CompuServe Thread

#Another simple (?) quest

4 messages in this thread
#36104From: Peter CampbellFeb 27, 1993 7:13 PM
Hi All, I want to be able to put a decal on a sphere or cylinder and not have it show through to the back side. The object must remain smooth – no seams allowed. How would you accomplish this feat? Thanks. Pete
#36161From: John K. JordanFeb 28, 1993 3:23 PM
Pete, >>decal'n one side of a sphere or cylinder… If you use cylindrical or spherical mapping, and place your decal in the center of a larger bitmap, you can control the placement nicely. I guess you know that if you use the 'Decal' button, you have to pay attention to the upper left pixel and border of the map (pg 9-30). If you make the material as above and use 'Tiled', you don't have to deal with the "upper left pixel transparency" issue. However, your map will be much larger for a given decal resolution and take more memory to render, etc., so it is generally better to make your decal with the appropriate border. Planar mapping will always 'shine' thru the other side on the object level, unless you detach faces into elements. Depending on the geometry, you might detach just the faces that will contain the decal, reattach the faces, and apply your map on the element level. Sometimes it is worthwhile to boolean out a chunk of surface as appropriate to allow flexible material placement. JKJ
#36189From: Peter CampbellMar 1, 1993 2:20 AM
>Planar mapping will always 'shine' thru the other side on the object level, unless you detach faces into elements. Depending on the geometry, you might detach just the faces that will contain the decal, reattach the faces, and apply your map on the element level. Sometimes it is worthwhile to boolean out a chunk of surface as appropriate to allow flexible material placement. John, Thanks for the reply. I tried detaching and reattaching faces as you suggested, and the decal part worked, but the reattached faces were smoothed separately from the rest of the object. I had to weld the object and manually assign all faces to the same smoothing group. Finally, I had what I wanted. Then I discovered an easier way to get the same result: Surface/Material/Assign/Face lets you assign the decal material to the appropriate faces without having to detach them, and without disturbing the smoothing of the object. I sure wish this technique had been included in the manual. Pete
#36277From: John K. JordanMar 1, 1993 8:45 PM
Pete, Glad you got it working! When you weld after detaching/attaching faces, you throw away the 'element' status and end up at the starting point. I like to create separate elements from faces when possible primarily so they will be easier to work with (and to select!). Since there is no way to apply mapping coordinates on the face level, you have to detach faces in order to apply different maps to parts of the same object, eg. wood grain control on the sides of a cube. Even where mapping coordinates are not needed, I find it easier to go back and change materials if working with elements. (I never seem to get things right the first time! <g>) As for curved surfaces – too bad you can't smooth across element/object boundaries, eh? (However, with contrasting materials, I don't think you'd be able to see the edge.) Ain't this fun? – JKJ