How toget rid ofthis Poly?

A quick consolidate operation at the end will also reduce the polygon count <!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>

I am making a series of 18 cutouts in a NG flatcar deck to allow clearance for U bolts that attach pieces of rail under the side sills. Am doing this by Object Subtracting a sized cube primitive from the deck.

16 of the 18 cutouts are good but two of them have a darker color Poly shape extending from the cutout. This Poly also shows as a darker area after the surface is textured.

What the heck is causing this and what can I do about it? Am using Pro 6.5.1.0

Thanks in advance, Bill

Unfortunately, subtractions are not always flawless. It may help to undo the one that has an odd face sticking out and shift the subtracting cube slightly.

Re-creasing may help with the darker faces.

A closer view of the face that’s sticking out could help.

Also try the Repair Object Geometry operation.
If I’m building something like this that will need quite a few cut outs,I find it better to create these ‘cut out’ faces in the model from the start by building with series of extrudes. It takes a bit longer but works very well.

Bazza

Got it working by creasing and shifting. Thanks for the rapid response.Is there a SIMPLE explination as to what caused the problem and what creasing did to fix it?

Bazza,
Your suggestion sounds interesting but afraid it is way over my head. <!– s:( –><img src="{SMILIES_PATH}/icon_e_sad.gif" alt="" title="Sad" /><!– s:( –> Would like to try it though if you have a reference or can give me a few pointers. <!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>

Thanks, Bill

Bill

My guess i that there were some colinear edges which in 6.5.1.0 causes this sort of shading problem (the Crease operation adjusts shading). I don’t think this would happen in 6.6.5, but I could be wrong.

This is harder to explain than to do <!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt="" title="Smile" /><!– s:) –>
See the attached pic…

A) Start with a flattened cube…extrude the Blue)outer faces.
First to give you the red faces, extrude again to give you the yellow outer edge.
Next select all the green faces and extrude by the width of the cutout you want.
Change the amount of the extrude to give you the area between cutouts…continue till you end up with something like C.
D)Select all the faces you want to cut out…do a negative extrude and delete the face.

Hope this makes some sense..what you end up with is a model with much tidier geometry than using the Object Subtraction.

Bazza

And the 3DC file…it’s in Feet and Inches and not to any scale. You’ll have to zoom out a bit.

Bazza