Richard McCarthy Posted June 18, 2004 Share Posted June 18, 2004 Howdy guys... this is just a test rendering for the model I am going to import in from DWG. It is really just a tester to see materials and lighting on a temporary geometry. I have hard time getting the glass to look right under sun light... trying to nail it but still couldn't quite get it to reflect realistically, I have tried Vince_1972's setting, it seems it only makes glass transparant.. when Fresnel is turn off, it become what you see below: Link to comment Share on other sites More sharing options...
Richard McCarthy Posted June 18, 2004 Author Share Posted June 18, 2004 With fresnel turn on..... Link to comment Share on other sites More sharing options...
Ernest Burden III Posted June 18, 2004 Share Posted June 18, 2004 Is fresnel refraction/reflection supposed to make a material MORE like how glass reacts, or less? I know what a Fresnel lens is (used in lighthouses to make light more parrallel (19th century laser, I guess)) but am not sure how it is supposed to work in rendering shaders. There is one in Cinema, and it seems to be necessary for realistic results. I think getting glass right is the single most important shading issue with digital rendering. And so often it isn't right. I still don't know, either, how Lightscape did it. Link to comment Share on other sites More sharing options...
Richard McCarthy Posted June 18, 2004 Author Share Posted June 18, 2004 With "Clear glass" from MAX's own material... This is what I don't get.. how can glass be so hard to emulate? Amazing how lightscape can do so easily, while other renderer needs so much trouble tinkering... Link to comment Share on other sites More sharing options...
Ernest Burden III Posted June 18, 2004 Share Posted June 18, 2004 Amazing how lightscape can do so easily, while other renderer needs so much trouble tinkering... Exactly! I have to get glass in C4D to be as good as that of Lightscape, but haven't gotten there yet. There are some great glass mats posted by STRAT for Cinema, but they still fall a bit short of LS. Now MAX has the 'architectural glass' which is supposed to be the old LS material. If so, then you're there already. Ultimately, the LS glass can't be some super-complex material--LS doesn't have a complex shader engine. So it's probably a simple combination of refraction and reflection and surface. And anyone can make a good Creme Broulee... Link to comment Share on other sites More sharing options...
Ernest Burden III Posted June 18, 2004 Share Posted June 18, 2004 OK, here's a new un-challenge--a simple space with a few glass walls, one frosted, maybe one open to sunlight, to see how different rendering engines handle the glass. If you wait for me to set this up we will all be too old to remember why we were doing it... Link to comment Share on other sites More sharing options...
Richard McCarthy Posted June 18, 2004 Author Share Posted June 18, 2004 Here is some update, from the left : glossiness (reflection) : 0.5 with 0.1 increment til 0.9 is reach. C&C welcome! Which one is your favourite? Link to comment Share on other sites More sharing options...
TheAllusionisst Posted June 18, 2004 Share Posted June 18, 2004 This is a good topic, I don't know how many times I have adjusted the lighting in a scene only to find the glass looked a lot different, so many scene variables to deal with such as angle of view...... Link to comment Share on other sites More sharing options...
Allen Posted June 18, 2004 Share Posted June 18, 2004 I might be off-base here as I'm using LightWave. Fresnel increases relection and decreases transparency as incidence angle increases. I use it in every scene I do - with few exceptions. I find the best way to apply it is using a gradient control in the channels affected. Wouldn't be without it for car bodies and glass. Notice the Z3's windshield is much more reflective and less transparent than the mini-van's - that's due to the angle of the glass to the camera. BTW - where did you get the human models? Link to comment Share on other sites More sharing options...
Chris_Mac Posted June 18, 2004 Share Posted June 18, 2004 This is the glass that I always use, and I've found that as long as there is an environment map, or just something to reflect, it always looks pretty good. I'm using Form Z, so I don't know how this description will translate to other packages. I'll try and keep it as simple as possible. I start with a mirrored material - maximum setting for reflection. Then reduce ambient and diffuse values to almost nothing. Then I use a high specular value. After that, a simple transaparency setting (between 40% and 70%) is all that is needed to give the impression of glass. Because of the low diffuse setting, the colour doesn't really matter, but I ussually use a fairly solid mint hue to give the impression of a slightly green glass. Hope this is of help to you. Link to comment Share on other sites More sharing options...
trhoads Posted June 18, 2004 Share Posted June 18, 2004 To me the most troubling aspect of rendering glass is uniformity between two panels of glass that are right next to each other. In the project I am working on now, I have this problem, and it is the only thing I am trying to fix at this point. Any idea why this is happening. It is rendered in VIZ 3i. Link to comment Share on other sites More sharing options...
