Houdini Camera Export to Unreal Engine

   173   4   1
User Avatar
Member
32 posts
Joined: Oct. 2013
Offline
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
Edited by madguru - Nov. 4, 2017 01:28:18
User Avatar
Member
149 posts
Joined:
Offline
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)
Edited by galagast - Nov. 9, 2017 17:02:12

Attachments:
hou_to_ue4_cam.png (200.8 KB)
cam_to_ue4_v1.zip (32.2 KB)
hou_to_ue4_cam.gif (241.1 KB)

User Avatar
Member
32 posts
Joined: Oct. 2013
Offline
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
User Avatar
Member
149 posts
Joined:
Offline
Glad I could help! Cheers!
User Avatar
Member
132 posts
Joined: July 2005
Offline
Thanks for detailed explanation!
BTW is there any solution for “import camera from UE to houdini”?
  • Quick Links