[Andy]

Here's a quick hack that allows you to specify the distance for an extrude.

in tcl/ac3d.tcl, find:

    } elseif {$draw_mode == "extrude"} {
        setting_title $object_detail_frame "Extrude parameters:"
        set s1 [setting_spin $object_detail_frame prefs_extrude_num "Sections" "number sections in extrude" 1 999 3]
        set s2 [setting_bool $object_detail_frame prefs_extrude_cap_end "Cap end" "Cap the end of the extrusion?"]
		set s4 [setting_bool $object_detail_frame prefs_extrude_flip_cap "Flip new surfaces" "Flip the direction of the new surfaces?"]
		set s3 [setting_bool $object_detail_frame prefs_extrude_delete_original "Remove original" "Remove the original surfaces?"]

after that, add:

        set s5 [setting_edit  $object_detail_frame extrudex "x" "X distance" 3]
        set s6 [setting_edit  $object_detail_frame extrudey "y" "Y distance" 3]
        set s7 [setting_edit  $object_detail_frame extrudez "z" "Z distance" 3]

		set eb [cbutton $object_detail_frame.extrudenow "Extrude now"  {ac3d extrude_dist $extrudex $extrudey $extrudez } "extrude now with the above distance"]
		pack $eb

This adds three fields after the extrude params, along with a button that does the extrude.

(could do with formatting the xyz fields in a row but you get the idea.)

Andy