CGTalk - problems with alpha map and HDRI reflections

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laiels

11-16-2004, 12:55 AM

Have any of you experienced issues with alpha maps and HDRI reflections?

It seems that whenever I apply an alpha map on an object and I use a HDRI sky object for reflections, the reflections show up on the object with an alpha map on it even though I don't have reflections turned on for that object. Is that the way it's supposed to work? or am I doing something wrong?

Actually, the same thing happens with transparency maps too.

rikke

11-16-2004, 07:38 AM

Do you mean that the whole polygon object is showing in a half-transparent way? Instead of the parts that were actually allowed by the alpha to see?

Then I've got bad news for ya: You can only fix it by placing an object (plane, cube, whatever) between your point of view and the sky/sphere object you've used for hdri reflecions.
Can someone with more experience confirm this?

laiels

11-16-2004, 07:49 AM

I think we are talking about the same thing. But it's more than that, you not only see the entire poly object, but you also see the HDRI reflected in the object, even though reflections are not checked for the object.

laiels

11-16-2004, 08:31 AM

One work around is to use spheres rather than sky objects. Can you please elucidate on how you would place another object in front of the one being alpha mapped?

rikke

11-16-2004, 09:42 AM

I must correct myself: the problem appears only when using skies instead of spheres. I you insist on using skies, you could place a plane with a background picture behind it. (or if possible: an object that is part of the scene

So,point of vieuw->object->plane->sky

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