[Tan Boon Meng]

Hi all,

How do i get to render this 3 images at the same time?
Imagine a scene with an apple on a ground. I need to render the Shadow, Apple and the Apple Alpha. Everytime i tried, all i can get was the shadow, the apple together with the ground and a white image, i cant get the apple alpha. What i did was checking the "matt shadow" for the ground texture, and with the "render" "shadow" and "alpha" checked on the render options, channel. But the alpha image is all white. If i checked the "matt" on ground texture, the shadow will not turn out.

Regards

[WillMartin]

Your question is more a general Maxwell question than a LW plug-in question I think. Maybe a mod will move this over for you?

I haven't done much alpha rendering myself. What I do (think I) know is that sky will always alpha-out, so maybe try to get rid of everything around the apple (except emitters), see if rendering that gets you your apple and its alpha isolated at least. I know that's not "all at the same time" but maybe it's a start for you? That's all I can offer for now.

[Eric Lagman]

Only way I know is you will have to do your shadow pass first with everything showing then kick off another render with floor/backdrop hidden to camera by checking the hidden to camera checkbox in the object properties. For the second render just check alpha as your render channel pass so it only has to calculate that and not a full render. I have request in the past making a check box for an object that says hidden/exclude from alpha so that this could maybe be done in one step, but this is the only way I have seen it done in the past and done myself. Maybe there is a new feature in 2.0 that I am not aware of.

[Tan Boon Meng]

Hi WillMartin and Eric,

Yes, by removing or setting the surrounding objects to matt will render out the alpha (apple). But in that case i need double render. I dont use the standalone Maxwell, so im not very sure does it behave the same way as what im rendering from Lightwave. So now what i did was to render the color from maxwell, but alpha will be using Lightwave to render (faster), but it doesnt apply to all scenes, example objects in Maxwell with displacement map. Just wondering why it doesnt work in just one render.

Regards