Spotlight Definition - Plan Directional Control

[cek]

I've been creating some custom light families and have run across a control issue with spot lights, specifically controlling their direction in a plan view. While it's not really a problem for a round fixture which can be rotated in the rcp view provided a directional arrow is available for orientation, it does present an issue for a fixture with a housing shape that needs to remain fixed both graphically and in rendering, say like a gimbal in a square housing.

Using an angular parameter to control the light source axial direction returns an error and breaks the link when you try and drive the parameter, which is interesting since you can select the light source which will activate the angular dimension (prior to assigning it to a parameter) and manually input the angular values and the spot direction will change, pivoting at its source. Exactly the control I want, but from an instance parameter.

I've tried using a reference line and grouping the spot light source with it and then using an angular control parameter but once you try to drive the parameter the linked group fails.

I find it curious that the program was set up to control tilt angle but not directional angle. I must be missing something because I can't see the logic in omitting such a vital control parameter for a spot light.

I've searched the forums and can't find a response to this particular issue. If there was one I would appreciate the thread link. I've posted this inquiry to the families forum but there is less activity there.

Thanks

[cek]

Ok, wasted half my weekend on this but I've attached a ceiling based family for a light fixture with symbolic lines only and a nested generic annotation family for the arrow.

There is a parameter "Directional Angle" being used to drive the plan orientation. The trick I found was to use a reference line as a rotational anchor. I then used the Directional Angle parameter to drive the spot lights "light source reference" off the anchoring reference line.

It seems the symbolic lines want to anchor themselves in the family environment and don't lend themselves to rotation very easily. They always want to break from their anchors when being driven by angular control parameters. As a result I created the arrow element as a "generic annotation" and nested it within the family.

I then created a reference line with one end starting at the reference planes intersecting origin with its rotation being driven by the same "Directional Angle" to drive the spot light direction. This reference line was used as an anchor for the nested arrow which was aligned and locked to this reference line.

All that's left is to build the family 3D geometry and assign scheduling parameters.

Oh well if I hadn't posted this inquiry I would have never posted the solution. It's only fair that I give as much, if not more, than I have received from others on this forum.

Much thanks to those who have posted useful info. to this forum and to those who were able to resurrect the archives from the dead.

[Ning Zhou]

Carl, maybe i missed something obvious, what's the grouping for? seems it's still working after i ungroup it.