Applying decals?

[jones2000u]

There was once a really good tutorial on the web on applying a decal to a shape in carrara - and I've lost it. (I've noticed quite a few have disappeared since Carrara swapped owners)

I want to 'rubber stamp' a logo on to an object without having to designate rectangular layers areas, so I can alter it on the fly with alphas and jpg images (I think I know what I mean).

I seem to remember that it involved a layers list with the top layer as the general materials texture, and the second 'logo' layer with the graphics images set up as mixers. First source is zero, second source is the texture map and the blender is the alpha. All other inputs in that layer are deleted. I think...

Been fiddling for a while and I think I've run out of combinations, because what I've just described doesn't work!

Any answers?

[medeamajic]

With a rectangular layer you can add a different image/logo.

[Toleytoe]

There is a tut. re: "decal" on a mug in 3dxtract June 2004... do a forum search for more 3dxtract info.

[jones2000u]

Hi guys, thanks for the replies

Yes, I have read the tutorials in 3d extract and they are extremely useful. What I was hoping for, though, was a way of applying roughly the same principle to an entire object without first designating a rectangular layer area. Sort of turning the whole object into a rectangular layer, if you see what I mean.

The reason is that: if I could find a way to apply a "floating" decal on to an object simply by remaking the master texture map and alpha, it would speed things up a lot at the shader stage, whereas I find moving the rectangular area and THEN making the shader fit is a bit fiddly and depends on judgment by eye rather than area calculation...

[markbremmer]

To do what you're asking, you'll need to uv map the object and then create your texture maps accordingly, one for each layer. There must some instruction to Carrara about where to place the logo - either via UV map or from a rectangle layer.

An easy way to do it is by simply creating a rectangle layer but then filling it in with a solid color without a texture map so you can see the placement. I've got a free movie about that in my Carrara Dark Arts section at the linke below if your'e interested.

Mark

[jones2000u]

Hello Mark

You helped me before with raytracing - I've viewed/read your tutorials on Dark Arts and 3d extract - I think it's probably about time I repaid the courtesy and coughed up for the CD!

Your answer leads me on to another (related) question. I find Carrara's UV mapping awkward at times, so I downloaded UV Mapper, which seems a brilliant solution BUT it's only half there in the Mac version. I sent an email to them: no response. ...because I would have bought a pro version on the spot if it had existed for the Mac.

Do you know if they still exist, or if there is another similar utility out there?

all the best

[markbremmer]

Hi,

Why buy the CD if you can get it in the on-line format for $30 ;-)

I don't think that there are plans to update UV Mapper on the Mac platform because UV Mapper has been incomplete on the Mac side (as compared to the full, PC version) for several years now.

All UV mapping is awkward at times - regardless of the software. Making things map "correctly" usually has more to do with making sure that the actual geometry of the object is 'UV friendly'.

What kind of object are you trying to map?

Mark

[jones2000u]

well it's more of a general thing. Probably better to explain where I'm coming from: I'm a commercial designer using Carrara for packaging visuals mainly. So artwork for, say, a kid's toy pack is done s/s in 2d, as I know you know! So if I know a cylinder has a height of x and a diameter of n, that gives me the circumference and I can lay down a flat grey area to that dimension (height and circ.), position my artwork correctly in the grey background and then export a jpg at any resolution I want without tidying up any bleeds, stray lines or trims. Then it's really simple to make a white mask over the top, to shape any cut-outs etc, turn the background grey to black and export again as a greyscale alpha. Hey presto - one ready-made parametric shader!

The same technique works for bumps for embossed letters and so forth.

Layers lists allow me to apply decal-style shaders to a general background (the original question). But Carrara produces its UV templates in square format, which distorts the "unpeeled" shape and makes reworking art to suit carrara a real pain in the btm. I would love to use UV maps, but the pain is too great. For my low-level constructions, it's much easier to let the real pack dimension and the real artwork work together. It only falls down when the shape is too complicated/organic to work out the unpeeling in which case I use best guess.

It's a shame about UV mapper - I really liked the friendly way the mapping could be oriented and split. Perhaps I'll get a PC.....er......no.

[Wingnut]

This might help

[jones2000u]

well that was really interesting, wingnut. I wonder if it'll work in Carrara, otherwise I'm going to play with it tomorrow in Hexagon. I wonder if it will do it numerically as well.

Thank you for that tip.

To present my credentials, this is a sample of what I show to clients. Criticism is welcome - it always helps.

This was done with a single back light, a fill light on the backdrop and a side light. No reflectors, no diffusers and no soft boxes. I know the glare on the cap is a bit too much - I'll do it again at some point. And the round halo on the front may get edited out in Photoshop, but it isn't really necessary.

For me carrara's photorealistic rendering is really up to scratch. Just takes a bit of effort to work out the logic of the shaders in real world terms...