Hi! It's my first work with Houdini Engine to Unreal. I created a terrain in Houdini, saved digital asset .hda and I imported it into UE4. Now, I would like to know if I can save the changes made on Landscape in Unreal (ex. sculpt, Landscape spline for road…) in the .hda file and review them in Houdini. If it's possible, someone can help me to understand how I can do it?

Thanks.

Hi,

What you want to do is possible, but you won't be able to “save” the modification made in Unreal in the hda file.

- Your first asset generates Heightfields in Houdini, and converts them as landscape in Unreal.

- You then modify this landscape in UE4 (sculpt etc..)
At this point, before doing any sculpting or modifications to the landscape I recommend that you bake the landscape generated by the first hda. This will break the link between the HDA and the landscape. If you dont do that, recooking the HDA (by changing parameters) will recreate the landscape, and all the edit done in Unreal will be lost…

- To bring the edited landscape back to houdini, all you need is a simple hda file with an input (either a sop input, or an object merge node with its object path parameter promoted to the asset).
In unreal, set that input to a landscape input, and select/commit the edited landscape.

- The updated landscape is now in unreal's internal Houdini scene, you can view it via File > Open Scene In Houdini or you can save it to .hip.

Thanks for your answer, but I don't find where I can save .hda modified in Unreal. I have attached Ue4 images.
- In the image1 I've baked .hda on landscape. Then I sculpted landscape.
- In the image2 I don't understand where I can save my updated file.
I also attach the .hda file with the base heightmap.
Another question is: how can I keep the changes I do in unreal (like sculpt or paint with Landscape tool) on top of the base houdini configuration, so that a change of the basic configuration would inherit the man made Unreal changes ? Now i noticed that the unreal changes are lost when editing the basic configuration. Maybe it exist a node where I can “store” the changes of height and paint made in Unreal (maybe like a overlay heightmap for the Unreal modified)?

dpernuit
Hi,

What you want to do is possible, but you won't be able to “save” the modification made in Unreal in the hda file.

- Your first asset generates Heightfields in Houdini, and converts them as landscape in Unreal.

- You then modify this landscape in UE4 (sculpt etc..)
At this point, before doing any sculpting or modifications to the landscape I recommend that you bake the landscape generated by the first hda. This will break the link between the HDA and the landscape. If you dont do that, recooking the HDA (by changing parameters) will recreate the landscape, and all the edit done in Unreal will be lost…

- To bring the edited landscape back to houdini, all you need is a simple hda file with an input (either a sop input, or an object merge node with its object path parameter promoted to the asset).
In unreal, set that input to a landscape input, and select/commit the edited landscape.

- The updated landscape is now in unreal's internal Houdini scene, you can view it via File > Open Scene In Houdini or you can save it to .hip.

Hi, when I'm doing this, UE4 crashed in FHoudiniApi::CreateHeightfieldInputNode. Can you please help me solve this? Thank you very much.

jie414341055

dpernuit
Hi,

What you want to do is possible, but you won't be able to “save” the modification made in Unreal in the hda file.

- Your first asset generates Heightfields in Houdini, and converts them as landscape in Unreal.

- You then modify this landscape in UE4 (sculpt etc..)
At this point, before doing any sculpting or modifications to the landscape I recommend that you bake the landscape generated by the first hda. This will break the link between the HDA and the landscape. If you dont do that, recooking the HDA (by changing parameters) will recreate the landscape, and all the edit done in Unreal will be lost…

- To bring the edited landscape back to houdini, all you need is a simple hda file with an input (either a sop input, or an object merge node with its object path parameter promoted to the asset).
In unreal, set that input to a landscape input, and select/commit the edited landscape.

- The updated landscape is now in unreal's internal Houdini scene, you can view it via File > Open Scene In Houdini or you can save it to .hip.

Hi, when I'm doing this, UE4 crashed in FHoudiniApi::CreateHeightfieldInputNode. Can you please help me solve this? Thank you very much.

I found it was because there is two interfaces missing in the libHAPIL.dll which is `CreateHeightfieldInputNode` and `CreateHeightfieldInputVolumeNode`, why is that happening?

@jie: I've replied on the other topic, looks like you have mismatched versions of Houdini and the UE4 plugin.
reinstalling a more recent version of H and the plugin that comes with it will solve your issue.

@Mary: Im not sure what you're trying to do, could you give us more details?

If what you want is:
- use an HDA to create a “base” landscape
- modify that landscape in Unreal via the paint/sculpt tool
- modify parameters on the source HDA that created the “base” landscape to generate a new one, but keeping the manual edits made in Unreal.

Then this will not be possible, as HE will not know of the edits made in unreal, and any change in the HDA will modify the landscape. Since Houdini doesn't know the edits that were in Unreal, they will be erased by the newly generated landscape.