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"

Planar Reflections in 4.15 not rendering any faster with lower screen percentage

In previous versions of the engine, I would get a huge fps increase by lowering the screen percentage on the planar reflections actor. In 4.15, setting this to 100 percent renders faster than previous versions at 100 percent, but lowering it seems to have no effect on frame time. This has caused scenes with water to take a significant fps hit.

Product Version: UE 4.15
more ▼

asked Mar 07 '17 at 03:14 PM in Bug Reports

avatar image

132 10 18 230

avatar image Ed Burgess ♦♦ STAFF Mar 09 '17 at 09:39 PM

Hey 3dMoss,

I didn't reproduce this behavior on my end so it could be because I have a different testing setup that yourself. Here are the steps I took:

  • Created a blank project (with support global clip plane enabled for planar reflections).

  • Put in several planar reflection actors to ensure a performance hit.

  • Scaled up the floor mesh and applied a reflective metalic material(see screen for how I had it set up)

alt text

  • Enabled Stat FPS in the console

  • Took note of FPS at screen percentage 0, 100, and 50

  • I then did the same test in 4.15

In 4.15 I noticed the FPS increase as the screen percentage lowered.

To ensure we are testing under the same conditioned I would recommend testing in a blank project.

testscreen.jpg (335.1 kB)
(comments are locked)
10|2000 characters needed characters left
Viewable by all users

1 answer: sort voted first

Thanks for checking this Ed. I can confirm the same result as you in a blank project. I tried that previously, but didn't think to duplicate the reflection actor to exaggerate the hit. It seems that planar reflections are now more efficient to render, and the render time difference between 20% and 100% is much less than in 4.12 which my project was upgraded from. After unchecking some unnecessary flags, the frame time is now fine, with much better quality reflections. I don't think 4.12 had flags, and I'm guessing that is why the difference in frame time when lowering the resolution was so much greater. Thanks again.

more ▼

answered Mar 10 '17 at 02:44 AM

avatar image

132 10 18 230

(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