AC22 stair problem

[Mats_Knutsson]

Hi,
Stair has a purple transparent surface cover and I can't understand why. It's not the BM nor the surface. It looks ok in the stair setting window...but in the 3D window...
/M

[Anonymous]

I think this particular color indicates that there is some corruption on the geometry.
Did you use any morph to create the stair?
If so, check if the original morph geometry is ok.
Hope that helps.

[Laszlo Nagy · Accepted solution]

This color usually indicates invalid geometry based on the settings and parameters.

Here is an example: You set the minimum Riser Height for the Stair to 150 mm. Your Story Height is 3000 mm and the Stair is set to be Toplinked to the Story above the Home Story. You create a Stair with 20 steps, so Riser Height becomes 150 mm, the minimum value.
Now, you go to the Story Settings Dialog and decrease the Story Height to 2800 mm. Since the Stair is Toplinked to the Story Height, the total height of the Stair should become 2800 mm, which means Riser Height should change to 140 mm, which is not possible since you specified that the minimum Riser Height is 150 mm. Thus the Stair cannot be generated, so it has invalid geometry and is displayed with this surface color.

[Mats_Knutsson]

LaszloNagy wrote:
This color usually indicates invalid geometry based on the settings and parameters.

Here is an example: You set the minimum Riser Height for the Stair to 150 mm. Your Story Height is 3000 mm and the Stair is set to be Toplinked to the Story above the Home Story. You create a Stair with 20 steps, so Riser Height becomes 150 mm, the minimum value.
Now, you go to the Story Settings Dialog and decrease the Story Height to 2800 mm. Since the Stair is Toplinked to the Story Height, the total height of the Stair should become 2800 mm, which means Riser Height should change to 140 mm, which is not possible since you specified that the minimum Riser Height is 150 mm. Thus the Stair cannot be generated, so it has invalid geometry and is displayed with this surface color.

Ah. Thanks Lazlo! Yes it's invalid but I had no idea the purple colour indicated that. Is it for stairs only?

[Barry Kelly]

Mats_Knutsson wrote:
Ah. Thanks Lazlo! Yes it's invalid but I had no idea the purple colour indicated that. Is it for stairs only?

No, it is for other elements that can link to the storey level as well.
Such as walls where you can link the top of the wall to a storey level.
It is then possible to adjust the storey height so the top is below the base of the wall (i.e. it was a high bulk-head wall).
The wall will now be that pinky/purple colour.
Actually you can change the colour and turn this option off in the Work Environment >On- Screen Options > Use uniform colour to highlight inverted elements.


Barry.

[Laszlo Nagy]

I think if you are using parametric offset modifiers in Complex Profiles, that can also result in invalid geometry:

https://helpcenter.graphisoft.com/user-guide/88577/