Poke Through, or poke-through is the bane of all 3D artists when it comes to using tight fitting clothing. Whether that be stockings, tights (pantyhose), a catsuit or something else, a tiny spot of poke through can pull a sigh out of the best of us.
Never fear though there are some ways to prevent it, and I have a little theory on an annoying possible issue when using smoothing.
The simplest way to be rid of poke through is to use any morphs available on the clothing. If the piece of clothing gives you a morph for the specific area the poke through is appearing, even better.
If you have a fit helper morph set like SY Clothing Fit Helper for Genesis 8 Female (there is a male one too), then you can use them even when the clothing doesn’t provide a morph.
Failing that you can generally find a morph called ‘FBMExpandAll’ on clothing. This works like a Push Modifier and pushes the entire clothing item outward.
A Push Modifier is a relatively simple way to eliminate poke through.
All you need to do is select the clothing item then go to ‘Edit’ -> ‘Object’ -> ‘Geometry’ -> ‘Add Push Modifier’. This will apply the push modifier to your clothing item and dial it to 1. You can then dial it down to the required amount.
You can also use a Push Modifier Weight Node to paint weight maps if needed, but maybe more on that in a later tutorial.
Smoothing & Collision
This is where I’m not sure about how much is known on this issue. This generally happens when using high sub-division levels, like those needed for HD morphs.
Kala 8 HD with poke through in stockings
Here you can see some poke through issues on Kala 8 HD. This was rendered with Render sub-division set to 4 so the HD morphs are visible. Of interest though is there were no signs of poke through in the viewport before rendering.
It should be noted that the stockings were set to sub-division 2 for render and 1 for viewport. Kala was set to 4 for render and 2 for viewport.
Kala 8 HD with no signs of poke through
As you can see above, there were no signs of poke through when a iRay preview was done in the viewport.
After a little investigation I think I may have found why this might happen. I believe it is all to do with smoothing calculation and sub-division level.
Kala 8 HD poke through fixed
The above render was done after increasing the viewport sub-division to the same as the render sub-division. In this case sub-division level 4.
To increase viewport sub-division past 3 you may need to unlock the morph. Click on the cog to its right, press ‘Parameter Settings’ and uncheck ‘Use Limits’.
My thoughts are that Daz does not re-do the smoothing and collision calculations using the render sub-division level before doing the render and so if the disparity in geometry is too great you will see poke through. Especially on form fitting clothing.
Setting the viewport sub-division as close as you can to the render sub-division level will mean Daz calculates smoothing and collision on geometry nearer to the final render geometry and so reduces or eliminates poke through.
I have now done numerous tests on a render series I am making and this seems to have held true for every single one of them.
Poke Through Begone!
I’ve seen a few posts on the Daz forums about this issue and the general response seems to be that it is either the fault of displacement maps, or smoothing not being turned on. When those have been disproven the answer is generally ‘just use a push modifier’.
I wasn’t satisfied with this answer though, why would the viewport show no poke through but the final render be riddled with it. That’s why I decided to make this article.
I’m not sure if this is a bug, and Daz should recalculate smoothing and collision using the final render geometry, or if it is the expected functionality. In fact I’m not even sure that is what is happening, but given the evidence I think it is a very good possibility.
I hope this has helped in some way and if you have any thoughts, comments or if I’ve missed something obvious and there is a setting to fix this, please do let me know. While I’ve been using Blender for a while I’ve only really been using Daz seriously for the last year or so.