RF10 - issue with object interaction using imported obj or alembic

[Scott Broad]

I am having an issue with the way imported meshes are interacting, specifically with realwave. I am getting a very wide falloff and odd looking interaction with anything that is imported, vs using a primitive created directly. See attached images. I can't see any differences in the node tab settings... Same result whether importing obj or abc, with or without baked in animation. Meshes are being exported form maya 2017.

[Thomas Schlick]

Any chance to get these models? There are some things I'd like to try out. If you don't want to share them here just send me a PM.

[Scott Broad]

I have attached a RAR with the imported obj used in this scene. The other object is a native RF cylinder, scaled up. Let me know if you find anything.

Thanks.

[Thomas Schlick]

Unfortunately I get an error when I try to open the rar. Don't know what went wrong, but could you please post a zip instead? Thanks.

[Scott Broad]

Ok, zip attached.

[Thomas Schlick]

It seems as if there are two reasons for this behaviour: scale and the ship's shape. I set geometry scale to 0.1 and then the offset was almost gone. In order to see if it has something to do with your model I've created a rough copy of your object, but my version behaved in exactly the same (wrong) way as yours. But the object's shape is also responsible for the waves' weird behaviour.

Therefore I run another test with a boat modelled from a cylinder in C4D and exported it as SD, OBJ, and ABC. With this object I got a correct bow wave, even with a geometry scale of 10.

It might sound strange, but I recommend creating a new object from a basic cylinder (I had just 10 segments). RealWave is a very old technology and it's sometimes necessary to find a compromise. I've attached my C4D model as a reference:

https://drive.google.com/file/d/1Yln3Yo ... sp=sharing

[Scott Broad]

It's really unfortunate that my external geo is having this issue... especially coming from Maya. I have seen more complicated shapes used in RF tutorials without this problem. Old tech or not, I would hope that Nextlimit could figure this out, I'll see about opening an official ticket.

Thank-you for your help in this.
-Scott

[Thomas Schlick]

I'll see about opening an official ticket.

Sure, just get in touch with tech support.

[Scott Broad]

So I noticed your shape was about 1 tenth the scale of mine. I am working in Maya at 1 centimeter = 1 meter, standard for Maya in simulation. The real world boat I am basing these animations off is roughly 90 meters long, so my shape is 90 cm in Maya. As a test I scaled it down to 9cm, froze out all transforms, exported from Maya and imported that into Realflow. No issues now, even when scaling up by 10, back to proper proportions...

Does Realflow have some interpretation or conversion settings for object/scene scale?

[Thomas Schlick]

Scale was one my suspects from the very beginning. With my C4D boat I was able to get good results - even when I changed scale to 10:1. So, I think it has to do with RealWave itself and you won't have any problems with the same object in Dyverso or Hybrido simulations.
I've seen artifacts or strange behaviours with large surfaces and/or interacting objects in the past. In many cases it was possible to fix these issues, or reduce them at least, but some simply persisted.

I've filed a bug report, but I don't expect a solution for this issue in the short- or mid-term. Therefore I really hope that the scale workaround fixes the problems in your current project.