Z fighting is knocking me out!

Penguin2 · 12 Jan 2013, 15:28

Hi,

Yet another plea for help.

I am still coming to terms with Sketchup and have read up about Z fighting so I believe I basically understand what's going on. However, some of the solutions posted on previous threads don't seem appropriate for what I am trying to achieve.

I have a Sketchup Model of 20 different houses with over a 120 windows (many different sizes). I need to keep the poly count low for obvious reasons. What I am trying to do is apply a simple window with some faces dark grey to represent glass.

I have created my geometry on a vertical face.
'Cut Opening' is checked.
'Replace' is checked.
Glue to vertical.
Set component axis (red & green lie on gluing plane).

Is there any way I can apply these components to the face of the houses without Z fighting.
One post said make the components slightly smaller!! (No not for me)
I also read somewhere to attach to the wall so that it occurs a few mm above the gluing plane. If I have to do that I will go and find the nearest high bridge.

Surely, there must be a simple way of applying basic window geometry to vertical surfaces without this Z fighting.

Any help much appreciated.
Thank you
Andrew (increasingly desperate 'Newbie')!!

PS Have a JPG but I don't think you need to see another picture of this.

Penguin2 · 12 Jan 2013, 15:58

Hi,

Before anyone comes back reminding me that Sketchup is a 3D program I have found a workaround.

I have decided to place the window with a 20mm stand off. This is hardly noticeable and should be OK for me. I haven't applied any textures to the wall yet (probably leave plain colour) but I think what I am doing will be good enough.

I know Sketchup is 3D. The rest of my model clearly demonstrates this. Just feel it would be useful to be able to apply some simple geometry without the Z fighting.

Cheers from a cold and wet UK
Andrew

Wo3Dan · 12 Jan 2013, 16:15

I didn't read anything about having thick walls in your model.
'Glue to' plus 'Cut opening' components can only cut single faces, so if your houses only have the outer shell as a face, then the solution is quite simple.

The loop in component that actually cuts the opening should be "in plane" with the gluing plane (thus in local Z=0 on local R/G plane) The inside face of the loop can be deleted to see the actual cut. All the rest of the geometry that you add to this component is a matter of your choice. So the framing can be 3D, Out of plane. So can be the grey window pane.
All as long as you have that cutting loop (with displayed or hidden edges, your choice) included in the component.

The easiest way to create such a component would be on a big horizontal face. Start with just a single rectangle. Once you have set up this simple component, you can edit it, bringin in whatever you like. You can still alter that rectangular loop to any loop, with or better without filled in face.

cotty · 12 Jan 2013, 16:20

Did you place the component onto a group or a single face (inside the house group)?

pbacot · 12 Jan 2013, 17:55

Post a model with an example of the problem.

Penguin2 · 12 Jan 2013, 19:02

Firstly,

Wo3Dan - Thank you. Sorry but I'm afraid you have lost me a little. I will take some time to study what you are saying and respond later.
Cotty - Before I inserted into my model I just tried placing the windows on a vertical face. I got the Z fighting on that simple installation. The two examples are inserted onto the wall of a group (I did not edit the group) but if the problem occurs with a simple face I expect if I edit group and insert I will get the same result. Will try this though.

My walls are all single faces.

From the attached JPG's the second one has been placed 20mm off the wall face (my quick workaround).
In both cases I;-
Glue to vertical.
Check box 'Cut Opening'.
Check box 'Replace....'.
Set component axis so that red and green lie on gluing plane with blue axis (cross) is perpendicular to red&green axis.

Please excuse might basic description.

Regards,
Andrew

Wo3Dan · 12 Jan 2013, 19:58

@penguin2 said:

...... The two examples are inserted onto the wall of a group (I did not edit the group) but if the problem occurs with a simple face I expect if I edit group and insert I will get the same result. Will try this though...

You may have got the window component correct, but it seems that you placed the component on a face from outside the group. It should be placed directly on the basic face. So enter the wall group and while being in editing context of that group, try again. It seems that Cotty assumed right.

cotty · 12 Jan 2013, 21:05

I've created a little example to show the difference...

Penguin2 · 13 Jan 2013, 15:51

Hi Cotty,

I can't believe you produced the video just for me. So generous with your time.

Also I tried what you suggested. Opened the group and placed the windows whilst still in edit mode. It works!! not more Z fighting.

Thank you Cotty and to all others that have helped.

Regards,
Andrew (Penguin2)