridge as shown in the figure real bridge.png. Firstly, I simulated the bridge in WallMan in an indoor scenario, as shown in the figure simulated bridge.png,  but when I import it into my urban scenario in WallMan, there is an error occurring as shown in the figure error.png. And if I selected Yes, the bridge will touch the ground instead of hanging in the air, which is not a bridge anymore (touching-ground.png). May I ask if there is any way to create a bridge (or a hanging thing) in an urban scenario? I would really appreciate it if you could help me, since I have been stuck here for a long time.

Best wishes,

XW