conflicting coplanar faces

[gmac]

new guy here. In a discussion about rendering time, someone asked about faces occupying the same space and its made me gasp if what I did is the problem.

As an example I have a number of conditions where I created (SU a footprint of a framing area for example and made it a group, the extruded it. then made a footprint in the example of an adjacent brick veneer in the same manner. Even if grouped, is it a problem that those two hidden sides are coplanar? I had left the groups as as groups and never went in and deleted the common surfaces

If so, that explains a lot of my problems and will cause me to spend some time in fixing it. (big model).



-GM

[thomthom]

Re: conflicting coplanar faces

I've never been bothered about faces like that - not unless they are visible in the render...

[fpedrogo]

Re: conflicting coplanar faces

If the overlapping surface are expose to the camera, you will have some issue, but if the overlapping surface are hidden, like in your sample, you should not have any issue. If you are using transparency material, like glass, and the surface is overlapping with other, you could get sampling problem, thus more render time, more memory usage.

[fpedrogo]

Re: conflicting coplanar faces

If the materials are the same, probably you are not going to see this weird issue, but the render time will be more.

[fpedrogo]

Re: conflicting coplanar faces

Here is the same example, but with glass material.

[thomthom]

Re: conflicting coplanar faces

If the materials are the same, probably you are not going to see this weird issue, but the render time will be more.

oooh....... I often have glass components side-by-side...
I take it that even a slight offset, like 1mm, would be enough to avoid slow-downs?

[fpedrogo]

Re: conflicting coplanar faces

I take it that even a slight offset, like 1mm, would be enough to avoid slow-downs?

yes, 1mm is enough.

Best

[thomthom]

Re: conflicting coplanar faces

hmm.... I might need to write a script....

[fpedrogo]

Re: conflicting coplanar faces

Could be a good idea.
As you see in my first example, if the coplanar face are hidden, V-Ray doesn't have to throw sampler there and you have no issue. The problem is when you have transparency material or when the coplanar is exposed to the render.

[gmac]

Re: conflicting coplanar faces

ok, that's really helpful. (the example). If nothing else, its probably better to get in the habit of dumping the extra faces. I stayed with this last night and cleaned out hundreds of them and actually noticeably affected the overall file size. if nothing else it makes it more readable in xray mode.

I'm working on getting the model posted. ...coming.

thanks you guys! Really appreciate that this group is so willing to pitch in and help. - Greg