poly modeling and vray

[archotect]

I've been modeling my architectural scenes by using the poly modeling technique. this means 1 model will include windows, frames and skin as a multi sub-object. this also makes the glass a single plane.

so my questions are as follows:
1. is vray actually less efficient with multi-sub objects?
2. glass, i hear that vray glass needs two surfaces. is this true? does it incease render times with a single plane?

thanks.

[joconnell]

1. Not in my experience no.
2. Glass does - If a ray goes into glass, it must come out again or everything will look like it's trapped in a volume of glass and everything looks really bendy. Same way as thin flat glass like a car windscreen has barely any effect on vision, whereas a solid sphere of glass warps everything to a large extent. You need to have your view go into the glass and out again to look correct, or alternatively make your glass have no refraction at all by setting your ior value to 1.0. Please note that ior also affects the reflections unless you have their settings unlinked.

[RErender]

just a note: an ior of 1.0 can in some cases cause issues, better to use 1.001.

[joconnell]

Good to know.

[archotect]

okay, i just ran a couple of test renders and see what you mean, the glass with 2 planes looks much better. the 2 plane glass is on the left and 1 plane glass is on the right. in test 1 ior is 1.6 and test 2 ior is 1.001. you can see that the plane also distorts the objects behind with ior of 1.6.

http://www.garywatson.ca/GLASSTEST1.JPG

http://www.garywatson.ca/GLASSTEST2.JPG



looks like i will have to modify my modeling technique.

thanks.[/img]