In this Blender 2.5 quick video tip we demonstrate how to easily place decals onto your model with empties. This technique provides you complete control over the location, rotation and scale of your decal without the need for UV maps.
Discussion
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Sick!!!(in a good way)
yeah nice i always needet this technique for simple decals on complex meshes thanks !
Gotta try it now , as you always make things look very easy I may get it down, hopefully bit less than an hour
Luckily this one is easy! You just need to be sure you have the axis on the empty orientated correctly.
-Jonathan
Just a little off topic here… I see that there is a book on Amazon with the Williamson name (no first name). I assume this is your upcoming character book… I have preordered already
That is indeed my upcoming book, thanks for the preorder! The details are very sparse on the amazon page right now but that should be remedied soon. Currently the publication date is set to be sometime around August 31st.
Nice Tip, Just on the Pre-Multiply factor, its an interesting issue that comes from different ways to store colours in transparent areas of an image.
For every pixel with alpha on a pre-multipled image, the colour of the pixel is mixed with Black in an equal amount to the transparency. i.e. a white pixel that is half transparent will be stored as 128,128,128,128 rgba. This is how Blender expects images.
For a pixel on a non-pre-multipled image, the colour and alpha are just stored seperately and the colour is not changed when transparency occurs. i.e. a white pixel that is half transparent will be stored as 255,255,255,128. When this type of image is loaded into Blender the edges will Blow out and become super saturated or white. This is how most software like Photoshop handles Alpha transparency.
The reason that Pre-multiplication exists is an efficiency reason back in the days to avoid needing to do the calculations again ad again.
That is the technical reason, if it helps.
Great explanation. Thanks Doug that explains what I was wondering for a long time.
-Jonathan
Very informative, thank you.
Awesome! That’s very cool!
I always liked the ease of decals from the first time i used them in blender (many years ago)
the one thing that would make them really awesome is if you could bake them into the texture
Will the decal be visible on the back side?
Yes, Jonathan mentions this towards the end of the tip.
You can use ‘Clip Cube’ under Image Mapping-> Extension to clip away the back side, it will clip to the bounding box of the empty
Oh that is good to know. Thank you SimonESE
-Jonathan
Thanks, it’s very useful and timesaving feature. Gonna use it in my next work.
Hey wow. so simple yet so helpful. Thanks ^_^
Very cool… texturing is already a massive discipline. This tip is valuable for those wanting a quick effect. If you animate the crate, will a simple parent operation of the Empty to the crate do the trick?
A parent would work perfectly.
-Jonathan
Great Tutorial! Thx.
Normally, if you want to display the Picture only on one side of the cube, you just define a selection area, for the side you want the image to display at. And thats it – you can then use the method shown here to place the decal at any place within that selection as usual.
Keep up that great work, BlenderCookie, Jonathan and Wes!
Nice approach…Very quick and easy.
I’v had seen this issue discussed by Kernon Dillon, some time ago.
Although I didn’t noticed that the image is mapped through the model..
Thanks for the tip.
Quick question: Is it possible to render-bake such decals (I can’t try this myself atm)? If so that might be a good way to place details on a UV mapped image, or at least rough them out for later tweaking in GIMP.
awesome! you explained it very good, and a feature I didn’t know of! never heard even. nice!
Great tip! Thanks!
Thanks for the articles. However, as I’m trying this for the first time, on Blender 2.56a, I cannot get the empty and image mapping to work correctly together; for some reason the image mapping is not aligned with the Z axis of the empty, but with that of the camera !
As there are also artifacts on the rendered image in different amount at random times (with the exact same transformation of everything) with the default scale of the empty, I’m guessing this is one of multiple bugs with the beta (as should be expected), but I have no idea.
Hi there,
Can you send me a screenshot of the issues you’re having with the empty? Then I can try to help you a bit more, particularly with the artifacts.
-Jonathan
Thanks for the reply. But it seems I don’t have the projection problem and artifacts anymore.
FWIW the artifact was that while most of the image (like I mentioned before) was projected along the cameras Z (or Y?) axis (meaning the projected image faced the camera/observer), the nearby zone on the faces adjacent to the vertex nearest to the camera was rendered as if the image was projected along the empty’s Z axis (that’s upward).
I hope I explained without causing confusion.
Update:
The artifact is apparently tied to rendering in new window as opposed to, for example, in the uv/image editor.
Question – if you apply this to a rigged, animated object – how do you keep it in the same spot? For example, if the box in the video was rigged and dancing (like a box of cereal in a commercial, lets say) how do you keep that decal in the same place? My attempts have the decal frozen in the same spot, whilst my mesh moves around.
Awesome stuff.
I guess to have a decal on a rigged animated object (that is moving around) you must parent an empty to the object to get the decal to move with an object?
actually, I discovered this the other day – you need to parent the empty to the bone on your rig, then it will stay where you want and it will move fairly accurately
I followed this guide verbatim and it doesn’t work AT ALL
Hi Richard, what isn’t working?
Hey, i cant add empty objects nor lattice it apears greyd out and cant select it.
Make sure you’re in Object mode when you try and add the Empty.
Hello Jonathan, your tutorials are excellent, parabens, I live in Brazil and the lack of good materials like yours, do us a great lack.
What is the possibility of you making (or translate) tutorials in Portuguese?
Thankful.
luis
Hello Jonathan, your tutorials are excellent, parabens, I live in Brazil and the lack of good materials like yours, do us a great lack.
What is the possibility of you making (or translate) tutorials in Portuguese?
Thankful.
luis
unfortunately none of us here at the studio speak Portuguese, if you go to http://www.blender.org/community/user-community/ and scroll down to Brazilian (Portuguese) there is some tutorial sites that may benefit you
-Alex
hi,is there a way to do it in cycles?