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1) Select Objects/3D-Object/Cube. In the dialog that appears, set theedge length to 200 and make sure that "Separate Surfaces" is notselected. This will mimic the behaviour you'd get on a closed object.Click on "OK" to close the dialog.
2) Apply your decal texture to the cube with flat projection (Frontand Back). Make sure that the "Tile" option is NOT selected. Click onOK.
3) Select the texture icon in the Object Manager, then click on theTexture Tool (middle palette). In the Coordinates Manager, set the Xand Y offsets to 5% each. Set Scale X and Scale Y to 90% each. This stops your texture hitting other surfaces.
4) Render. The picture appears on both the front and back of both opposite surfaces. By all means rotate the camera and render. You might like toadd lots of ambient light to make faces at an angle show up more.
To get the picture on just one of the four mapping surfaces:
5) Double-click on the texture icon in the Object Manager. Change Sideto Front. Render (again, move the camera as required).
This time just *one* of the mapping surfaces has the picture. Why didwe only get it on one surface and not two?
There are two front surfaces and two back surfaces in this example. Anexplanation of what constitutes a front or back surface (I can't usethe word "side" here):
6) Click on the Display Tool (bottom palette), select Options in thedialog that appears, select the "Show Normals" option, then click onOK to close the dialog.
The long, thin red lines show you the surface normals for eachpolygon. The Front of any polygon is the side of the polygon fromwhich the polygon points outwardly. The back of the polygon istherefore the other side (the side which doesn't have the surfacenormal protruding from it).
So, there are *two* front sides involved in our cube example - thesides of the opposite faces that we would consider the outside (orouter surfaces) of the cube.
But often we want the decal on just one of these sides!
So CINEMA 4D has a special rule with flat projection. Notice that thetwo normals for the opposite faces concerned point in oppositedirections. CINEMA 4D exploits this fact so that you can have thedecal applied to just one of the front sides. CINEMA 4D maps the decalonto the front side whose normal is pointing in the opposite directionto the Z direction of the texture (you could consider this the sidethat is facing/looking at the texture).
Make sure that the Texture Tool is still selected (you should see thecyan texture grid). If you look at the direction of the texture's Zaxis, it points in the opposite direction to one of the front sides.This is the side it will be mapped on :-)
So, how do you get the texture on the other front side as well withflat projection?
7) In the Object Manager, hold Crtl down and drag out a copy of thetexture icon just and release the mouse button just to the right ofit.
You should now have two texture icons.
8) Double-click on one of the texture icons. In the Texture dialog,add 180 to the Direction H value.
This makes the texture point in the opposite direction. This means itnow faces the other front side - both front sides now have texturesfacing them.
9) Render - rotate the cube etc.
You can't get the texture on the front side of the opposite face byusing Back, because it is a Front, not a Back! The backs are theinsides of the cube! All of this applies to closed surfaces in general. The cube just makesit easier to demonstrate.
I recommend playing around with the mapping. Try Back, change thedirection of the texture etc.
When decals don't behave as you expect, it is usually one of twothings.
Either:
(i) some/all of the surface normals of your object point in the wrongdirection - surface normals should point outwards from the object, notinwards - you can reverse surface normals using the Structure Manager- sometimes you need to do this with imported meshes or splineobjects/NURBS (depends on how you created them - it's not alwayspossible for CINEMA 4D to know what constitutes the outside of yourobject) but primitives should be fine.
(ii) your texture's Z axis is not pointing in the correct direction.For Front projection, it should point in the *opposite* direction tothe surface normal of the side you want it mapped to (think of thetexture as facing that side - the Z direction of an object/texture isusually considered the direction in which it is pointing, as isevident with cameras, lights...). To reverse the direction of thetexture, simply select the texture axis tool and add 180 to theDirection H value.
I hope this helps clarify things. Any questions, please ask. If anyone's got another way of explaining how this works, please be myguest - it's not that easy to explain, but easy to use once you'vegrasped it!
Regards,
007