OctaneRender for Carrara 2.23.0077 [Preview]

Sun Jun 07, 2015 9:49 am

Sorry if this is bombarding you, but this is an interesting example, as the top part (of a sphere vertex object, not a primitive sphere) seems to be behaving normally and the bottom part is uniform in colour. Could it be that only the first X number of polygons are getting properly mapped? (Actually I think I disproved this theory by subdividing the sphere and reapplying the hair, and still the same area was uniform, despite 4 times as many polys).

Sun Jun 07, 2015 3:48 pm

Yes, I see that there is an issue here. The hair colors don't actually line up with the colors on the UV mapped object. I am at the mercy of the Carrara HitTest API but I will see what I can do...

Sun Jun 07, 2015 4:15 pm

Great, thanks for picking this up, I hope that it doesn't cause you too much extra work.

As an interim option, or maybe as an alternative to using the source object, would it be possible to put in a "random UV" option where each strand just gets allocated a random UV position? That would enable the colour variation type usage, although for things like tiger fur, the source UV option is clearly the way to go. I am sure you will get there!

Mon Jun 08, 2015 4:28 am

New update posted to this thread that adds a random UV mapping option.

Mon Jun 08, 2015 7:32 am

Hi Sighman, Thanks for that, I am sure that it will be a useful interim solution, as well as being an extra tool in the armoury longer term. Quick question - can the mapping be changed once assigned? So for example, if I set up an Octane material with the random UV option, can I later change it to Source UV? (or vice versa?)

P.S. It's OK, I have answered my own question, as soon as you change the option it changes the pattern, which is great and very interactive. I thought for a moment that it was assigning colours per segment rather than per hair, but this was an illusion created by overlapping hairs!

That did suggest yet another mode (yes, I know that I am demanding!). Most hair systems (including Carrara's) allow you to choose two colours, one for root and one for tip. If you can assign progressive UVs down the length of the hair (per segment?), this would mimic this functionality. You would only need one direction for this, let's say the V coordinate (= Y axis on an image), then the U coordinate (X on an image) could be randomly assigned. That would give an amazing level of control through using gradients or images as the source of the colours! It would be very exciting (and I think unique) if this were possible.

Mon Jun 08, 2015 11:42 am

Sorry - me again!! I was playing with a style that has two hair groups, and it seems that when you invoke an Octane material for the hair, only the first group is affected, and there is no way that I could see of changing the second (or subsequent) groups. Ideally, you should be able to access each hair group, but failing that, the same material should apply to all groups and not just the first.

Mon Jun 08, 2015 2:17 pm

Unfortunately, you can only assign one UV per hair, not per segment. This has been complained about in the forums and maybe, one day, they will support it. The only way around this is to treat every segment as a separate hair. This will increase the size of the hair model significantly. I can add this as a separate mode but I'm not sure how bends in the hair will render.

Are you using the Edit Shader button in the effect? Each group should have its own shader that should be listed in the drop down of the dialog.

Mon Jun 08, 2015 4:21 pm

Sighman wrote:Unfortunately, you can only assign one UV per hair, not per segment. This has been complained about in the forums and maybe, one day, they will support it. The only way around this is to treat every segment as a separate hair. This will increase the size of the hair model significantly. I can add this as a separate mode but I'm not sure how bends in the hair will render.

Are you using the Edit Shader button in the effect? Each group should have its own shader that should be listed in the drop down of the dialog.

OK, don't worry about the root/tip thing, I remember seeing something about this before and thought that maybe you could cheat the system, but having separate hairs for each segment sounds like a step too far, particularly if it messes up the bending. I am liking the random hair shading system! I think it will be good to keep it even when you crack the UV stuff fully. It means you can get any image of hair and use that as a source for colours, not mapped in any particular way, just to sample the colours in it. Or any image - you don't need to restrict it to standard hair colours!

Thanks for the heads up on hair groups, I'd not really noticed that (I generally use just one group for the whole head). That works fine. I have attached an image (still a work in progress) which shows two hair groups (front and back) and uses the random hair colours.

P.S. Sorry, one more request! Is it possible to add an option to save images as a JPG? It is in the animation dialogue, so I am guessing that it is possible, sometimes I prefer it for test renders and the images are smaller for posting online, keeping PNGs for the final renders.

Mon Jun 08, 2015 4:32 pm

Looks great PhilW. Thanks again Sighman I should get cracking on some testing of old projects that could use this hair upgrade.

Tue Jun 09, 2015 5:43 am

PhilW wrote: P.S. Sorry, one more request! Is it possible to add an option to save images as a JPG? It is in the animation dialogue, so I am guessing that it is possible, sometimes I prefer it for test renders and the images are smaller for posting online, keeping PNGs for the final renders.

Already supported my friend...

: jpeg_save.png (63.12 KiB) Viewed 7477 times