Grass to look real when rendered

Raylectron (http://Raylectron.com) is a 3D rendering engine for Trimble Sketchup (http://sketchup.com)
Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Grass to look real when rendered

Post by Nick1 »

Hi Michael,
In Sketchup the grass material is applies to face and it is only a texture. Is there a way to make the grass look real when rendering it so you actually see blades of grass instead of just a texture? Is there a displacement function that one can use in Raylectron? And if there is or there isn't do you know of a work around?
Thanks much,

Nick

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Hello Nick,

You can try with the bump level (2 maybe), but that's not the same as a displacement map or an elevation map. However, you could download the free Fur plugin which can create grass blades...

http://forums.sketchucation.com/viewtopic.php?t=28092

Look a few pages down, it show a terrain made of grass, and it looks so real when rendered.
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Thanks Michael, I already had the plug in however whenever I used it the model would get too big. Maybe I have to try it again. The bump doesn't do much for rendering purposes unless you have a way about it. Displacement implementation would be a nice feature to have for exterior or sometimes even interior rendering.
Thanks again,
Nick

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Yes indeed, displacement & elevation maps are on the works.

The trick for grass with the Fur plugin is not to make it too full, and use the same color for the ground it's in, because most of the time, you will see the grass from the side, not from the sky.
Your support team.
http://SoftByteLabs.com

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Nick, see my tutorial in the forum about how to make realistic/natural grass. Here is a render output, very little poly for the grass...
Grass.png
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Michael,
I followed your tutorial and might have made a mistake somewhere. I just wanted to test it on a simple model. Attached are two images of the rendering and the Sketchup GUI. Where have i gone wrong?
Thanks
Nick
Attachments
grass1.jpg
grass.jpg
grass.jpg (51.71 KiB) Viewed 29849 times

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Doesn't look like you've done anything wrong Nick. From this view angle, you need to add more density, and also, apply a grass texture to the plane itself, or you will see the gray ground in between the grass! Take a look at my screen shot above, you'll see a bald spot on the bottom right, that's the gound texture, not the grass component. Also, do not use Ambient Occlusion as your light source, use Sky of anything else!
Your support team.
http://SoftByteLabs.com

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Nick, here is a sketchup model for you to try, and a screen shot (path traced, sky only, 2 minutes)...
Attachments
Grass.png
Grass.skp
(1.23 MiB) Downloaded 1299 times
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Michael,
Now I am more confused than before and would appreciate it if you can educate me on this.
1- you mentioned to apply a ground texture to the face, then you mentioned to give it a grass texture. This is where I am confused. How can I apply two textures to a face? The bald spot makes it even look more natural but I think I need to be spoon-fed on this.
2- When I do the model and create the grass face, do I still have to go to tools menu and reverse faces?
I'll try the skp model you sent me and see how you did it.
Thanks again,

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

ok, you have a face you want grass on right? That's the face to put a ground texture to so that you have a good match when viewing between the grass blades. If you leave it white, then your grass will show all those white spots in between the grass blades. For example, draw a rectangle, say 16'x16' and apply a green color to it. Then, select that face and crowd it with the grass component, and that's all there is to it. No need to apply a texture to the grass blades because the grass component already have the grass PNG transparent image assigned to it, which is what makes it look so real.
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Michael,
I looked at the model you sent me. I am still confused. You have the stone group model, within it you have the Fur plug in applied to the grass textured face. Where is the ground texture in this model?
Thanks,
Nick

Ok now, so the ground material can be either a grass texture or even a color. Am I right? If so then what was your ground color/texture in your original image which also showed the building, in other words what was the name of color/texture that you selected for the ground material?
Also the few bushes you have on the left side of the image, are those from sketchup or your own library?

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

That's right, you got.

I used the Sketchup Vegetation texture (Lanceolate) and sized it to match about the same as the grass blades, because as a default, it's too big. But like you said, you can use anything, color and all. It's whatever effect you like.

The small bushes are from the 3D warehouse, they have plenty of 3D trees and bushes.
Your support team.
http://SoftByteLabs.com

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

No wait, the ground texture on the one with the house was Vegetation_Maple
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Michael,
Thanks again. Still the same effect of the grass laying flat. Here are two images along with the skp file itself. I used groundcover-sand-smooth texture for the face since I didn't have Vegetation Maple. Where did you get that texture? From the 3D warehouse? I used 100 for the density and so on and rendered it and here are the images.
Attachments
grass-2try.skp
(1.82 MiB) Downloaded 1016 times
grass-SU-GUI.jpg
grass-2nd-try.jpg
grass-2nd-try.jpg (31.71 KiB) Viewed 29838 times

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Looks good Nick. The Vegetation_Maple is from Sketchup. Look at he Vegetation drop down list, almost at the end.

