Directional light with pattern

[AndreasBergmann]

Hello,
tried to achieve an easy to handle barndoor light effect with rectanglular pattern image in distribution node of blackbody emission. Projection mode of image is set "XYZ to UVW" in object space and if I rotate the emitter in octane via transform node the pattern light is following accordingly.

But when I import rotated emitting mesh then beams are not following the normal of the surface. This is strange and should more be like IES files, of course the rays should follow orientation of surface and in workflow I have to import numerous emitting surfaces in my scenes.

Any solutions?

Best,
Andreas

[bepeg4d]

Hi Andreas,
try to change the Coordinates Space into Normal space (IES Lights):

ciao Beppe

[AndreasBergmann]

Thanks for your reply Beppe,
already tried a lot:
here with IES and "XYZ to UVW" projection mode

and here with IES and "spherical" projection mode and some scaling, where the rays follow the surface but the square pattern file is totally distorted/ignored.

I thought the 2nd option could be a solution but now I am wondering why tranforms within Octane work perfect but imported objs are handled so differently - this makes no sense.

Do you have another idea?

Best,
Andreas

[AndreasBergmann]

Hi,
anyone any idea? Would be a great help if this tool works for imported mesh emitters. Really like to get this straight before setting up a new scene. Is this an issue for support?

Thanks,
Andreas

[bepeg4d]

Hi Andreas,
do you mind to scare an example .orbx file with me?
ciao Beppe

[AndreasBergmann]

Hi Beppe,
thanks for asking. Please find attached the associated file and switch between group a and b meshes to see the difference between imported and transformed planes. I also tested with obj instead of fbx but it makes no difference.

Would be great to get some help and to be able to have a patterned light (gobo/barndoor...) like discribed in the manual.

Best,
Andreas

181002_test_light_6.orbx

(189.63 KiB) Downloaded 160 times

[bepeg4d]

Hi,
thanks for the scene.
If you assigne the same rotation of the plane in the projection node, everything is working as expected, in uvw-planar mode, object space, so you need a different material per different rotation:

181002_test_light_6_b.orbx

(206.21 KiB) Downloaded 151 times

ciao Beppe

[AndreasBergmann]

Hi Beppe,
thanks for your reply.
The idea was to test a workflow for an indoor scene with 70+ lights. In the way you described I have to manually extract and paste the x/y/z rotation values for each emitter mesh - a lot of work, am I right?

To me it is the same with IES files - you dont want users to manually type the orientation values of the spherical projection but it should automatically respect the normal orientation of the emitter. To me this would be the right way here too - but IES projection mode detroys the pattern.
Any other way, what you think?

I already thought of a script to automatically get emitter mesh/plane position AND rotation, and generate a transform node for this, you think it is possible?

Thanks,
Andreas

[bepeg4d]

Hi Andreas,
what about importanting the emitter at 0, 0, 0, and then import the positions in .csv for a Scatter node?
ciao Beppe

[AndreasBergmann]

Hi Beppe,
modeling software is adsk alias and auto csv export is not featured. Also I have to do it for every mesh seperately cause I still need individual materials for each light to be able to tweak size, intensity, color etc separately.

I tested the lua script for "Get information from a mesh node" and received XYZ info for position of the emitter plane but do not know if it is possible also to "extract" XYZ axes rotation values and create a corresponding transform node for this. What do you think?

Best,
Andreas