Distorted rendering. Texture maps?

[kentchuang]

Hey guys, the renders I have been doing (vray 3dsmax) have been acting up. It seems like it may have something to do with the texture maps? I'm not entirely sure, but I previously had this problem and I had changed the size of the texture maps which fixed this problem. However, no matter what I do, I still get this distortion shown with the red circles in the image attached. Any one have any ideas what may be causing this problem?

 

Thanks in advanced

[Chris MacDonald]

If you disable displacement, does it still do it?

[kentchuang]

Disabling the displacement in the global switches you mean? Sorry, I am still relatively new to vray still. I'm trying it now on another render which also had the same problem. I'll let you know.

[kentchuang]

Yep. Thanks Chris! Seems to have fixed the issue! Any explanation as to why it would have been doing it? What exactly does the displacement do on vray?

 

Once again, thanks for your help!

[Chris MacDonald]

Displacement is akin to bump mapping, however it actually pushes the geometry out rather than faking the effect.

 

 

Displacement is great for creating small detail that would otherwise be too time consuming to model by hand. There are two ways of creating displacement in VRay; via the vraymtl or the vraydisplacement modifier - the latter giving you more precise control.

 

In arch vis we generally use it for brickwork, tiles, cladding and terrain - but it's entirely up to you how you use it. Like most things in 3D it will impact on render times, but will also give you a higher quality of image/finish than a bump map alone.

 

further reading:

 

http://docs.chaosgroup.com/display/VRAY3MAX/Displacement+Modifier+%7C+VRayDisplacementMod

[kentchuang]

Ahah. Ok I see. So enabling the displacement along with the activated bump maps on the "selected materials" would be the reason certain areas of the render were distorted? Also another question, obviously I am using the displacement wrongly as it is creating such distorted renderings then?

 

Cheers Chris, your help is greatly appreciated!

[Chris MacDonald]

I would imagine so, yes.

 

Displacement works by subdividing the base geometry, so if this is poorly modeled, or very low poly then the computer will have to work harder to achieve good looking displacement. That said, there is no accurate way to control displacement via the vraymtl, whereas the vraydisplacementmod will give you much, much more control.

 

So the first step towards good displacement is good modelling/geometry. In an ideal world you'd want all of your meshes to have a quad topology. However, if you don't live in an ideal world you could use either a quadify mesh modifier, or a tesselate modifier.

 

I'd advise you start with a couple of simple planes, and see how you can achieve different effects with displacement on those first, rather than in a large scene where other factors may cause you issues.