polygons and uv mapping

[mark]

any help below would be much appreciated!

i've always subdivided in houdini because the standard box, either polygon or polymesh, looks really bad unless subdivided. often id rather just bevel and avoid the overhead. hard to explain, it just looks wrong without subdividing. (too) soft edges, lighting looks bad on it.

is there a way i can make a decent looking box and bevel that to look like it does in the viewport in flat shaded view?

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this question is maybe more of a lack of understanding of the concept of UV mapping rather than a houdini question, but here goes..

i think i need to apply to my object a planar projection top and bottom, and a cylindrical on the side.

with a single planar across the top, the UV's look good, and i can export it all as one map for painting on. of course the stretching isnt acceptable. id like to be able to do this technique though, ala texporter in max.

i also tried uvunwrap, but that moved sections of the object into strange places, the one object became 10 randomly places smaller UV sets it would be impossible to paint that correctly.

so i thought id apply the 3 projections, then UVfuse the UV's together... the problem though the UV's became a mess. edges dont line up, and draw lines across the whole grid. it would take me a week to individually move them all into place and be inaccurate, do i really need to do this??

any ideas how i should map this so i can export it to a paint program, preferably in one piece but otherwise in a few pieces but lined up nicely?

[mark]

further to the above.

with polygon modelling ive just used subdivide to smooth. but i noticed the smooth sop! do you ppl use one or the other, or both?

can i do the UV mapping above the subdivide? so much easier to select polygons on the low poly mesh!

[hoknamahn]

To make nice flat look of box you can use a few ways:

1. Uncheck Consolidate Corner Points flag of your Box SOP

2. Use Edge Cusp SOP

3. Use Facet SOP with checked Unique Points flag

How to make object with different projection coordinates? Just apply different UVProject SOPs (with different coordinate systems) to different polygon groups.

If you applied UV coords to object and subdivide them then UV coords must subdivide too (i mean all will be okay )

[mark]

thanks hoknamahn i actually tried facet but without checking the Unique Points flag.. i'll try again.

its great i can do the texturing before smoothing

i can apply the different UV projections, but dont you need to stitch/fuse them together so they line up perfectly? im not sure.. i'll have another go!

cheers

Mark

[deecue]

also on your box shading issue...another approach except edge cusp/facet is to go to OBJ level, in your obj params there is a check box for smooth shading under the shading tab.. check that off and it will look like you want it to without those sops..

as far as your uv's go.. put a layer sop in between each projection and you will have seperate uv's to edit, fuse, paint, etc..make sure you set each layer tho..

i.e. : shader ->uv project->layer sop (set to layer 2)->uv project->layer sop (set to layer 3)-> etc etc..

[mark]

ok thanks deecue some more options. i'll definitely try the layers, and a vex layered shader so i can have my rusty metal and then a chipped, painted layer above it. ill try making the top layer a TGA or similar will the black areas then allow the bottom layer to show through? anyway thats what ill try when i get home to houdini

[deecue]

ill try making the top layer a TGA or similar will the black areas then allow the bottom layer to show through?

it will if your image has an alpha channel..

[mark]

the easiest solution, unchecking Consolidate Corner Points on the box prevents it from being bevelled. box -> -> polybevel -> edgecusp works like a charm.. thanks all i've halved the poly count already and it looks better too

[mark]

ive used deecue's layers tip to add a general colour layer on the object, and then displacement map to selected areas, which is what i wanted.

i thought id try to take it a step further, and do full layered shaders - for example a base metal layer, then another layer of chipped paint. i made the chipped paint layer a TGA with alpha channel. it works, i can see the base layer under the paint layer's holes. but, the base layer is lambert and the top layer is blinn, but the lighting model doesnt come through - the whole object looks like blinn. in fact whatever i do to either layer has no effect (even a huge displacement map on either or both layers). i expect im doing something wrong as a purely diffuse only layer option isnt very suitable...

first is this layered texture idea recommended? it makes sense to me, rather than trying to use a single lighting model, and making a single layered shader in the paint program, then spec maps etc.... i imagine there is more control with fully seperate layers.

but... can an object only have one lighting model, or am i doing something wrong with the layers?