Assigning IES lights to Rhino geometry and retain direction..

[rfollett]

I have asked this question before but never had a satisfactory answer so here goes again!

I want to be able to control the light direction in Rhino..

So I create a small disc/surface and copy x 3 then rotate each disc 90 degrees.. so there normals are all pointing in different direction

Load file into KS (have also tried .fbx but this does not help) - apply IES to discs and they all end up pointing in the same direction.. So I then have to move them all to get correct direction..

surely KS should look at the geometry and work out front and back surface and point light in correct direction??

Thanks Rich

[DriesV]

Hi Rich,

KeyShot looks at the local coordinate system of the part to set the IES light's direction, not the surface normals. The direction of IES lights in KeyShot is always in -Y (KeyShot's coordinate system is Y-up).
The issue here is that Rhino doesn't support local coordinate systems, so every geometry you export from Rhino will always be Z-up (Rhino's default coordinate system).
This is a limitation of Rhino. Full MCAD packages like SOLIDWORKS, Creo etc. do support local coordinate systems for each part, so there rotating a part will allow to control the IES light's direction.

Dries

[rfollett]

Thanks Dries
ok - now I understand - I presume then that no matter what file type I output - none will work because Rhino does not support LCS?

[DriesV]

Thanks Dries
ok - now I understand - I presume then that no matter what file type I output - none will work because Rhino does not support LCS?

Exactly.
File a feature request at McNeel I'd say.

Dries

[Artvps]

I was having the same problem but have a partial workaround for this.

In the right viewport of rhino (z,y view)I selected the entire scene and rotated it 90 degrees to the right. From within rhino I start keyshot with the "render" option. When Keyshot loads up, the model will still be orientated 90 degrees... just select the entire scene and rotate it back to 0. When you assign an ies to your geometry the light will now be pointing down rather than what you are getting. The only thing that doesn't seem to work is if you have any of your lights at an angle, they still point down, so you would have to make the adjustments to individual lights that you require to be angled. 

[DriesV]

I was having the same problem but have a partial workaround for this.

In the right viewport of rhino (z,y view)I selected the entire scene and rotated it 90 degrees to the right. From within rhino I start keyshot with the "render" option. When Keyshot loads up, the model will still be orientated 90 degrees... just select the entire scene and rotate it back to 0. When you assign an ies to your geometry the light will now be pointing down rather than what you are getting. The only thing that doesn't seem to work is if you have any of your lights at an angle, they still point down, so you would have to make the adjustments to individual lights that you require to be angled.

Slightly genius workaround.

Dries

[Artvps]

I was having the same problem but have a partial workaround for this.

In the right viewport of rhino (z,y view)I selected the entire scene and rotated it 90 degrees to the right. From within rhino I start keyshot with the "render" option. When Keyshot loads up, the model will still be orientated 90 degrees... just select the entire scene and rotate it back to 0. When you assign an ies to your geometry the light will now be pointing down rather than what you are getting. The only thing that doesn't seem to work is if you have any of your lights at an angle, they still point down, so you would have to make the adjustments to individual lights that you require to be angled.

Slightly genius workaround.

Dries

More like beginners luck, than genius