Landscape components go invisible with tessellation

Development Rendering
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1

Hello,

Downloaded 4.13.0 and did a simple distance based tessellation like I’ve been doing in 4.12 and older versions, except in 4.13 the landscape components are disappeared and only the ones appear when I fly over them. (This is not a tiled landscape).

Also “Used with landscape” checkbox is disappeared from the material editor.

2

“Used with Landscape” is no longer necessary.

We made some changes to tessellation for Landscape in 4.13. It should be unnoticeable, but we’ve had a couple of reports of invisible landscape components. Can you try removing your material from the landscape and re-applying it to see if it helps?

Did you apply a non-tessellated material to the landscape and the edit it, or did you make the material tessellated and then apply it to the landscape?

3

Hi Gareth,

Reapplying the material didn’t help.
Here’s what I did:

  1. Created a new material and applied to landscape - works fine
  2. Enabled tessellation (still nothing connected to any pins) - works fine
  3. Connected a 0 to tessellation multiplier pin - works fine
  4. Disconnected the 0 and plugged in the distance based tessellation setup like image above - components disappear
  5. Disconnected the distance based tessellation setup (nothing connected to any pins) - components disappear
  6. Disabled flat tessellation (no tessellation) and hit apply - works fine

Please let me know if you need any other kind of tests to be done.
Thanks

4

Thankyou very much. We are tracking this bug as UE-35494. We’re investigating this now and going to try to have it fixed for a 4.13 point release.

5

Thank you Gareth.

6

The fix has been committed and should be included in 4.13.1 (which should be released in a week or so).

7

Exactly what I came here to report. Glad to see it’s going to be a quick fix.

8

My UE4.13 is doing the same thing. But my UE4.12 doesn’t do this. And my material turns black.

I think something went wrong.

9

It will be fixed in 4.13.1 (due soon).

10

Hi Gareth,
We just got 4.13.1 and the problem is still there. Repro steps are exactly the same. I see it marked as resolved but really nothing has changed.

11

The invisible landscape or the black landscape?

12

Invisible landscape components. They appear as we approach them.

13

Can you upload your project for me to look at?

14

Sure. Will be posting the link here shortly.

15

Thanks!

16

Here’s a project demonstrating the issue:
https://drive.google.com/open?id=0B8r-amh_izuoVEFFcDZXcnVuLWs

17

Brilliant, thanks!

18

You’re welcome.
Please keep us informed if possible.
Thank you.

19

Just checked your project. Yep, chunks are disappearing exactly where first LOD transitions to the second.

Missing chunks are visible, when viewed in wireframe.

Stats landscape reports expected number of components rendered

1081×439 320 KB

1138×453 209 KB

Components are missing both in editor, in PIE, and in standalone.

20

I have debugged into the issue, and it seems like it’s trying to use the tessellation vertex shader on the LOD 1+ components when it’s not supposed to. Because there’s no tessellation shader bound after the vertex shader all the vertices get junked and nothing gets rendered.

Debug viewmodes are fine because they aren’t tessellation aware so it correctly disables tessellation for the vertex shader as well.

I should have a fix soon!