OTOY Forums

Hi all!


Here's a model I made to continue my modelling and rendering training...
Most of it was modelled in Sketchup (with imports of trees from the SU warehouse, hence the low quality of the trees... ), rest done with Blender.

Please feel free to comment - I need to improve my skills !!!


I'm really looking forward to Octane being able to render Normal Displacement and Alpha Render !!! If you have any tips regarding these aspects feel free to help...
Regarding Alpha Render I thought about doing it manually by turning all the material's Gamma to the full, in order to get the black outlines, and putting a plain white RGB colour in the background... I'll try this and let you know...

For alpha check this, is an easy setup and about the same you suggested http://www.refractivesoftware.com/forum ... 50&start=0 on the displacement do a search, I think Radiance said it won't be implemented in the near future (althou I think he makes a hobby oout of making impossible things happend and surprise us that who knows )
About the render, it's looking good, but the textures need more work, right now you can see them tile, for the grass there is lot's of tricks, if you are going to take all low shots you could go for scattered planes with an alpha map, or if you are going to take higher shots you could try to use poly patch of small grass blades, as low a 1 triangle per blade and throw a bunch of them.
For the tree leaves use translucency with a custom made map of the leave "nerves" it improves a lot the feel of them, check the forum wip also there is a ton of examples.
And finally, are you using pathtracind or directlight?

Thanks for the link regardin Alpha, useful stuff indeed!

kubo wrote:if you are going to take all low shots you could go for scattered planes with an alpha map, or if you are going to take higher shots you could try to use poly patch of small grass blades, as low a 1 triangle per blade and throw a bunch of them.

"scattered planes with an alpha map"... I don't know this technique - could you explain a bit more?


I'm at work right now and don't have access to Octane, so I can't tell you if I used pathtracing or directlighting. I just remember using "daylight" instead of "background image" (or whatever the name is for this in the menu) and checked the "filter" option (the manual says it's better for photorealistic results)
What's best? Pathtracing or Directlighting?

Many thanks for your comments and your help Kubo !!!

here you have a good example http://www.refractivesoftware.com/forum ... 2&start=30 there is plenty more, but from him I got the tip for the texture. Here is the thing, you make a plane with the size of a patch of grass with the same proportion as the image you're going to use, let's say 25x15cm, add the diffuse channel and the opacity one, scatter (repeat it randomly changing scale and rotation) it thru the base grass plane, till you fill densely enough the area, so if your original plane had 2 faces, and you scatter it like 10000 times you'll end up with 20000 faces, not too much for a whole lot of grass, add more in the spots near the camera and less the farther.
The other way is following this tutorial http://www.peterguthrie.net/blog/2009/0 ... al-part-1/ part one and two, it's a more "poly hungry" approach, but gives better results, and once we get instances it's going to kick ass for sure. But if you do your original grass blades with really low polys, like 1 or 3 at most you can crunch quite a few in your scene.
Pathtracing is the more realistic approach, it's the unbiased one btw, and it usually looks much much better, but it also takes more time, directlighing is biased, it looks good, but there is no real light distribution, so it usually looks more bland, yet it gives good images with no time. Also, sunlight looks good, but it has some limitations right now, specially with glass materials, use an HDRI to get very nice results and more interesting light effects, althou I do love neat and crispy shadows that only sunlight can give.
Also search the wip and gallery for grass, you'll see both approaches and different results.
Cheers

Thanks Kubo!

Indeed my computer struggles when I reach over 20-30,000 polys, so these tips should help me but I have to practice.

Many thanks again, I'll post a new pic as soon as I've done some imporvements on it!


Cheers!

Hi!
Here's a quick "grass test" using 1 triangle, scattered randomly using the "Hair" function in Blender.
This technique (although I used only 1 triangle per leaf) is quite "poly-hungry" as you said...


- I UV-mapped the "leaf" that was to be scattered and applied the texture
- I turned into B&W the original green texture, reworked it a bit so that the end of the leaf gradually fades into white
=> I used this as my mixing map as a "floatimage" in the "Opacity" menu
=> I also used it as my specular map (got lazy on that one! )

I made 2 tests: First one using Directlighting with Filter Off
Second using Pathtracing with Filter ON
Without changing any other settings : just to see the difference....
Maybe I'm a bit "weird", but I prefer the one using DirectLighting, whereas (as you said) Pathtracing is supposed to look better...
(or maybe I need glasses! )

Please keep commenting!
Cheers!


PS: both images = 1000 samples per pixel

yeap in this case it does look better the direct one, but that's not usually the case.
Btw, nice one considering just one blade, and I like the texture.

Thanks Kubo!


I'll keep practising and keep you informed!!!

kubo wrote:you make a plane with the size of a patch of grass with the same proportion as the image you're going to use, let's say 25x15cm, add the diffuse channel and the opacity one, scatter (repeat it randomly changing scale and rotation) it thru the base grass plane, till you fill densely enough the area, so if your original plane had 2 faces, and you scatter it like 10000 times you'll end up with 20000 faces, not too much for a whole lot of grass, add more in the spots near the camera and less the farther.

I was wondering...
Using this technique (which is pretty much what I did in the test above), I still end up with lots of polys...
Maybe I misunderstood what you said , but what I did was the following:
- I modelled 1 single blade (a triangle)
- I scattered it on a 25cmx25cm plane (using "hair")
<<at that point I already had about 1000 vertice>>
- I repeated this "haired" plane so that it filled a 2mx2m surface
<<at that point I had tens of thousands of vertice>>
=> I let you imagine the number of polys this would generate for, let's say, a 20mx20m scene!!!

So I wonder if I understood well what you told me...

well, right now like I said is a poly beast, but once we get instances you make a small patch say with 100 or so polys and then you instance it in your scene with no more poly load (well it adds up but no the same as if they weren't instances), Althou I've been able to add quite a few using my gtx260 it all depends of the area you need.
For other cases the plane with a texture, or really large areas, a large texture map.