View Full Version : Baffled with mask for label

05 May 2009, 09:09 AM
I am modelling up a simple fire extinguisher with a label wrapped around the cylinder body.
Have been using a cylindrical shape for the label map, and then a Standard material with label image plus an Opacity map to limit the visible area. This works fine, as only the label portion is visible...

... however when I make the extinguisher cylinder (slightly smaller in diameter) visible then the 'translucen' or 'masked out' area of the label casts a shadow. Please see attached.

None of my lights in the scene use Cast Shadows (yet), and I am using the Light Tracer.
The label's Object Properties have been set to not cast a shadow. This is Max 5.

Any input hugely appreciated...

05 May 2009, 09:18 AM
Can you please mark those areas and repost the image??? because what you are saying is barely visible in the image or I am really not understanding your problem.....Solution can be found easily I guess.......

05 May 2009, 09:37 AM
Hi almightie. Gladly.

I have attached two further images: one a screenshot from the interface where you can see the area of the cylinder which as been masked by the opacity map; and the second points to the part of the red cylinder body where the masked part still casts a shadow.

What I mean is that the area that has supposedly been allocated as see-through still blocks light.

I hope this makes some sense. Thanks.

05 May 2009, 09:48 AM
I actually dont remember max5 lighting parameters because its been a long time I've work on that version...currently I am working on Max 2009.....So I will not advice you anything on technical part of your lighting system (though I know that advance lighting only considers transparency value of 0 and 1 any value between that will be consider as 1 and will cast shadow)

So if your label is still a tube you can use slice on and slice the unwanted part (please check in your version that slice modifier is available there? ) and then adjust your texture by rotating Gizmo of your UVW modifier......Try with this and let me know.....all the best

05 May 2009, 10:04 AM
Sure - cutting or slicing part of the mash works in a rough way. The problem is that the mask has rounded corners, and that is not something that is easy to duplicate for a slice. This means that the four corners still 'cast a shadow' on the red cylinder (which will of course be much larger than it appears in the attached thumbs).

05 May 2009, 10:31 AM
Here comes the actual problem......can you please give little detail or screen shots of your lighting setup and material setup ? that will be helpful as I dont remember technical parameters in your system is drastically changed with each newer version of 3Ds max.....Other solution is....Save your file with different name> convert your label to editable poly and select all four corners and Chamfer it...I doubt that your version of max has facility to add segments value in to chamfer tool....

try to add omni light with ray traced shadow ( or use ray traced shadow in you existing lights) and try....

Sorry for taking long conversations in place but its all about version of the software....also try to send screen shot of your lightig setting if possible

05 May 2009, 11:03 AM

Max 5 using Scanline renderer and Light Tracer lighting.
Three lights in the scene plus a skylight. None of these are set to cast shadows.

The red cylinder is a Raytrace mat - and come to think of it the problem is more likely a case of reflection of the masked area off this than that of a cast shadow. But still... should the invisible area of the label reflect back?

Some attachments of the setup...

05 May 2009, 11:29 AM
I guess the skylight is causing problem.....remove skylight (because skylights dont have support for ray tracing) and try adding ray trace shadow in one of the light ( the one facing the label) and render the image.....

I dont have max on my current system as I am out somewhere.....If its not working out properly then I will post specific solution according to your light setup in next few soon as I reach back my place.....

Update the post after following these steps.....

05 May 2009, 11:53 AM
I think you've got it almightie. It's the skylight causing the problem.
Will adjust the scene to run without it. Thanks for you help here - appreciate that. :thumbsup:

05 May 2009, 12:03 PM
good that the problem is now solved.........


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