Sigh... Yet another problem...

Fletch · 29 Nov 2007, 23:55

ok RJ, I d/l'd your model, and had a theory it was a SU UV mapping thing... will try some things and let you know. initial tests were inconclusive but not heartening.

Fletch · 29 Nov 2007, 23:57

I have concluded that it's the shape. Unless you can build it in blender, render it, and get it to look any different. I re-built the object myself at large size (50'radius) and very high poly 100 segments per curve, and smoothed in SU)

My tests all show the 'line' you are seeing. If you notice, it's not only on the inside but also around the outside of the shape it is where the normal of the face is no longer coplaner to the inside or outside 'flat' face of the donut. I think that if you were to create this form in real life there would possibly be something similar in it's reflections as well, but perhaps I am mistaken. it probably would be there, but just not as pronounced as in the SU model rendered here. I do not believe this is a KT issue, but perhaps it is, I have been wrong before. I think it's possibly a SU2KT issue, if my theory about the fact the shape is going to reflect light like it is because that's the shape it is.

I lit this in 1 second using an HDRI, I rendered this with MLT preset 7 passes, in less than 4 mins.

I applied a material in SU, then set it to be the diffuse color of the object, set the reflectivity to be 1.0 The material here was not physically accurate, but was to test if UV mapping the object would help. Because the object now had UV coords from SU I was able in KT to go to Window>BitmapCoordinates and change the UV style to Spherical. Later I changed the .jpg map in the diffuse to power of .05, set the reflectivity to .95 (.95+.05=1.0=physically accurate material, properly built for KT) and it rendered like the last picture here. the 'line' you see is still there... but again, I think it's because it's physically accurate to how this object would actually reflect light.

Fletch · 29 Nov 2007, 23:59

in addition, the 'smoothing' of KT only applies to 3ds and .obj models... not models exported with SU2KT... they will use the smoothing from SU2KT's action from SU. If smoothing an object from SU in KT with the r-click-smooth option, results will vary from bad to not-so-good.

Gaieus · 29 Nov 2007, 23:59

Thanks Fletch,

It was driving me crazy, too that I could not find an answer in SU (I do not know as much about Kerky as you therefore I had no clue what and how to change there).

Masta Squidge · 29 Nov 2007, 23:59

I think what the problem is (after reading your great post) is that the radius of the edge is small enough so that it just looks like a mistake. or something to that effect, because it would be there in reality, it just wouldn't be so blatantly obvious as it is in the renders. Your renders make it look normal, while the render i made, at the angle i want it, makes it look terrible.

Fletch · 30 Nov 2007, 00:00

I can ask Clipi and Tomasz what they think. Perhaps Giannis will take a peek, it would be good to get confirmation.

I've only used KT since last October. It doesn't take long to become proficient, but then I had several years rendering experience before that (like 10yrs) and I took to KT like a duck in gold water. Try HDR lighting, it's instantaneous, and you'll like it. Check my latest WIP on the KT forum. to see a building with HDR lighting on it. Then I just mask render in the background (there's a tut. for d/l on the KT home page download sections if you don't know how this is done.)

keep up the great work!