Sketch Tool

[alvordr]

I've finally taken an opportunity to try out the sketch tool. It's OK, but what I found is that it treats darker areas as negative space and lighter as positive. The problem with that is that most images you have are the opposite. Sure, you can invert those images, but then if you have an image of a gun, for example..the gun is say, black. The recessed areas are even darker. When you invert the image, those areas become lighter. Now, if you use that with Sketch is becomes a different problem...yes you get the general shape of the gun, but the recessed areas now protrude, instead of recede. Thoughts/opinions/advice?

[AbnRanger]

Photoshop treats black and white the same way, so maybe Andrew is trying to maintain some type of standardization (which I like...I always hated some software that does things differently, just to be different). White is 100% opaque/visible and black is 100% transparent. If you are trying to use a picture of an object, because of shadows and highlights, you're probably not going to get a a decent result. What I did with my XM8 model, is to go into PS, select the background > fill with black > Invert the selection > fill with white. Where you have small, thinner portions, like the trigger, you could select that and give it a shade of light gray. I would also try and fabricate a top view, if you do not have a picture of it....so you have 2 dimensions to fashion your model from.

[alvordr]

I agree and understand. It's not a lighting thing, though when you have indentations in the image object. We see that in your own images there. You physically modeled inner extrusions...am I correct?

[AbnRanger]

Yes. Lighting does indeed matter. Highlights will be interpreted as max extrusions, and shadows casting doesn't provide accurate info, as it only darkens a portion. This is why it's best to take out shadows and highlights (in Photoshop) on Materials one may use to stamp onto a mesh (for color, spec, and depth) in the Paint Room.

[alvordr]

OK, that makes more sense now. I understand. Thanks.

[Eric Cosky]

It would be really useful if Sketch had an option to use greyscale images as a bump map (with minimum/max thresholds) instead of just an on/off stencil so I could paint some elevation details in photoshop before importing it. Or perhaps there is another way to do this in 3DC already?

[AbnRanger]

Just to show what I meant, with a bit more clarity, here is a video by Wayne Robson (Mudbox Evangelist), that may help a bit.

[alvordr]

I use most of those techniques, and they're very useful. Wayne Robson is a great resource for this kind of stuff (digital sculpting, etc.). I have one of his books (Essential ZBrush). It's very good. I recommend it to anyone interested in learning ZB.