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"

Texture Composition

I only found an option to "add normal roughness to alpha channel" from another normal texture. But that's not really what I need.

I am putting together some landscape textures and (since samplers are limited in number) I want to use the alpha channels of diffuse and normal map for roughness and specularity. Since these are both grayscale, it seems like the best solution. But can I "compose" textures like this inUE4 or do I have to do it externally?

Product Version: UE 4.12
more ▼

asked Jul 31 '16 at 09:48 PM in Rendering

avatar image

643 67 82 117

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

1 answer: sort voted first

Most likely you will have to do it externally.

Be advised, however, that storing alpha channel virtually doubles memory usage of your texture, and using additional channels in normal maps provides a bunch of complications. There are some discussions on the forum about that:

***Link1*** ***Link2***

more ▼

answered Aug 01 '16 at 01:34 AM

avatar image

7.9k 130 31 293

avatar image MaxPower42 Aug 01 '16 at 03:08 PM

Hmm, I wasn't planning on investing too much time on this :/

Is there something you would recommend instead?

Like, not using alpha-channels at all but rather a third RGB-texture that stores up to 3 extra grayscale maps?

I WOULD require fewer samplers by using alpha channels, though, right? So it's "sampler-eficiency" and possible glitches vs memory-effeciency?...

avatar image Deathrey Aug 02 '16 at 08:53 AM

Storing 3 masks in RGB texture is a good option, if you don't mind that one mask might slightly bleed into the other one. If samplers are your ultimate limiting thing, then you do not have much choice, but to use those extra channels.

(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