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How do I create IES light?

PostPosted: Thu Feb 18, 2016 5:40 pm
by morphious2013
I have the IES profiles, just can't figure out how to add them into octane plugin. Do I need to create an emitter, then ad it in the materials node? If so, where? Thanks.

Re: How do I create IES light?

PostPosted: Thu Feb 18, 2016 9:02 pm
by linvanchene
morphious2013 wrote:I have the IES profiles, just can't figure out how to add them into octane plugin. Do I need to create an emitter, then ad it in the materials node? If so, where? Thanks.


face_off updated the OcDS projection mode names to be identical with the OR standalone version in one of the recent updates.


Now you can follow those steps:

001 Create a Basic Light emitter with the green y normal direction pointing down on the ground.

001 Basic Light emitter.png


002 Change the Distribution setting of the emitter material to a grey image

002 Distribution - change to grey image.png



003 Select one of the IES presets that are shown in the pulldown menu of the grey image node in the distribution setting.

003 Select IES preset.png


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Now you have three options how to proceed:

004A by default the Mesh UV Projection should now be selected

The Mesh UV Projection will create exactly the same light pattern on the floor as in the preview image IF the light emitting plane is pointing with the green y axis normal facing down towards the floor plane.

004A Mesh UV Projection.png


Note that with Mesh UV Projection the IES light pattern is cast directly below the emitter on the floor no matter in which direction the normal of the light emitter is pointing.

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If you want to point the IES light pattern into a specific direction

004B change the projection mode of the IES image in the distribution channel to XYZ to UVW Projection

As Coordinate Space select "Normal Space (IES Lights)"

004B XYZ to UVW Projection.png


Now you can point the green normal y axis of the light emitting plane in the direction you want the IES light pattern to be cast.


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Alternatively

004C change the projection mode of the IES image in the distribution channel to Spherical Projection

As Coordinate Space select "Normal Space (IES Lights)"

004C Spherical Projection.png


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For the sake of it have a look at the pattern with the light emitting plane normal facing down.

Mesh UV Projection.png
Mesh UV Projection


Spherical Projection.png
Spherical Projection


XYZ to UVW Projection.png
XYZ to UVW Projection


Perspective Projection.png
Perspective Projection


-> Spherical Projection can be used to get the same result as Mesh UV Projection.


I guess it is also a matter of preference or creative choice which projection mode you prefer for the effect you want to achieve.


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Also compare:

Projection modes

https://docs.otoy.com/#51Texturing%20Wi ... on%20Nodes

Mesh emitters

https://docs.otoy.com/#51Mesh%20Emitters

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Added the test scene in .duf and .orbx format in the .zip

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Special thanks to Vinz who created, updated and shared the IES presets included in the OctaneRender plugin for DAZ Studio.

originally posted in 2011:
viewtopic.php?f=9&t=6157&start=10#p52161

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Re: How do I create IES light?

PostPosted: Tue Feb 23, 2016 10:32 am
by beat578
Linvanchene: THANK YOU SO MUCH. No finally I understood the IES Settings!
Gonna try that soon.

Re: How do I create IES light?

PostPosted: Fri Feb 26, 2016 8:28 pm
by gaazsi
maybe i should stick on this thread :)

i asked that question to liva already and not even he got an easy answer, but maybe someone else knows... :)

has someone ever tried to "copy" the standard 3dlight conelights in octane? to make it look like in those old but gold 3dlight standard renders? i tried alot but i never got it even close... no idea how to get shadows that sharp and so on...
anyone can provide some hints or adjustments maybe? :) my trial lights have been made from a cone object

Re: How do I create IES light?

PostPosted: Thu Apr 14, 2016 8:26 pm
by morphious2013
Revisited. Should I not be able to "see" the light rays? I only see the surface the light is striking. ???

Re: How do I create IES light?

PostPosted: Thu Apr 14, 2016 8:45 pm
by swipswap
the light needs to be scattered by a medium. if you shine the light through a specular material and attach a medium node, you should be able to achieve rays
in the pictures below i use a primitive cube to serve as fog to scatter the light