Problem with grass on vray

hetauma · 9 Feb 2010, 19:09

Hi I'm trying to render a scene with vray
I have a problem with a grass material when I apply it on a surface that I made from contours in sketch up (so there is some hidden geometry there)
I used the material "Architectural green grass" (can't remember where I downloaded from)
When I render the image I get some strange lines on the surface of the grass where the hidden lines of the mesh are.

Any suggestions?

thomthom · 9 Feb 2010, 19:18

I'm guessing that there are two faces overlapping each other there. SU some times act up and adds faces double and triple times over.

edu1987 · 10 Feb 2010, 04:48

@thomthom said:

I'm guessing that there are two faces overlapping each other there. SU some times act up and adds faces double and triple times over.

i dont think so thom y had that problem and double cheked if it was a doble face and it wasnt, never could fixed that problem

hetauma · 11 Feb 2010, 00:05

I'm sure that there are no two faces and also that shadow is not an issue.
I have tried deselecting cast shadows and receive shadows and also making Vray not to render shadows and the output is still the same

thomthom · 11 Feb 2010, 06:52

Are their normals flipped? If you set the style to use the default colour only, what does it look like then?

thomthom · 11 Feb 2010, 06:53

Could you possibly save out a part of your model that contain this geometry where it happends - and post it here?

hetauma · 11 Feb 2010, 16:29

@thomthom said:

Are their normals flipped? If you set the style to use the default colour only, what does it look like then?

the faces are right. I see the white side.

I tried that copy part of the model to a new file so I can post it here and when I tried a test render there it renders just fine!
I'm trying to figure out if there is any other geometry that causes this problem now.
I'll be back with any news

davidlouis · 12 Feb 2010, 19:34

hetauma... its intersting that you mention that a copy paste operation seemed to sort out the problem... I have experienced a similar 'roughening effect' of a smoothed mesh with vray bitmap texture assigned to it using the copy paste (to a different sketchup file) function before.

Would i be right in guessing that the surface which has tbe grass texture applied to it was in fact copied into the file from which you attempted to render the final image?... Are you still by any chance using vray 1.05.30?...If so, then this might point to a known bug in which texture info does not transfer across sketchup files too well... in my case for all intensive purposes the vray material properties and soften edge settigns were the same but one rendered smooth and the other rough...

I hear this has been sorted out in the new version... let hope you are not using the new version when this is occuring...

Dave