mapping geometric shapes on surfaces with little distortion

Question

is there a simple way to map shapes, text, things like that to surfaces without distortion, or does it come down to cutting the image and fiddling with uvs? the method doesn't need to be game or animation compatible, just straight forward illustration. Below is a quick example. Or think continuous type on walls following the angles of a room (floor, walls, ceiling) I guess i can work it out if you hint me in the right direction. If it's possible at all. Otherwise i'll do it manually straighten the UVs, and deal with seems ;) Thx in advance!

Answer 1

I would use the UV Project modifier.

On the backdrop object just add the modifier. You need to fill out three things (and make sure to check the Override Image option).

1. The image
2. The uv map (does not have to be a pretty UV map, you just need the slot)
3. The projector object. If you use a camera or a spot light as the projector the Scale values will control the size of the texture. For any other type of object they do nothing, the object scale controls the size.

The node to render this are the same as you would use for any image. The modifier is changing the UV map so the image gets rendered "projected."

It works really well (identically to how building projection works) which means you also get the real life "problems," off angle viewing will break the illusion. Also the focal length of the camera makes a difference (it will look perfect with an orthographic camera.)

Answer 2

Overview:

From information you've provided I think the fastest and easiest way (with a lot of control) would be to use Texture Paint with Stencil Image.

I've used black and white image as a Texture Mask, because this method gives more control over color. You can also use any other texture to use it as Stencil.

1. Create new image in UV Editor.
2. UV Unwrap your mesh. It could be even Smart Project, but this could give some glitches sometimes.
3. Go to Texture Paint mode.
4. Under Texture Mask select New.
5. Go to Properties Panel > Texture and choose Brush - Texture Mask.
6. Open your texture.
7. Go back to Texture Mask tab and choose Mask Mapping > Stencil.
8. Now you can place Stencil with Alt+RightMouseButton choose color and paint over it.