We need a proper milky plastic material!

Started by quigley, November 26, 2010, 06:46:11 AM

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quigley

I am doing a lot of medical design work right now and the one thing that crops up time and time again is polypropylene - milky translucent to almost clear plastics in shades from white/grey to all colours. I cannot get a decent result in Keyshot.

I had hoped that the new translucent shader would help this but today read that it does not support visibility of objects behind it. So the typical render of a PP container with a liquid or pills, or a syringe showing the plunger inside is impossible to achieve using this material.

I'm not going to do a "this app does this and this one doesn't" routine here but lets just say that I fired up Maxwell after a long layoff and applied the bog standard PP material from their online material library to a pot, added a green liquid and had immediate results (albeit slow). I then fired up Shot - which is not something I do often - and again applied a plastic translucent material and had reasonable results.

This is one big hole in the keyshot material shaders. What (I think) we need is simple:

Translucent Plastic Shader

Controls:

Diffuse colour
Transparency
Surface roughness
Internal roughness (milkiness)

Please. If anyone has managed to do this please post the settings :-)

Speedster

+1!  This is a nasty material to emulate, and I also am trying, as most of my work is medical.  I've even played with xray in hopes of finding the combo.  I would agree that plastics is the most needed effort right now as more and more KeyShooters are working with consumer and medical products rather than cars.
Bill G

guest84672

As just posted - the advanced material with advanced settings exposed does that. We will show this in the next webinar, too. In the meantime take a look at the webinar we held in July - recording in the webinar section.

ohashi3d

Just trial using "Plastic" material...2 types included (small difference).
Are these enough for you or not!?

quigley

Thanks that is not bad. I have fiddled around with the advanced settings materials as well and that gives slightly more control over surface gloss. I'll try and post some BIPs with the results.

vickyp

can anyone explain to me how you made this material? I'm not able to get it this milky, with me it's either transparant or not, I'm not getting anything in between.

thanks!

guest84672

Turn on the advanced settings in the Preferences. Then use the Advanced material, and change the roughness transmission to a value that is greater than 0.

Oliver

Keyshot is a great product: fast, high quality images, good learning curve and much more, but the material libraries are really letting it down. Any time savings that the easy set-up and fast rendering engine produce are lost by having to sit there and endlessly adjust material properties.

Sure, you've given us lots of controls, lots of buttons and sliders, and if you search the forum one may find a work-around... but that's not how a professional program ought to be run. You've done the hard parts (an amazing set of algorithms, the stability and UI side are coming together, etc.), but why waste resources on silly "vignetting" and "sepia" effects (the most basic image manipulations can do that):

PLEASE invest in the generation of "real" material libraries. For consumer products, incorporating hard and soft plastics, brushed metals... look around your house for inspiration. We need photo realistic materials "on tap"... we know the program can render them!

karl.hewson

It's not obvious (well not to me) but it would appear that changing the Specular Transmission settings to something other than black makes plastic materials translucent.

vickyp

Hi,

is it maybe possible to make a print screen of the settings? I've put the material on advanced and changed the roughness transmission, but it still doesn't look transparant. It becomes very bright white so there has got to be a setting that I miss. Can anyone help me out here?

joshb

Bump.

I'm getting very over-bright white results as well. Seriously, can someone post their settings for a material like this? "Increasing roughness to greater than zero" without further info is a start, but there are a dozen parameters to adjust here...

JeffM

Here's a milky white plastic material that you can add to your library and try out: keyshot.com/images/JeffM/milkywhite.zip

And here's a BIP file from the image below: keyshot.com/images/JeffM/MilkyWhiteClock.zip



The key elements are the specular transmission, diffuse, diffuse transmission, and roughness settings.

Specular transmission lets the surfaces pass light through like a glass. White would be like a true glass, black is completely opaque, between shows like a semi transparent plastic. I set this at about 75% grey.

You introduce the milkiness with the diffuse and diffuse transmission values. These allow light to diffuse on the surface and through the surface. I set these to about 15-30% grey.

The internal roughness makes the surface look frosted on the inside, and the regular roughness setting controls just the roughness on the outer shell of the part.

This material renders much better in realtime, so use the "realtime mode" in the render settings when doing the final output.

Hope that helps!!!

a737

Hi, thanks for the milky material, but I still cant make it work properly. I have a Polipropilene white translucent layer on top of a dull materia ( 2 mm separation)l, so when I render it it appears black/dirty effect. It still looks a bit translucent, but it is not real nor looks like a pp.

My settings are 4 on the shadow quality in the realtime mode and ray bounces 16.... and I am using the milky material posted above.
Does the environment have anything to do?
Need advice, thanks!

justindustrial

I've been struggling with a similar material for a while now. I was trying to achieve a hidden-LED-behind-white PE effect. I tried fine-tuning Brian's(?) LED tutorial to get the effect I was looking for, but could not balance a white diffuse material with translucency. The effect works reasonably well with black plastic, but white fails miserably. The closer I got the material to looking right, the worse the render results were, and for the life of me I could not tweak any sliders to get rid of the speckled effect.



guest84672

Use the realtime render mode for the final render output. That gives you much better results.