Peter Neufeld Posted February 24, 2019 Share Posted February 24, 2019 Hello, I thought I'd share this Renderworks tip but have a bit of nerdy fun first and present the answer after a quick challenge. It's not as easy as it seems and someone showed me this. Can you make a transparent and reflective coloured texture that is also 'shiny'? Like looking through a coloured acrylic window? The shininess is the challenge. I have enclosed a file (although purged is quite large) and all you have to do is to make a texture and render in the default custom Renderworks in the file. The window is an extrude and the texture can be applied by the class 'Acrylic poly window'. There are two saved views both the same; one is in OpenGL the other the Custom Renderworks. Maybe just post snapshots? Cheers, Peter Acrylic Poly Texture Challenge.vwx.zip 1 Quote Link to comment
markdd Posted February 24, 2019 Share Posted February 24, 2019 Transparency also should be the same colour as the Colour shader. I guess it's all in the glass shader colours. I have an edge colour of 80% grey and a centre colour of 70%. I think that perhaps Peter, yours were slightly lighter. Its all a matter of taste! Fun to look at the minutiae and experiment on just one thing for a while. 1 Quote Link to comment
Popular Post zoomer Posted February 24, 2019 Popular Post Share Posted February 24, 2019 (edited) Reflections of all Dielectrics are always white. Only Metals have colored Reflections. All Materials have Fresnel (if not too rough), So the Reflections on the left side of the Window should be more pronounced than on the right Window sides, which you look at nearly perpendicular. A Material will absorb some amount of light. So the sum of Diffuse+Reflection+Transparence should be less than 100%. So I gave it 255/0/0 but only 80% brightness. (The color happens in the Transparency Filter Color) Tried the Metall Reflection Shader with Metal deactivated and Clearcoat only Reflection but saw no Reflection at all so I went classic fake Glass Shader with 100% White (=Fresnell at 90°) / 95% Black (for 5% Reflection at 0°) Edited February 25, 2019 by zoomer 5 Quote Link to comment
Peter Neufeld Posted February 26, 2019 Author Share Posted February 26, 2019 Thanks for trying - very nice attempts. It's actually easier than one might think. Here are the settings and basically the 'secret ' was to use a Fresnel colour shader. Just drop the enclosed texture into your file and have a look. Cheers, Peter Acrylic Poly Texture.vwx 4 Quote Link to comment
mjm Posted February 27, 2019 Share Posted February 27, 2019 I have learned a lot from this thread. 2 Quote Link to comment
zoomer Posted February 27, 2019 Share Posted February 27, 2019 Didn't know or forgot that there is something called Fresnel in Diffuse Chanel. In Reality that should be used for opaque Materials only. Like certain Fabrics or Butterfly Wings. But there isn't any Diffuse in Reality anyway. Just specular Reflection, although arbitrarily in any directions for Dielectrics The Color Tint in the transparent or translucent Acryl would happen in Glass Transparency Channel only. By Filter Color or better Absoroption Distance and Color, to get that Fresnel like Effect of getting more Tint and Absorption when looking through more length or depth of Material. The Plastic Shader in Reflection gives the same Reflection amount for any looking angle, which missies the nice Fresnel Effect of having very low Reflection amount when looking perpendicular to a Face of a Dielectric, versus a very high Reflection when looking at a nearly parallel angle along the Face. Although the Fresnel Effect isn't that pronounced in reality as in my example, with the Fake Glass Reflection, because it only works linear instead of a true Fresnel Curve, where the interesting things happen at the end of the angle spectrum only. So it isn't very obvious or visible if you use a total Fake Plastic Shader or a faked "linear" Glass Shader in Reflection Slot for smooth Dielectrics. Although it would definitely be very visible for a (microskopic) rough Material like Rubber (*) But for a Dielectric, like Acryl is, a Reflection amount of 70% at 90° (because of the "Plastic" Shader) is way too much. Realistic Values would be between 4-6% only. (For all Dielectrics, which don't differ much in 90° Reflection at all) You would see the Problem in Reality with realistic Brightness Environment where the Sky is many times more bright than what you see behind the Acryl in Transparency. Similar if you would use real wide range HDRI Background in a