Environment texture-how does it work

[dcauldwell_cg]

First of all, I am really pleased with the new release. Its worth it for the implimentation of the alpha channel alone - welcome back transparent png's!!

In stumbling around to discover whats going on with the new settings, I don't seem to be able to get the 'environment' texture to work. This is the one that 'Micha's grass' relied on. When I import 'michas grass' vismat it renders distorted. I think it was based on a cylindrical format, wheras all I can find is the spherical format.
Has anyone elso got this to work? (I am probably missing the obvious!)

David

[edonk]

Re: Environment texture-how does it work

Hmmm I tried this today and got the smae result as you David, Micha are you out there?!!

[thomthom]

Re: Environment texture-how does it work

You sure about cylinder`?
Can't see it mentioned in his article: http://forum.asgvis.com/index.php?topic=2320.0

Bitmap is very large, but the material is sooo simple: only diffuse material layer with texture -> set texture type environment -> horizontal repeat 9 -> ready to use.

[Jackson_cg]

Re: Environment texture-how does it work

David,

Michas method and texture are actually based on the spherical UV mapping type, but as his texture is only a narrow tiling "slice" of a 360° pano you have to repeat it several times horizontally to render properly. Spherical maps are always (or should be) twice as wide as they are high, so you can calculate how many times sliced tiling maps should be repeated by checking how high the image is in pixels, double that figure to get the desired width at max resolution, then divide that by how wide the image is and you'll get the figure that you should put in the horizontal repeat field. In Micha's example this figure is 6.491319444 recurring, but 6.5 is probably close enough. Alternatively, you can open the image in PS, extend the canvas to double the width and edit it to make a 2:1 spherical map which doesn't require repeating in V-Ray.

Jackson

[dcauldwell_cg]

Re: Environment texture-how does it work

Jackson
Very comprehensive reply! Thanks.
I can't double check what I did now, as I have re-installed the previous version of vray, but I am pretty sure I had the repeat set to 9 (as Micha recommended) which worked fine in the earlier vray. Unless someone using the new version can check it out, it will remain a mistery!

Thanks for the replies folks.

David

[thomthom]

Re: Environment texture-how does it work

Old VfSU:


New VfSU:


Result:


Me:
:'(

[40th]

Re: Environment texture-how does it work

Same here. The same settings as before, but it looks like in Thom's image. ???

[edonk]

Re: Environment texture-how does it work

thats exactly how the result was for me yesterday. Interestingly, I also got similar results when trying to displace a grass texture I have, it was almost as if it was displacing it at an angle similar to the result of that texture.
I'm sure there is something really simple we are missing, but until a new manual gets released some of these new features (and old ones!)remain a mystery to me.

[thomthom]

Re: Environment texture-how does it work

In the material preview the horizont looks distorted when I add repeat value. Without I get a straight horizont - but a blurred texture as it's stretched too much.

[Jackson_cg]

Re: Environment texture-how does it work

Hmmm..... that's not good. ???

[dkendig]

Re: Environment texture-how does it work

Yeah, I don't know what's going on. I don't use environment textures much, so I'm going to have to either get Fernando to figure this out and explain it to me, or one of us will just need to get more familiar with this process. Any details you guys uncover would be helpful to know about. I have a ticket about this issue that we are tracking, and it links to this forum post for more information, so just say everything about this issue in this thread please.