CoH Graphics

[Joshex]

So. They really did quite well. we can ignore those UV mapping seams in warburg and several other areas when saying this because they were an anomaly. Overall they hit the hardest parts and they hit them well.

This thread is for "how did they do it?"'

In example I just finished unwrapping/texturing a sphere, it was a headache. it's still not perfect, theres a slight texture based seam on the edge thats almost invisible, but overall it's ok. but CoH has round stuff too. And just looking at it wont tell me anything.

Pick a ball like the soccer ball etc. please show me the UV face layout and the corresponding textures. I'd really like to see it.

[SilverAgeFan]

The UVW maps are all over the place.

They may have at times painted on the model which some 3d software prior to closure already allowed and then exported a guide document after getting some registration marks on their seams.

EDIT to add: CoH models are also allowed 1 smoothing group. Faces can be in that smoothing group or out, either all the faces on the model, none or some combination in between. This then tells the renderer to smooth the edges. Without smoothing groups, you end up with something like the quartz models from the DE with hard faceted faces.

[Joshex]

The UVW maps are all over the place.

They may have at times painted on the model which some 3d software prior to closure already allowed and then exported a guide document after getting some registration marks on their seams.

EDIT to add: CoH models are also allowed 1 smoothing group. Faces can be in that smoothing group or out, either all the faces on the model, none or some combination in between. This then tells the renderer to smooth the edges. Without smoothing groups, you end up with something like the quartz models from the DE with hard faceted faces.

I understand smoothing groups, Mechanical objects are usually a combination of smooth and solid rendering.

of course they used exterior software, CoH is not a modelling suite lol. but yeah my question for example, is specifically to see the guide document for a sphere in the game. Is it not possible to pull the UV map from the game to see it? I understand if it's not.

in example heres the sphere I made (left) with the UV face layout(right):


I had to split the object into 2 different materials and 2 different texture sets, though the UVs were stitched together perfectly. is it possible to show a sphere from CoH with it's UV layout next to it like this? even a screenshot would be great.

[SilverAgeFan]

I'd have to pull a sphere from the geos to do that. (Something I honestly won't have time to dig up for a while)

One of the tricks that CoH rendering uses to "smooth" seams further are the "multiply" layers in
a compound texture stack (an "X_ texture" or "trick"). When one of those gets flagged as a "sphere map"
it gets handled differently--projected onto the model dynamically.

This is used for reflections but it also has the effect of burying imperfections, much like "glazing layers" in
an oil painting--if that metaphor makes any sense.

Additionally, there are ways that CoH rendering seems to handle seams of a UV map and geometry back to itself
that blend really well. The asym work I've done I've found it quite forgiving making the vertical seams on the
chest and back disappear (both along the central axis of symmetry).

Where the CoH rendering is much much more finicky is where one geometry picks up the surface of another object.

This may again be connected to smoothing groups and how the graphics engine defines which edges to smooth and how.
Pretty sure CoH uses OpenGL rendering--which honestly is well above my paygrade at the moment.

[Joshex]

I poked around in blender, "sphere" rendering of a texture is possible, it's available in the texture buttons, but not available in the viewport and anything not available in the viewport is not available in the game engine. So thats one thing City's developers did better than blender! though both use OpenGL.

because of that if I wanted to map a sphere I'd need some sort of UVW outline and that would mean seams of some sort. so Idecided that if I have to have seams I should hide them somewhere they aren't likely to be seen from most angles. and the outcome was a brand new Sphere projection method. "Cap Centered Flared".



only has seams at the opposite cap. so it can be swapped with another sphere that has the seams on top if the camera ever falls below the equator. but it sounds like CoH's method is better based off the default OpenGL Sphere Mapping method.