Top-Bottom material - problem?

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  02 February 2013
Top-Bottom material - problem?

Does anyone know what the problem is with the material top-bottom in the image?
3DsMax Design 2012 x64 SP2
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File Type: jpg test.jpg (80.3 KB, 34 views)
 
  02 February 2013
I would hazard a guess that nothing's wrong with it. The vertical faces are confusing it as it's neither top or bottom.
 
  02 February 2013
Check the UV coordinates of the objects where the material is distorted.
 
  02 February 2013
I made a basic elements and only Sphere, Geosphere, Torus and Teapot are correct with top-botom material. Remained as such as an image and whatever I do, I can not get them correctly. I try converting them to poly, mesh and similar but I can not understand am I doing something wrong or it is just a bug.
 
  02 February 2013
All the objects without vertical faces display a correct material(teapot, sphere, pyramid, torus), while where the W coordinates for the texture overlap on the vertical faces(box, cylinder, tube) don't behave correctly because there's simply no space.

It's not a bug - it's a matter of where to determine the border between top side and bottom side.


Have you tried to set the coordinates of the T/B material to Local instead of World?
 
  02 February 2013
It all started as I was from an ordinary plane, made landscape, in an attempt to make the material I could get a top-botom material. I tried a box which then has all three coordinates, two common colors up and down, but only on the spheres are shown correctly. Please note that there is no UVW maps, most common models by default.
 
  02 February 2013
Quote: Please note that there is no UVW maps, most common models by default.

Primitives are uv mapped by default.

2nd time:
Have you tried to set the coordinates of the T/B material to Local instead of World?
 
  02 February 2013
Yes, the same objects are made ​​in the local and world coordinates, with the same result. For the UVW, I meant to say that is not added any modifier.
 
  02 February 2013
You can work around that using a mix material.
 
  02 February 2013
okay I'll find a way, just surprise me with this top-bottom material. Still do not know if this is a bug (for me) or ...
Thanks for your help
 
  02 February 2013
It's not a bug, it's like dividing zero and expecting a result different to zero.
 
  02 February 2013
The top/bottom material is the same as the towards/away falloff with a modified output curve to control the Blend (where Blend 0 has 2 added points in the output curve at [0.5,0.0] and [0.5,1.0], at Blend 100 the points are at [0.0,0.0] and [1.0,1.0]). It is a 90 look up based on world or local z. If you are getting artifacts then as scrimiski said it has to do with the normals of the object, the orientation, and interpolation of the values.

The problem is probably in your object data, or it is how the materials are being calculated by the renderer. UVW shouldn't come into play as it should be based on a procedural falloff.

-Eric
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"The Evil Monkey hiding in your closet."
 
  02 February 2013
Thanks for your suggestion Pixel Monkey ,it is correct. Meantime I was trying something and I realized that if I add the modifier taper for instance, I get the correct top-bottom or blend / vrayblend material. So if I have a flat surface is not good, if they are curved then it is OK. Why, I have no idea.
 
  02 February 2013
PixelMonkey explained why.
Quote: It is a 90 look up based on world or local z. If you are getting artifacts then as scrimiski said it has to do with the normals of the object, the orientation, and interpolation of the values.


On a vertical surface(90) there is no way to calculate where to split between top and bottom.
When you taper the surface you change the angle to something different to 90.
You probably could get away with rotating the element in sub-object mode by one degree or even less.
 
  02 February 2013
So, are you saying that it is not possible to make a top-bottom material at the box model?
 
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