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Projector lights

PostPosted: Thu Aug 25, 2016 1:01 pm
by darkline
I see this is doable in cinema 4d but can find nothing about it inside 3dsmax on the manuals page. Ive done a search on the forums too and there doesn't seem to be a default way to do this. Can only find 2 posts which haven't really helped me.

Can someone at Otoy please do a basic tutorial on this? The 2 posts on here show one creating a black pyramid with a light in the top, the other simply using a diffuse texture on a plane with a texture emission. However I cant follow these steps and get anything to work properly. I can get my plane to emit a texture on it's surface fine, but it just emits a gentle colour onto my scene and not an image projection. Playing with the size of the plane and trying random projection modifiers but has not helped me, probably because I'm just guessing at how to do this.

Id really appreciate someone talking through a basic tutorial about this inside max.

thanks

PS why again does this seem so much more simple in cinema 4d? jump to about 24 mins in here...
https://vimeo.com/126014404

In the light properties in cinema 4d there is an option of texture projection - also projection modifiers that seem to work as expected. In max Im create diffuse texture but not getting the same results.

Re: Projector lights

PostPosted: Sun Aug 28, 2016 2:25 am
by rodrigotrovao
dont like max plugin. should have way more tutorials at least.

Re: Projector lights

PostPosted: Sun Aug 28, 2016 11:24 am
by paoloverona
Hi Darkiline,
unfortunately Octane is "famous" for its laks of documentation or tutorials :(
Here is what I do to obtain light projection:
- the plane that casts the image should be really little
- in the emission channel of the material use a "Blackbody emission" or a "Texture emission", they works the same
- use the image you want to be projected into the "distribution" slot of the emission
- set the "border mode" to "Black color" this prevent the image to be repeated or spreaded as it was emitted by a light bulb
- adjust the scale of the projected image using the "uv transform" option of the "Blackbody emission" or Texture emission" channel
thas is more or less all!.

Hope it works for your needs ;)

Re: Projector lights

PostPosted: Tue Aug 30, 2016 11:11 am
by darkline
Thankyou for this explanation. I'm still having a problem however. I can get the image to project but it looks like a spherical or shrink wrapped map projecting now

So I tried adding a slot to the 'projection' parameters and closet I can get is using 'box', however there is still distortion at the edges of my image. What projection did you use in your example?

Jim -can we please have these options in the octane light source please (again like cinema 4d).

Re: Projector lights

PostPosted: Thu Sep 01, 2016 6:34 pm
by paoloverona
could you share the geometry that should project the image? (with the texture)

Re: Projector lights

PostPosted: Sat Sep 03, 2016 1:07 pm
by Goldisart
This question was raised by me one and a half years ago ... but it was ignored

Re: Projector lights

PostPosted: Tue Sep 06, 2016 12:31 pm
by darkline
Hi

The geometry is simply a small plane, casting onto another plane. I've only done it in Max as a test, so no project file. Everytime I do it the projection appears spherical mapped. You have to apply a node to the 'projection' slot to get anything looking normal. Here I've used Box, but there's still distortion at the edges.

anyone any tips?

Re: Projector lights

PostPosted: Tue Sep 06, 2016 8:37 pm
by paoloverona
I asked you the scene (even if it is two planes) just to try to correct the projection and re-send it to you

Re: Projector lights

PostPosted: Tue May 11, 2021 4:56 pm
by coilbook
here is the scene of projector lights in case someone needs it.