Hi,

I am using Houdini Indie. I've been able to export fbx models out of Houdini Indie. When I import them into Unreal, I use a uniform import scale of 100 to get the models in at an expected scale. I import the camera animation from the camera fbx exported from Houdini into sequencer, but I can't get it to match what I had in Houdini, with the scale on other objects. I tried scaling the camera after the fact in Unreal, but that did not work. Any advice on how I can get my camera animation into sequencer to accurately match what I had in Houdini in relation to the objects I have imported with a scale of 100?

Thanks,

Adnan

Hi, I've been trying to look into this for the past couple of days whenever I had time.

• I tried to check if the axes got swapped.
  
• Tried all sorts of matrix adjustments in Houdini before exporting to no avail.
  
• Watched a couple of ue4 camera import tutorials.
  
• Searched google for unreal camera import problems.
  

Then one common issue I noticed (dated for the past year or two) were cameras and objects getting imported at a 90 degree rotation in UE4.

A solution here [answers.unrealengine.com] recommended to rotate it -90 upon importing. But in the sequencer, we don't have that option.
So I went back to houdini and did the rotation prior to exporting.
Keep in mind that this should be a scene level rotation. (Like parenting the camera to a null placed at the origin, then rotating this null).

It almost worked, but..it was not rotated correctly when imported in UE4. :-(
Luckily, I also chanced upon another issue (while googling this) where there appears to be a rotation bug known in the sequencer here [answers.unrealengine.com]. Basically, if you turn a camera clockwise, it would turn counter-clockwise. >__<

So, simplest solution was I rotated the camera to +90 degrees.. not -90 degrees.
Next part of the puzzle was to also do the uniform scaling in Houdini, which simple enough to do.

Now when I imported it to UE4, it finally looked as expected (rotation wise).
Last pieces of the puzzle was to just match the camera properties.

Here are the parameters I converted from Houdini Camera to UE4 Camera:


The process seems to have transferred nicely:


I have also attached a sample hip file where I used CHOPs to do the rotation and scaling before exporting.

H16.0.745 Indie - cam_to_ue4_v1.zip (attached below)

Thanks so much for the detailed reply. I could not find any information about this anywhere else that I looked, but your solution worked.

Much appreciated.

Adnan

Glad I could help! Cheers!

Thanks for detailed explanation!
BTW is there any solution for “import camera from UE to houdini”?

Hi there.

Thanks so much for sharing that breakdown and the files.

Alas, I cannot get the data to line up in unreal even using your actual hip file and just rendering the FBX files with all your settings as they were when I downloaded the file.

What I'm doing in Unreal is the following:

1) file - Import into level… , select the objects.fbx file and accept defaults.
2) create new camera and right click it in the sequencer and say import - cam.fbx

I end up with a sideways camera and no object visible in the camera view.
If I hit “F” i see the geo does exist but it's tiny and fits inside the actor icon and is totally in the wrong spot.

Can anybody please break down the process in Unreal to bring both the camera and the geometry into unreal alligned like it was in Houdini for a dummy like me ?

Any help would much much appreciated !

Ah, I think I've worked it out now.

That rotation bug. I guess they fixed it cause when I export the camera with -90 rotation now it works