Author Topic: White Polypropylene - the hardest material of all?  (Read 18791 times)

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Offline quigley

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White Polypropylene - the hardest material of all?
« on: April 06, 2014, 04:51:58 am »
I do a lot of medical design work and packaging type products that are made in white. semi transparent polypropylene - think of a plastic syringe/milk carton etc. This is probably the most common material used in plastics yet it continues to ellude the rendering software industry. I have yet to see a truly effective polyprop material. Usually when I do these things I have to spend ages tweaking materials to get the look. This is not helped by the fact that 90% of our work has to be presented against a white background, usually without ground shadows. Ironically, it is far easier to render glass or totally clear plastic objects against a white background than white semi transparent.

If Keyshot 5 has one feature I want it is a good quality consistent, polyprop type material. The existing cloudy plastics are not anywhere near. Tweaking advanced settings comes nowhere near either. This is the one missing element in the Keyshot armoury. It is getting to the point now that I am considering switching all my rendering of these materials to Maxwell which offers decent results (albeit slowly). I noticed I posted a similar request back in 2010:

https://www.keyshot.com/forum/index.php?topic=1134.0

The situation has come to a head becuase I have had to update some complex medical PP visuals I did back with Hypershot 1.5 - something I alluded to in the above post. I am struggling to get anything decent out of Keyshot - artefacts all over the renders.

I have attached the Keyshot package file and a couple of visuals. I'll be going to Develop3D Live and the Keyshot Open day in the UK week after next so I'd like to see what you guys can achieve in Keyshot 5.

(edit - sorry just relaised this is in the wrong Materials section!)
« Last Edit: April 06, 2014, 05:31:00 am by quigley »

Offline quigley

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Re: White Polypropylene - the hardest material of all?
« Reply #1 on: April 06, 2014, 05:18:35 am »
Meant to add that the standard "Cloudy Plastics" in Keyshot often have roughness factors. Adding roughness just creates lots of nasty artefacts in the materials on render - even worse than on the attached. WHat is needed is something that gives a smooth fill like glass but has that milky translucency. FYI this is pulled off the Maxwell Gallery and shows a slightly textured PP material on the spray mechanism - not quite the same but close to what we usually need - ours are usually smooth on the outside. I have also attached a photo of an actual syringe similar to the one in the Keyshot package.

« Last Edit: April 06, 2014, 05:29:54 am by quigley »

Offline DriesV

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Re: White Polypropylene - the hardest material of all?
« Reply #2 on: April 06, 2014, 07:43:39 am »
Cool challenge. I'll give this a shot tonight.

I'll be going to Develop3D Live and the Keyshot Open day in the UK week after next...
I'm trying to get there too. Still looking for a cheap place to stay for 3 nights though. Any tips are welcome! ;)

Dries

Offline quigley

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Re: White Polypropylene - the hardest material of all?
« Reply #3 on: April 06, 2014, 08:24:16 am »
Develop 3D Live has accomodation available at the University of Warwick site the night before. After that I'm not sure but I'm sure there are Premier Inns in the area (Premier Inns are a UK chain of low cost hotels - I use them whenever I travel in the UK).
« Last Edit: April 06, 2014, 08:26:42 am by quigley »

Offline DriesV

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Re: White Polypropylene - the hardest material of all?
« Reply #4 on: April 06, 2014, 08:46:41 am »
Here's my take on this scene.
For rendering I suggest using realtime or advanced with 'Global illumination cache' disabled.
Without GI cache, you won't get any splotchy artifacts in your render.

Attached are renders using both methods (same amount of time) and the KS scene.
Btw, I increased the scale of the rubber plunger a bit, so that in the refractions of the syringe it looks exactly like your sample image.

Dries
« Last Edit: April 06, 2014, 09:06:22 am by DriesV »

Offline TpwUK

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Re: White Polypropylene - the hardest material of all?
« Reply #5 on: April 06, 2014, 08:57:51 am »
Sat here looking at one of medicine syringes here, you're pretty darn close with that one Dries, it's a little too glossy and needs a bit more of a rubbery silicon type of look to it. Good call with the plunger, I was thinking it's inner surface too thick, your trick proves otherwise :)

Martin

Offline DriesV

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Re: White Polypropylene - the hardest material of all?
« Reply #6 on: April 06, 2014, 09:24:33 am »
Yeah, Martin, there's oodles of stuff to fiddle with. :)
I tweaked the material a bit to make it look a bit more like silicon.
My point is: the advanced material is really the one you should be using for PP. You should be able to get at least 95% close to reality, I think.
(image coming soon.)

Dries
« Last Edit: April 06, 2014, 09:57:42 am by DriesV »

Offline DriesV

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Re: White Polypropylene - the hardest material of all?
« Reply #7 on: April 06, 2014, 10:35:28 am »
And here's the result after blending that last render with a 'reflection pass' in Photoshop.

Dries

Offline TpwUK

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Re: White Polypropylene - the hardest material of all?
« Reply #8 on: April 06, 2014, 11:00:17 am »
Yeap, that's about as close as you could get it, well from the one i have here anyway, but mine is just 10ml

Martin

Offline quigley

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Re: White Polypropylene - the hardest material of all?
« Reply #9 on: April 07, 2014, 12:11:54 am »
What can I say? Beautiful work! Give me a shout if you are at D3DLive or the Keyshot day.

Funnily enough, I actually slightly reduced the rubber plunger in size so it didn't contact the side walls as I was getting some nasty artefacts (in the same way you get them with touching clear faces like liquid in a clear container). Now I can switch back to the previous version :)

The trick here seems to be switching the final render to the preview render - so effectively we need to let it sit and cook. Thanks!

Offline DriesV

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Re: White Polypropylene - the hardest material of all?
« Reply #10 on: April 07, 2014, 06:59:51 am »
Quote
Give me a shout if you are at D3DLive or the Keyshot day.

I just made sure that my schedule is clear for next week.
So I'll definitely be heading over for D3DLive and the Keyshot TechForum. :)

Dries

Offline Rydi

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Re: White Polypropylene - the hardest material of all?
« Reply #11 on: April 08, 2014, 12:00:25 am »
Really good job Dries !

thomasteger

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Re: White Polypropylene - the hardest material of all?
« Reply #12 on: April 08, 2014, 06:01:59 am »
Indeed! Is it shared yet? ;-)

Offline Skint

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Re: White Polypropylene - the hardest material of all?
« Reply #13 on: April 08, 2014, 06:59:46 am »
I didn't know about that D3D.   See you there!

Offline Terry

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Re: White Polypropylene - the hardest material of all?
« Reply #14 on: July 22, 2014, 05:15:31 am »
Dries,
I've had the same dilemma for over a year now. Many of our products are made with clear polypropylene and I haven't been able to come up with the right look. Would you be willing to put your material on the new Keyshot Cloud for the rest of us to use? I know there are many of us who would be forever grateful.

Terry