Here is your skp file with the texture I used on the ground and the Maple one on the wall. You can extract then. And a quick 1 min render...
Attachments
Nick.png
grass-2try.skp
(1.87 MiB) Downloaded 1140 times
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Michael,

thanks again for modifying my model. Your rendering shows the middle of the grass area, and since you say that what I did was right, then I am assuming that the edges would render flat as it shows on my previous render. So If I am not mistaken, again you used the Vegetation-Lanceolate as your ground material and you also applied the Maple one on the wall for my usages so I can extract the texture. Thank you so much.
Am I right though in assuming the edge effect of being flat(almost horizontal) as opposed to vertical or standing up?
Thanks again Michael, I'll do another test. I don't really know the details of your rendering settings for this but mine will be much more than 1 minute.

Ok. I rendered my revised model that you sent me with Path tracing, enable shadows and sun and sky. Can you please tell me if you changed any of the render dialog parameters or let me know exactly waht settings you used? Here is an image of the rendering I made from the middle of grass also in 4 minutes.
Attachments
Nick.jpg
Last edited by Nick1 on Mon Jul 16, 2012 6:46 pm, edited 1 time in total.

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

The edges on your model were vertical Nick. But you don't want the edges in the render or it will not look good. That's why mine isn't showing it, and the other one had a stone border. You can also move move each individual ones that are outside the perimeter, into the perimeter.

I used path tracing, Sky and no other settings. But I use 8 threads, not 4, and the view port set at 927x512. If you use an environment map, it'll look way better, because in real life, there are trees, houses, cars, roads etc. In Sketchup, it's empty space, nothing to reflect or shade from!

Also, you can scale the grass component prior to "Fur crowd" it if you're going to view the grass at a distance and want to make it taller etc. Scale while preserving the aspect ration, do not just stretch it.
Your support team.
http://SoftByteLabs.com

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Here is another render of the grass, the same as on yours. Notice that the camera is closer to the ground than in the sky, so the blades are more visible. Click on the image to view it original size.
RaylectronHouse.png
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Michael,
Here another try at it using camera closer to ground. I also did path tracing and only sun as you said. I don't think view port size makes that much of a difference for such a small space rendering, neither 8 threads vs 4 threads which I think only speeds up the rendering and not the quality unless I am dead wrong. Your rendering looks nice and bright and your setting was only path tracing and sun. So was the one I did, and it is the same skp model. Are there any nice free environment map sites that you recommend? Would it be too much to ask you for the Environment map you used for your rendering to see if it makes any difference in mine?

Also what do you mean by scaling the grass. I think you mean the SU texture edit dialog.
Also, you can scale the grass component prior to "Fur crowd" it if you're going to view the grass at a distance and want to make it taller etc. Scale while preserving the aspect ration, do not just stretch it.
Thanks Michael,
Attachments
Nick1.jpg
Last edited by Nick1 on Mon Jul 16, 2012 7:12 pm, edited 1 time in total.

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

Nick, Sky, not Sun! and I also forgot to mention to set the Sky intensity to 2 in the Render option window :oops:
Your support team.
http://SoftByteLabs.com

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

oh, anf tone mapping br=-3
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

Here are two more shots. The one with dark background was done with path tracing and sky only with the sky intensity set to 2 as you mentioned(3 minutes). The second one also path tracing, but sun and sky together with the sky intensity set to 2 also, rendered for 10 minutes. I guess I'll have to try it with your environment map and set it to sky only to see if I get the same sharp rendering result(s). As you see in the second rendering even after 10 minutes the blades are not showing much even though the camera view is quite close to the ground. I am about few trail and errors away before I throw out this computer out of the window. :evil:
Thanks Michael,
Attachments
Nick4.jpg
Nick3.jpg

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

The first one like perfect, that must be the Sky setting. The second one, has to be ambient occlusion, no sky, no sun, because as soon as you turn on the Sky, the blue sky will be rendered, and this one is a black sky. When you load an environment map, do not set it at Sky, it will automatically be set to Environment.

So whatever settings you did for the first one, is correct. Just load an env map and re-render, you'll see how nice it'll look.
Your support team.
http://SoftByteLabs.com

Nick1
Posts: 181
Joined: Sun Jun 10, 2012 9:40 pm

Re: Grass to look real when rendered

Post by Nick1 »

What I did for the top image(the bright one) was path tracing, sun and sky together. The one which has a dark background was path tracing with sky only. In both, the sky intensity was set to 2. The only ambient setting I found was Ambient Shadows under ray tracing mode. So where do I disable Ambient Occlusion?

User avatar
Support
Site Admin
Posts: 1883
Joined: Sun Oct 02, 2011 10:49 am

Re: Grass to look real when rendered

Post by Support »

If you have selected Path tracing, then there will be no ambient shadows. Maybe you selected Sky but forgot to click on Apply? I do that sometimes!
Your support team.
http://SoftByteLabs.com

Post Reply