Refraction question

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• count23361 Posts: 781Member

  July 2007 #2

  

  There isn't really any refraction textures, you just need to put a slight transperancy on your objects, make them double sided polygons (since when you look at those, you are seeing both sides of the divce through the refraction.
  
  The net step is to just go on google and search for "refraction table plastic" and look for red plastic. There is a universal standard for the refraction of plastic and you shouldn't need a map to get that effect.

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• IcyPenguigo0 Posts: 0Member

  July 2007 #3

  Thanks! I'll give that a try.
• tobian226 Posts: 1,600Member

  July 2007 #4

  

  Yep, index of refraction is basically how much the light bends when it passes from one substance to another 1 being nominal, and usually 2 being the upper end (normally) Most common materials fall somewhere between that Index of Refraction here's one I googled!
  
  The other issue you have is absorbtion, and refraction blur, you'll have to check on how those work on your software though. You also need to have reflectivity, a Fresnel gradient on reflection (plastic is reflective!) and or specularity
  
  Another tip is you need to get something TOO refract, and reflect. Don't be fooled by that image, those are cutout, they probably have background things which are being subtly reflected and refracted, to give them that depth and colour. Sticking them on a white background with a single spotlight will make for very boring renders!
• IcyPenguigo0 Posts: 0Member

  July 2007 #5

  I'm not sure why, but I'm not getting any results:
  
  
  
  All I've done with it so far was make it translucent, made the polygons and the material 2-sided, and increased the index of refraction to about 1.5. I'm sure there are things I'm doing wrong(or haven't done), but shouldn't that be basically enough to get a refractive effect?
• count23361 Posts: 781Member

  July 2007 #6

  

  you'll need a reflection as well as refraction, and probably high gloss, remember this is a shiny surface and plastic does reflect as well.

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• tobian226 Posts: 1,600Member

  July 2007 #7

  

  Hmm, erm, not sure here but translucency isn't the same thing as transparency. translucence is just the property of light transmittance through an object, such as a light inside a lamp, lighting the inside of lamp, and passing through the fabric to make it glow on the outside.. You need transparency.
  
  Also, not sure about your app, but in LW, you have to activate 'raytrace refractions' otherwise... nothing happens So check your render setup/settings to make sure such an option is activated!
• count23361 Posts: 781Member

  July 2007 #8

  

  thanks for catching that tobian, i knew something wasn't right about his object.
  
  Icy, you need to have transperancy, like i said above, that's the point of having the double-sided polygons, so you dont "see through" the object as much as "see into". I should have clarified that more when i explained it.

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• IcyPenguigo0 Posts: 0Member

  July 2007 #9

  Thank you guys for your help so far. I've got the refraction effect working. It looks pretty bad, though:
  
  
  
  Any suggestions on how I can finesse it and make it look more natural? I don't know if this helps you guys, but I am using 3D max.
• MadKoiFish9834 Posts: 5,333Member

  July 2007 #10

  

  uh, regular materials will not do anything like this. You need to use a raytrace material and proper settings in max.
  I would google tuts on ice or glass effects. I have only done this in brazil a 3rd party renderer. As well a object needs to exist in the enviroment to reflect bounce etc. Not to mention distort.

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• count23361 Posts: 781Member

  July 2007 #11

  

  ok, so it's half working, you've got the refraction and transperancy about right, you just have to work on the materials now. I'd follow madkoifish's suggestion now and google for ice or particularly "stained glass" windows. stained glass effects are closer to what you need.

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• MadKoiFish9834 Posts: 5,333Member

  July 2007 #12

  

  Here is a quickie
  Max default scanline renderer
  Use raytrace material uncheck the basic parameters colour boxes use the #s instead
  apply use settings as follows
  Diffuse your color
  tansparencey 49
  index of reflection 1.1
  spec 100
  gloss 70
  under super sampling check box enable local supersampler (this should elimanate any jaggie ness that the default reflections have. IF you havent messed with the AA in the renderer menu. Then place a plane for it to bounce crap around in. The index of reflection setting is the distortion in the objects shape.
  
  NOW this shows a HUGE flaw in max scanline it doesnt treat objects properly how light transmits through things. I think this is called caustics. Reality there would be hotspots under the object as well as other changes in the shadows due to the light passing through the object. Maybe if I used ray shadows instead of area shadows it would work. But I have in the past just resorted to brazil (sadly its not a free renderer) But play around with it.

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• MadKoiFish9834 Posts: 5,333Member

  July 2007 #13

  

  Ok heh raytraced shadows with ray bias under ray traced shadow prams turned up to 5
  
  Not 100% but it should get you in the right direction, I dont think the scanline renderer can do the hotspots that should existin the shadows.

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