Ernest Burden III Posted June 18, 2004 Share Posted June 18, 2004 To me the most troubling aspect of rendering glass is uniformity between two panels of glass that are right next to each other. Looks like a job for Mr. Fresnel! Your glass does not have any variation from angular change, it appears each pane has one set surface reflectivity, probably an average across the surface. Are you using a Fresnel reflection type? Oh, and to the people in-the-know on this subject--what is the purpose of the gradient in the channel with the fresnel setting? Link to comment Share on other sites More sharing options...
trhoads Posted June 18, 2004 Share Posted June 18, 2004 I have to admit, I am not as versed in the terms of the trade as a lot of others. I keep everything pretty simple. I dont think VIZ 3i is capable of using "Mr. Fresnel". I just have AutoCAD solids, rendered with a face map of my glass material. I get this problem in at least one spot on almost every rendering I do. I am at this moment working on fixing it, I am trying a few things, hopefully I can get it to work. Link to comment Share on other sites More sharing options...
Richard McCarthy Posted June 18, 2004 Author Share Posted June 18, 2004 BTW - where did you get the human models? From axyz-design.com 's "Metropoly" collection. I got the free one from them You can also request for a free demo from them. http://www.axyz-design.com Link to comment Share on other sites More sharing options...
trhoads Posted June 18, 2004 Share Posted June 18, 2004 I really like the possiblity of those people. I got the demo, but can not open it. Is it not compatible with VIZ 3i? Which program are you using the model in. Just curious. Link to comment Share on other sites More sharing options...
IC Posted June 18, 2004 Share Posted June 18, 2004 The gradient takes reflectivity from a low setting to a high one in relation to the viewing angle. This is what your fresnel shaders do, and what happens in real life-if you look directly at glass, you don't experience as much reflection as when you angle it away from you. (Not that I'm particularly in the know.) Link to comment Share on other sites More sharing options...
Ernest Burden III Posted June 18, 2004 Share Posted June 18, 2004 The gradient takes reflectivity from a low setting to a high one in relation to the viewing angle. So what happens when you use fresnel and not the gradient? I know, test it and see. Link to comment Share on other sites More sharing options...
IC Posted June 18, 2004 Share Posted June 18, 2004 They do more or less the same thing so I assume you'd get a more pronounced result (?) I get better results using the gradient than the fresnel shader that comes with lightwave. It's flexible and you can copy/paste it into the specular and transparency channels for extra effect. Link to comment Share on other sites More sharing options...
Richard McCarthy Posted June 18, 2004 Author Share Posted June 18, 2004 I really like the possiblity of those people. I got the demo, but can not open it. Is it not compatible with VIZ 3i? Which program are you using the model in. Just curious. I am not sure what version those Metropoly human comes with, but I use MAX6. It also comes with a .obj version which you *might* be able to import into VIZ3i (I am not sure, I never use that version) Link to comment Share on other sites More sharing options...
CRD Posted June 18, 2004 Share Posted June 18, 2004 So what happens when you use fresnel and not the gradient? I know, test it and see. In Max\Viz, fresnel is part of the Falloff map. Falloff can be used to control the amount of reflection based on viewing angle (perpendicular = little reflection, parallel = full reflection). The gradient controls the values for the reflection, with black being no reflection and white being full reflection. So this allows you to fine tune the effect (black to grey, or grey to white, or black to white, or dark grey to light grey, etc.). I figure that this works near the same in most programs. Colin Link to comment Share on other sites More sharing options...
CRD Posted June 18, 2004 Share Posted June 18, 2004 So what happens when you use fresnel and not the gradient? I know, test it and see. In Max\Viz, fresnel is part of the Falloff map. Falloff can be used to control the amount of reflection based on viewing angle (perpendicular = little reflection, parallel = full reflection). The gradient controls the values for the reflection, with black being no reflection and white being full reflection. So this allows you to fine tune the effect (black to grey, or grey to white, or black to white, or dark grey to light grey, etc.). I figure that this works near the same in most programs. Colin Link to comment Share on other sites More sharing options...
Allen Posted June 18, 2004 Share Posted June 18, 2004 Yep. Falloff sounds like the Gradient control in LightWave. The reason I started using gradient controls in my surface editor versus the Fresnel shader was that I started using FPrime as my renderer - FPrime doesn't see shaders so it forced me into gradient controls. Glad it did. The gradients or Falloff offer a lot more control over surfaces than a shader - and to save time on later projects, get a setting you like and then save the surface preset. About the glass problem that started this post...have you checked for modelling problems? Could the problem be non-planar polys or doubled un-unified polys? Grasping here... Link to comment Share on other sites More sharing options...
axyzdesign Posted August 28, 2004 Share Posted August 28, 2004 Thanks for making your tests with my models!! I would also like to invite you to share the works you have done with our products by uploading your images in our Image Gallery. gallery@axyz-design.com Regards, Diego Gadler aXYZ design Link to comment Share on other sites More sharing options...
axyzdesign Posted August 28, 2004 Share Posted August 28, 2004 Hi, I'm Diego Gadler from aXYZ design. Models are compatible came in .lwo, .obj and max. They are compatible with max 4.0 Maybe you can convert the obj or lwo file with a file converter. Regards, Diego Gadler Link to comment Share on other sites More sharing options...
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