x

Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

Strange Rendering Artifacts in Preview 3

I'm seeing very strange artifacts in my project since upgrading it to 4.16 Preview 3. These assets are from the SupeerGrid Starter Pack, but they're really just simple world-aligned materials.

Almost looks like Z-Fighting, but there are no extra triangles there.

Video: https://youtu.be/XsZb2jMuUes

Product Version: UE 4.16 Preview
Tags:
more ▼

asked May 13 '17 at 10:59 PM in Bug Reports

avatar image

TheJamsh
820 60 97 140

avatar image TheJamsh May 14 '17 at 10:51 AM

Had to make the video private, sorry. If Epic need to see it, I can send them a direct PM on the forums.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

1 answer: sort voted first

Hey!

Thanks for reporting, it seems like a biggie :/

From what I understood there been changes in material Power node. Negative number powered to any number return negative number no matter what. And normalizing this negative number convert it to 1(White color on negative sides of meshes)

For now, just open Content/SuperGrid/StarterPack/Materials/Functions/UV/UV_ObjectScalable and add Abs node after TransformVector.

It should do the work, but honestly I'm not sure that new behavior of Power node is correct.

more ▼

answered May 15 '17 at 10:36 AM

avatar image

zeOrb
267 24 19 25

avatar image Chris.Bunner STAFF May 15 '17 at 03:32 PM

Hi zeOrb,

This isn't quite correct. In 4.15 and lower the Power node used to internally call max(abs(X), 0.000001) guessing at user intent by always wrapping negative inputs to positive outputs which was a fairly consistent source of questions and confusion. In 4.16 it now runs max(X, 0) which still tries to apply some safety to avoid common HLSL errors (where any value of X less than zero results in a NaN) but doesn't force behavior or cost on the user. This is now more correct from a shader point of view. Calculating the true result sign would add a few operations to every call because it's not how the language works by default and as it's not needed very often, we chose to avoid that.

If you're seeing different behavior please report it as a bug and we can try to get it resolved. This should all be listed in the patch notes and upgrade notes once they're published with the main 4.16 release.

Thanks, Chris

avatar image zeOrb May 15 '17 at 04:20 PM

Hey, Chris!

Thank you for such detailed answer, it clarifies a lot.

I just want to say that from user standpoint it was very confusing because previously I got the output which met my expectations, but now output was basically inverted and I was not able to understand the logic behind by my own.

I think it would be really useful to have a comment in node description which specify the expected output because it's differ from regular power function.

Thank you!

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question