www.kraytracing.com

render grass separtly and post
background integrate with render 80% diffuse

all advice are welcome

thanks

with grass small
is better?
how render a better grass with short time render?

You can`t increse speed render (becouse this is complex obiect) ... But You can use QMC shader 50/0.
I know: nature is very hard to copy...

Nice ambient. Like your ilumination.

I think you can improve so much your image, is poor in details. But nice composition.

Your trying to simulate grass or wild ground? try to add some rocks or wood, and displace the tree on center of image.
Try too to add some more details to break the big and simetric grass, add too some jitter to ground to make more realism

I like the buildings, but for me, the background is too blurry, and the 2d trees don't look very good. The grass just looks wrong. I have a problem with this kind of grass - it is far too even and regular. In reality, most short grass is patchy. There are occasional flowers, weeds and stones. If the grass was this long, then it is neglected, and neglected grass always has weeds

The best thing about this for me by far is the houses.

I know a lot of people are using the instanced grass, but even in the best images it is only just convincing. I think you would have been better off with a good texture map.

Instance grass really takes long. displacements are fast but not as good as real geometry.

bigstickHow about this grass?
http://forums.cgsociety.org/showthread. ... ge=1&pp=15

That's a really nice image and the grass is very good - but only because it has patchiness and variation. It is also a much smaller area, so it is easier to make it look good. It's not that realistic though.

While typing, I am looking out of my window at the grass I cut earlier. It is patchy. there are patches of clover, small areas that I have missed with the mower, and even uneven patches of grass itself where there is a mixture of species, and where people have walked more on certain areas. Most grass has a mixture of species to get softness, ease of maintenance and wear-resistance. So unless you have a very special lawn, like that at a football stadium, you won't get something which looks really even.

Also if you leave your grass so that it is as long as it seems in these images, you will probably get flowers in it.

You can only really identify these things when you look at an image and things don't look right. It's the problem Johny has (or used to have )a lot. The closer you get to simulating reality in a render, the more subtle details your eye will pick up. We have the situation where kray can get such good results, that everyone has to work harder to get a scene that looks real.

So - I'm not quite convinced by this type of grass, and think that a great texture map may give better results.

bigstick wrote: You can only really identify these things when you look at an image and things don't look right. It's the problem Johny has (or used to have )a lot. The closer you get to simulating reality in a render, the more subtle details your eye will pick up. We have the situation where kray can get such good results, that everyone has to work harder to get a scene that looks real.

yes that is so true!

This is no proplem do this on Kray. This is only great idea, we have same tools for do this (except displacement ofcoarse...)

geo_n wrote:Instance grass really takes long. displacements are fast but not as good as real geometry.

bigstickHow about this grass?
http://forums.cgsociety.org/showthread. ... ge=1&pp=15

This is a great job and we can do this whith kray.
If you check this job not have used any special feature of maya or mental ray, all made with real polish... 100,000.000 polys on this secene... amazing scene
If you use real grass whith instance and some trees with instance and remove all 2d vegetation you get similar ambient.
Only need to care so much detail level.

I have attached a photo of my grass to illustrate my point. I have made a seamless version (because I want to use it as a texture) which I won't post because you guys seem to prefer instanced grass

This is fine for open and far grass, but when you need a closed shot , i don´t like to use texture map because you dont have any volume.
For this case , grass is in first plane and can combine this texture with some instance grass and flower, leaves ,rock etc

thanks.
I will do other tests to better understand the nature

bigstick wrote:It's not thatIt's not that realistic though.
So - I'm not quite convinced by this type of grass, and think that a great texture map may give better results.

Please show better grass by texture map. I'm not convinced getting good results from flat texture maps to get good grass like in cgsociety. Even displacement maps has limit to how good they look up close but its necessary for animation.
Johnys grass is almost as good as cgsociety but I discovered long ago instanced grass is good for stills only.

a new step to the improvement of grass
render 2200x960 px
Kray exterior preset
12 h render time! (quad core 12gb ram win64 )
it still looks fake