i have tried several ways to make a good plastic texture, including following exactly the way given here. i am not happy with any of the results, though i think the principled shader does the best job.
i have a second, more simply technical problem: i am using the blend file given here but my render is out of focus (using B2.79). i thought i would try importing my version of the shaded model truck into a clean and fresh blender stage, but the Append from Library function will only let me import one object at a time, which is really tedious. anyway, if i could find out why my render is so out of focus i would be most grateful.
best wishes, julian darley
Hey Julian, which specific aspect of the plastic's shading are you not liking? I can try to point you in the right direction, but only if I know the kind of result you're looking for.
The camera's focus in the file is attached to the Empty object. You can unhide it and move it around to better suit where you'd like it to be. For no focal blur, set the aperture radius size to 0 in the camera's Depth of Field properties.
hi jonathan, thanks for your answers.
actually, i was trying to imitate the plastic car in your reference photo! my results were not far off yours, but to me, and i know people differ on this, it still looks too much like painted metal. i tried putting in some SSS, a bit of transparency, tweaking the IoR, putting in some Voronoi noise into the normal channel (just a tiny bit), but i cannot get close to the plastic of that car. i couldn't get the tyres to look right either. they keep looking like rubber. i know they would be in real life, but i am trying to imitate the reference image, because in real life, i shall be doing exactly that - even if they are reference images i have chosen. i need my assets to be as photo-real as possible, so i have to be picky. thus, if you can provide with a selection, however small, of different realist plastic node combinations and settings, i would be hugely grateful. i realise also that the model car is full of curves and has ambient lighting and GI reflections, and this definitely makes a difference.
thanks for the solution to my camera DoF problems (which worked as you said they would). i have not looked to see whether you have a camera / render course, but i really need to do that soon!
best wishes,
julian darley
Great questions! To really understand what changes need to be made, the first step is to find out exactly what the differences are between those materials. For this I don't think we'll need anything other than the principled shader and some textures. Take a look at some references online of painted metal, plastic, and rubber.
You'll notice that besides the patterns on the surface, there really are very few factors that are different. In this case, roughness, SSS, and perhaps a sheen or clearcoat on top. Light either gets absorbed, refracted, or reflected by a material, and these settings tell Blender how much of each should be happening. For a deep dive into how this all works, check out these lessons on PBR shading: https://cgcookie.com/lesson/pbr-introduction
Since plastic is a well known substance and our setup is based on its physical properties, there are really not that many ways to set it up correctly. Instead, try adding a grunge texture to the roughness, scratches to the normal, and an indoor HDR texture for the environment. Also be sure that you're using Filmic color management, so that the bright areas don't become oversaturated.
Give that a shot and let me know how it goes!