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Iggy
07-30-2003, 03:57 PM
What I want to do is very simple. I have some small labels that I'm modeling. They are the engraved style, where a top layer of plastic is cut away in the shape of the letters to reveal a contrasting text color beneath. To try to make this very simple I'm making the text in photoshop with an alpha channel to mask around the text so that the plastic texture of the label shows through.

What I would also like to do would be apply a bump map using the text image that would make the text appear to be cut away in the label. I thought for a while that this was not possible, but in my experimentation I made it happen. Unfortunately, I changed some things in the photoshop file and this bump effect disappeared. I don't know what I did or how to make it come back! Now when I have the image in the bump map channel I get just flat text on a render. When it worked it was very clear that it was set right, and it looked great.

This is a very minor piece of my model and not particularly important, but I want to understand what is happening here. I'm obsessed with the learning curve. All insights are appreciated.

Iggy
Iggy
07-31-2003, 02:08 AM
No one has any insights on this? How to make something alpha masked show up on a bump map? For one brief shining moment I had it, but now it's all gone! I was having a little trouble getting my alphas straight in Photoshop (I'm fairly noob there too) and I probably made something wrong that turned out oh so right... Please if anyone knows a trick I needs it!!
AdamT
07-31-2003, 04:51 AM
Hi Iggy,
I'm not 100% sure what you're dealing with. Any chance you could post your material somewhere so we can have a look?
Iggy
07-31-2003, 01:10 PM
Okay, here's what I've got. Here's a render of the original image in Solidworks.

http://www.mechanolatry.com/images/cgtalk/Overpack-Pressure-Swx.gif

You can see that it's cut away. Works quickly in Solidworks, but in translation it turns into a *ton* of polys, so I thought I'd work up a quick replacement.

Here's the replacement in C4D. No cutaway, just text masked with an alpha channel and superimposed on a texture. (Forgot to bold the text, so it looks a little different.)

http://www.mechanolatry.com/images/cgtalk/Overpack-Pressure-C4D.gif

I was fooling with the alpha channel in Photoshop (I was confused for a little while about which color defined opacity and which transparency) and the alpha color setting in C4D. I was also adding and removing a color background behind the text in Photoshop. Somewhere along the way I hit a combination that allowed me to use a bump map with the Photoshop file as the image reference and rendered as if the text was cut away from the label. It even showed up in the editor looking that way. But I accidentally changed it and don't know what combination of elements made that work. I would really like to discover it again, as this could be a very useful effect. Here's the scene file and photoshop image for any who want to fool with my elements. But any alpha channel photoshop image will work.

Scene File (http://www.mechanolatry.com/images/cgtalk/Pressure Label.zip)

As always, all help is most sincerely appreciated.
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