How expensive are decals?

Development World Creation
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1

hey guys,
I’m just wondering how expensive decals are? is there a deep inpact for the performance?
I’m pretty sure that i read somewhere that decals are very expensive…

2

I think this was one reason go make them use the deferred rendering pipeline. They should be less taxing on performance now.

3

Thanx!
Is deferred rendering a avaiable option or is every decal set automaticaly set to deferred rendering?

4

I think it is the standard, but there is a bit of a catch to it in the current version (4.0.2, haven’t tested it in 4.1 yet): You don’t get correct lighting of decals with indirect light, but there is a workaround. I have copied the relevant section out of my wiki:

Currently, als of UE 4.02, decals do not work with indirect lighting (deferred model). There is a workaround which works as follows:

Change BaseEngine.ini and enter the following entries under [SystemSettings]

r.EarlyZPassMovable=1
r.EarlyZPass=2
r.DBuffer=1

Then, use one of the DBuffer blend modes for the decal material.

I got it working correctly with indirect / baked lighting this way. Hope this helps.

Cheers,
Michael

5

Many Thanx!

6

You’re welcome !

7

Yes it’s much cheaper than before. A little tweak is needed by Epic for it to be rendered correctly as it got decoupled by lighting (Deferred Rendering).