I dont know if somebody already said that but you can put clusters inside groups.
More specific, polygon clusters inside groups. Then you can put overrides in the group and it will affect the polygons of that cluster.
It’s really usefull if you use refmodels and specially overrides. Or if you to expose a group of clusters and apply properties in all them at the same time.
Thanks!
Did you know you can get an instant anemone or tentacly thing by using ONE Extrude op? It’s all about the Transform tab and the number of subdivisions…
See attached screenshot. 
ok thats a cool one:
Drag a model from the browser import it into the scene (duh thats not new).
But if you hold ctrl, it comes as a refmodel 
This one is cool isn’t it? 
Saved me precious time while assembling scenes.
Good one; didn’t know that.
Speaking of holding Ctrl, if you drag a scenefile onto a viewport, it opens, but if you hold down Ctrl when dragging, it merges the dragged scene to the current one. Handy! 
How to select polygons in a checkerboard pattern in XSI:
select a polygon
select menu->select adjacent->polygons
hammer “select menu” button repeatedly with middle mouse button
How to select polygons in stripe patterns in XSI:
select an poly loop (ALT+select 2 neighboring polygons)
steps 2 & 3 as above
When you need to type in specific values in your transform boxes on the right, shift+right click on the ‘scale on all three axis’ button, it turns the boxes blue and when you type in one of them it makes the same value in the other two boxes. Quicker than typing in a value for x,TAB,y,TAB,z…
you can type “1/constraint ID” in constraind blend box - it’s usefull when you have 2 or 3 constrains of the same type on one object to blend - it will calculate correct amount of blending.
don’t know if this has been mentioned before, but just to make sure:
If you need to adjust multiple sliders at once, highlight them (so they turn yellow), hold F4 and MMB click and drag in the viewport.
The same works with a single slider, or any value input.
When using Linear range values,and min value is 0 and max value is 1,
it is enough to type “L” into value field.Same goes for random values “R”.
In any other case, if desired min value is 0, it’s enough to type in “L(max value)”.
So if you constrain objects to curve (path) just type “L(100)”.
If using curve (param) constraint, or whatever, just type “L” in U location value.
In this case max value is 1,so it’s enough to just “L” it.
No need to L(0,100) or L(0,1).Just L(100) and L will do.
This can be used in any value field,of course.
I am new to Softimage, and have to say that these help a whole lot. I am beginning to inch my way over from 3Ds Max just because I love the whole ICE thing. Anyway… Thanks for this huge archive of helpful tips
Probably mentioned but you can easily add or subtract values from a multiselection parameter, ie if you select a bunch of nulls and want to subtract 0.1 from the size parameter, type 0.1-- in the value box. ie: if you have sizes (1.0, 2.3, 4.5) selected you will get (0.9,2.2,4.4) as a result.
0.1++ will add 0.1 to them all.
The more algebric form of -1.0+ to subtract (adding a negation) or 1.0+ (just adding) will also work fine. Of course that applies to all algebric operations, so you can use multiplication (with ), and division by multiplying by the fraction (1/N)
I don’t know if this is actually something “nobody knows”, but the volume effect shader can be used to create a planetary atmosphere. Simple create a sphere slightly larger [about 10%] than the planet itself, and apply a the standard “volume effects” shader to it [fast volume effects won’t work]. Adjust the fall-off so it looks right. There will still be a back glow on the side of the planet that’s in shadow - to fix turn on shadows and set the umbra to 0.
The atmosphere will look choppy where the night side of the planet starts, so set soft shadows on the infinite light you are using as the sun [or planet’s host star] - I usually set it to 5 with 3 samples, and ta-da, a nice atmosphere. Enjoy.
maybe you can post some of these links to hackr too. Would be nice for the design community. https://hackr.io/tutorials/learn-autodesk-softimage
Probably mentioned but you can easily add or subtract values from a multiselection parameter, ie if you select a bunch of nulls and want to subtract 0.1 from the size parameter, type 0.1-- in the value box. ie: if you have sizes (1.0, 2.3, 4.5) selected you will get (0.9,2.2,4.4) as a result.
0.1++ will add 0.1 to them all.