How to get LineTrace equivalent feature with clouds

Development Asset Creation
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1

Hi,

Working on simulation, we need to determine if targets are visible. We usually manage to get the information using LineTrace requests / APIs. However, (volumetric clouds) are not considered for those requests.

Are we missing some parameters within the LineTrace mechanisms to have them considered ? Is there any equivalent ?

If there is no pre existing capability, how would you be approaching this problem ?

Thanks,

Basile

2

Hi Basile,

Your observation is correct where volumetric clouds do not have collisions to be considered for LineTrace as they’re a cloud rendering system. That being said there are some things we can make use of to approach this problem as there is no equivalent built in.

An approach would be to sample the volumetric cloud material yourself. Here’s a discussion with a public example on how they did it. It describes the steps where you’d duplicate your cloud material that has a UVW coordinates parameter, create a 1px render target and make a dynamic material instance of your cloud material duplicate so you can change the UVW coordinates at runtime wherever you need to sample.

Another thing you could do, if you’re okay with approximates and clouds are mostly static, is to place an invisible collision component matching the volumetric cloud as a proxy but as mentioned it’s a vague approximate and may not visually line up well.

For additional information, here’s the documentation on the volumetric cloud component and a great video that deep dives into the volumetric cloud system. In addition to this, the volumetric cloud shader information can be found in VolumetricCloud.usf.

Please let me know if this information helps!

Regards

3

Hi John,

Thanks for the answer and follow-up.

Unfortunately we are fully busy on some performance issues at the moment (like [Content removed] ) and cannot afford to look into new feature implementation. I guess we will have to come back at this at a later point.

Best,

Basile

4

Hi,

I wanted to check-in to see if the above information helped out?

Please let me know, thank you!

Regards

5

Sounds good to me, I’ll be closing this case for now, but please feel free to respond here to reopen it when you’re available to.

Thank you!