Toon Paint-outline Problems -- Carrottop Bug?

[kerrytouch]

Hi,

I have created an object and have applied a toon shader to it, and an outline shader too.

I render it and all is well, when i render with motion blur on. the toon shader blurs ok, but the pfxtoon line does not.

I even tried it with the sample CarrotTop. Same thing happens, toon outlines are not blurred, and are misplaced. (ie not on the geometry, as it "moved" being blurred)

In my example in the pfxtoon attribute, i did make sure motion blur was on, bit still no luck.

I tried to convert it to polys, but again, i thought this might work, but it does not seem to. strange??

I would rather not convert if i dont have to, but if its not operational that i will (grudingly)

some do this step 1 ...step 3 would be great (thankyou)

Please any help here would be very gratefully accepted.

Kerry.

[duncanbrinsmead]

Motion blur is not directly supported on the toon feature. However you might try using 2D blur instead of 3D. Also this will tend to work better if you convert to poly. One of the problems for motion blur is the profile, which can change in topology as the object moves. Motion blur samples the mesh at different points in time and then determines the interpolation. This does not work properly if the triangulation of the object is changing between these samples.

However note that the "offset mesh" style profile line will motion blur correctly in both 2d and 3d. Also pfx to poly for crease and border lines should motion blur correctly.

Another solution is to render sub frames and composite the subframes together with an pixel average composite operation.

Duncan

[kerrytouch]

Hi & thanks Duncan for that answer.

I did try those things you mentioned, but stangely the convert to polys, still seems to have a problem, esp when you extend the "blur by frame" from its default 1 to say 5 or larger (exaggerating the blur effect, exeragerates the misalignment too).

I have tried this in both 2d and 3d, I did do a bit (1 day) of testing to see what did and didn't work before I posted, I think you should always "do the homework!"

Strangely if i take the polys and "reduce" them by 50% and delete history, that does have a better (closer effect) it seems as if the "convert to polys" is still holding some information. that the blur does not like.

I noticed that "offset mesh" does seems to produce the right effect, but due to the characters, I cant assume that I will be able to use this all the time. But it does do it.

You said, "One of the problems for motion blur is the profile, which can change in topology as the object moves. Motion blur samples the mesh at different points in time and then determines the interpolation."

Surely, before the effect of MB is done, ie the movement of the fractional frame, the post effect (toon outline) is "frozen", ie converted into poly's for any further operation that happens. So when ever mb sampled it, it would be right. But if i was smart I suppose I would realize that you didn't do it this way, for some reason, as you wouldn't have mentioned the above. But I can think why you didn't?

Your other solution for rendering sub-frames and then comp them in, does work, but I has hoping Maya would do it for me. My philosophy, is that the machine is better at it than i am (faster too)

Penultimately, its, just a pity that the results are what they are, as the idea of the using toon like carrot top, to produce animated (rather than still) clip's what have blur on them all inside maya to me would have been a winner. But that said, congratulations on what has been achieved so far.

Lastly, but not least, I would like to thank you for a clear an lucid answer, as well as the answer itself.

Kerry.

[duncanbrinsmead]

It might be worth noting that if you freeze frame on classic Disney animation the outlines do not have motion blur( stretch and squash is a sort of stand-in ).

At any rate the maya render engine evaluates geometry at fractional frames for motion blur. The geometry evaluation triggers a line generation, which may result in different topology. Note that one can also animate the topology of objects in Maya through other means, and motion blur will suffer a similar fate. However it might be worse for the toon profile lines, as the direction and start position of the line meshes can change, which would result in huge blurs crossing the object.

The convert to poly should be OK for blurs on non-profile lines, as these are fixed over time(providing you don't use "local occlusion"). You should probably turn off motionblur on the profile line mesh to avoid the occasional large bad blur. Or simply do the profile with the pfx lines. A 2D blur from the surface could catch much of the profile.

With 2d blur you could potentially save the blur vector file from a render with a profile mesh outline, then apply the blur using these vectors to a non-blurred render with your preferred linestyle.

Duncan