Iray and cutout geometry

Steven-V

Hey folks.

I am using the goggles from the Cyria uniform for one of my comic characters, and I have re-colored and re-textured them for Iray. All good.

Except, the goggles have some hinges on them that I really don't want.  In 3DeLight, I just set their opacity to 0 and they never showed up. In Iray, whether I set the cutout opacity to 0, or whether I give it an opacity map that is all black, either way, although the hinges don't render, they cast a shadow.

What can I do to get the hinges not to cast a shadow? Any hints?

Richard Haseltine

Check they aren't set to refract.

Steven-V

They were set to refract, so I turned that off but... still casting shadows. :/

Nothing else seems to be "on" in the various surfaces settings. So I dunno why they are still casting a shadow. It is highly frustrating.

maclean

My method with cutout is to set every channel to black/zero and add a full black map* to the cutout channel. I had some issues with cutout before, but this solved it.

* It must be a full black .jpg = 0/0/0. The size doesn't matter.

Steven-V

Thanks, maclean. I will try doing that.

Steven-V

Well, sigh... I tried setting all the channels that had color values to pure black... pure black cutout map... etc. Still getting a shadow on the glasses.

I am sure there is ONE setting I have wrong. But finding it is the hard part.

Design Anvil - Razor42

You could always use the geometry editor and hide the actual geometry. It's quite easy if the part you want to hide has it's own material surface.

Select Geometry Editor under tools, bring up the Tool settings tab and click the + symbol to select the geometry in the Facegroup, surface or region.

Right click on the Viewport and select Geometry visability and select Hide selected Polygons. 

Steven-V

Huh. Never thought of doing that. I will try it and see what happens. Thanks, DA.

SickleYield

Maybe also double check that the shadow isn't an ambient occlusion shadow baked into the diffuse under the hinge?

Steven-V

I am not using the diffuse maps for the goggles. I re-surfaced everything for Iray.  The frames, against which the tags are showing a shadow, have been converted to white Iray plastic. The tags, I converted to Iray uber but then tried to do the cutout to get rid of them.  I was able to get the geometry thing to work in the viewport. Doing a render right now.

One thing I have noticed. The shadow problem occurs with Sun/sky but not with using a distant light as a scene light, even if the distant light is in the same position as the sun-sky node.

Steven-V

Update:

The Geometry Editor trick seems to have worked. Thanks all!

AnotherUserName

I have seen this happen before as well. I cant remember what surface setting it is that is causing this, but ill research and get back to you on this. Although, Razor42's option seems really cool. ill have to check that out.

AnotherUserName

And now of course, I cannot reproduce the issue...

It was one setting in the surface tab that was causing the issue. One of the buttons. Ill keep an eye out and update when I can.

Steven-V

Thanks AUN.

In the mean time one thing I have noticed... it seems like the Geometry editor visibility has to be reset every time you load the scene, or at least every time you re-start DAZ. I had it working in a scene last night, loaded it today, shadow was back. Re-did the visibility, shadow gone again.  Slightly annoying that the state is not saved across sessions. This means that I am going to have to render everything twice, because the first time I guarantee I will forget to re-do the Geometry editing.

jestmart

Hidden geometry is reset upon loading a scene but any changes or addition to surface zones remain.  If the part or parts you want hidden don't have their own surface zone assign them a new one so you can just select by surface name with the geometry tool and re-hide them.

Steven-V

They have zones and I can select them. I'm just likely to forget to re-hide them.  Given that this thing is going to show up in nearly every panel, at least when the character is in hero ID, it is... frustrating.

But at least I can get it to work now, no more shadow.

Design Anvil - Razor42

You could always delete the geometry instead of hiding it. Then save the item as new version (carefully so you don't save over anything).

Then when you reload your scene it will reference your modified prop instead of the original.

jestmart

Deleting geometry will brake any and all morphs that an item might have so be carefull with that option.

Design Anvil - Razor42

Thats true, sorry I should of mentioned that.