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"

Office Holiday

Epic Games' offices will be on holiday from June 22nd to July 7th. During this period support will be limited. Our offices will reopen on Monday, July 8th. 

How can I accomplish proper translucency for wax?

Ok. I have been trying to accomplish this for a few weeks now.

The set up is, I am trying to identify the best approach to lighting for transparency. From the image below I've tried lighting from a particle (affecting translucency) versus dropping a point light over the surface to be lit. Also, I'm not getting the subsurface effect I am after.

The candle model itself has varying thickness's which I would expect the light to transmit accordingly through the thickness. But, I read in the docs that opacity now is used as a thickness indicator. Do I need to paint a custom map to identify the proper thickness's??

Also, the scale of the "wax" is off. Too much scattering is happening. Is there a place to set the scale for hte translucency calculations?

Lastly, the thin walls of the wax ball look like they are getting clipped, like it is not depth tracing. Maybe this is a limitation I'm not aware of.

Cool. It's a lot to ask, I'm just flat out not understanding why this is looking so crummy.

Thanks everyone. alt text

Product Version: Not Selected
translucency.jpg (142.6 kB)
more ▼

asked Nov 14 '14 at 06:46 AM in Rendering

avatar image

1 2 3 4

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

2 answers: sort voted first

It needs to be Opaque and SSS, not Translucent.

more ▼

answered Nov 14 '14 at 02:54 PM

avatar image

16.8k 671 167 676

avatar image funwithayoyo Nov 15 '14 at 03:46 AM

Hey Jacky. Changing that does indeed start to give me the effect I am after. I do notice that I am getting pretty gross banding on the edges. I thought this might be due to the lightmap settings and set an override up to 512 to see if that helped and it does not.

The particle is now NOT emitting light (since there is no translucency to effect) and a point light has been dropped down to pick up that job.

Would you know where the banding is coming from and potentially how to resolve it?alt text

opaque_sss.jpg (54.8 kB)
avatar image funwithayoyo Nov 16 '14 at 06:16 PM

After reviewing the docs again I saw it mention, "Point light shadowing not yet supported".

So, this subsurface is intended to produce a light scattering effect, with all lights but the one light type that will best describe a wax candles primary function? Providing light from a flame which is best described by a point light?

In this particular scenario would you know an alternative to using a point light to emit light that would replicate the emitting nature of a point light?

avatar image Jacky Nov 16 '14 at 06:33 PM

Sorry for the late response. Yeah, it looks like the current SSS still has limitations like that. Maybe(hopefully) Subsurface profile will solve this problem when they integrate backscattering to it. Until then you can fake it with an emissive material i suppose. You need a gradient alpha mask so that the top of the candle is more lit and it gets gradually darker towards the bottom.

avatar image funwithayoyo Nov 16 '14 at 06:45 PM

Totally cool. But, how dare you have a life outside these forums. I was going to try just that, ramped emissive.

If I may ask though, ramps. I've seen how to create one though how to do yoo control directionality. Example, I want to ramp from black to white upwards, but what if I want it reversed? a 1-minus to invert?

Or what about a ramp from left to right? Take the original and rotate it?

Thanks for your time Jacky!

avatar image Jacky Nov 16 '14 at 06:58 PM

Yeah, OneMinus inverts and CustomRotator rotates. :) Also, if you are using LinearGradient node only OneMinus will work, since lineargradient will give you both horizontal and vertical gradients as U and V so you dont need to rotate.

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

I think an actual texture with some wax details helps enhance the look of the wax. alt text

a normal map will further enhance that effect ofcourse. So far what you have been doing looks fine, perhaps you hit the current limitations of SSS? https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/LightingModels/SubSurface/index.html

more ▼

answered Nov 14 '14 at 02:29 PM

avatar image

9.2k 286 64 330

avatar image funwithayoyo Nov 15 '14 at 03:47 AM

Hey man, thanks for the comment. I may actually take up your recommendations. Thanks.

(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