Physical Render. The super bright Reflection would wipe out any visible Transparency effect through the Acryl. A Reflection amount of 70% at 90°, would be a Metal. Something between Platin and Mercury. BTW, Your Plastic Shader Settings have a Roughness value of 70%. You wouldn't see and Details in your Reflections if that worked. So did you deactivate that in your Render Settings somehow, or does the plastic roughness currently not work at all in VW at the moment ???? (I remember a VW 2012 or so feature video where a new blurriness for Reflections on Glass was featured) (*) Semi or non glossy Dielectric Materials. With tiny scratches at a microskopic level, if you have access to semi glossy or matte materials in bath or kitchen like wood, paint or tiles, you can test. Look perpendicular (90°) to the Surface to see no visible Reflections at all, but see strong and super sharp Reflections when looking nearly along (20-0°) the Surface though. 2 Quote Link to comment
scottmoore Posted February 27, 2019 Share Posted February 27, 2019 Wow! That is a lot to think about. Thanks guys. Quote Link to comment
Peter Neufeld Posted February 28, 2019 Author Share Posted February 28, 2019 Excellent dissertation Zoomer thanks. (BTW, who are you anyway - are you really in the Faroe islands?!!). Cheers, Peter Quote Link to comment
scottmoore Posted February 28, 2019 Share Posted February 28, 2019 8 hours ago, Peter Neufeld said: Excellent dissertation Zoomer thanks. (BTW, who are you anyway - are you really in the Faroe islands?!!). Cheers, Peter Agreed on the dissertation. Very informative. Faroe Islands?! Believe it or not I actually did a concert there at Torshavn back in the ‘90s. Beautiful place and wonderful people. Quote Link to comment
zoomer Posted February 28, 2019 Share Posted February 28, 2019 Wishful thinking, nah, its more continental Europe GMT+1 But I am not that really sure as with my Location Settings GMT+1 Windows Time is always 1 hour late (tried both time servers) If I correct manually and reboot its late again. If I trick and choose GMT+2 location - it does GMT+2 (Bug or Purpose !?) So at the end it may be Faroe Islands anyway. Quote Link to comment
cberg Posted February 28, 2019 Share Posted February 28, 2019 This looks better than any of the glass textures I've tried to make. Quote Link to comment
Peter Neufeld Posted March 1, 2019 Author Share Posted March 1, 2019 7 hours ago, cberg said: This looks better than any of the glass textures I've tried to make. Although this wasn't about glass I would very rarely use a glass shader. Unless it's a close up or you're using caustics where the transparency and/or reflectivity needs to be glass. Some tips from the manual: Very clear glass can be set to not cast shadows and thin panes their refractive index should be set to low (just above 1). Often, buildings use glass with a metallic/mirrored energy efficient coating; in that case, a combination of mirror reflectivity and plain transparency can produce a glass effect that renders faster. Frosted (blurry) glass is also to be used sparingly. Here's a render of mine using caustics. Cheers, Peter 2 Quote Link to comment
mjm Posted March 1, 2019 Share Posted March 1, 2019 14 hours ago, Peter Neufeld said: Although this wasn't about glass I would very rarely use a glass shader. Unless it's a close up or you're using caustics where the transparency and/or reflectivity needs to be glass. Some tips from the manual: Very clear glass can be set to not cast shadows and thin panes their refractive index should be set to low (just above 1). Often, buildings use glass with a metallic/mirrored energy efficient coating; in that case, a combination of mirror reflectivity and plain transparency can produce a glass effect that renders faster. Frosted (blurry) glass is also to be used sparingly. Here's a render of mine using caustics. Cheers, Peter Pretty! Was this renderworks? Separate sources for each table object? If so, the DPI and render time on your MacOS / WIN machine I wonder? Quote Link to comment
Peter Neufeld Posted March 1, 2019 Author Share Posted March 1, 2019 Yes Renderworks and separate lights for each one set to high. File enclosed. Cheers, Peter Caustic glasses.vwx.zip Quote Link to comment
mjm Posted March 2, 2019 Share Posted March 2, 2019 21 hours ago, Peter Neufeld said: Yes Renderworks and separate lights for each one set to high. File enclosed. Cheers, Peter Caustic glasses.vwx.zip Thanks man, I'll look at it this coming week. Quote Link to comment
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