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DaneMacbeth
10-10-2002, 06:07 PM
Just a class assignment I had to do for my prman class. My first scene I have created with renderman, quite a nice program :)
Scene is 1 polygon with a displacment map. Enjoy.

Please post any comments/crits !

http://www.yummeh.org.uk/dane/set2.jpg
http://www.yummeh.org.uk/dane/set3.jpg
http://www.yummeh.org.uk/dane/set4.jpg

basti
10-10-2002, 07:15 PM
nice images!
one question: how can a displacement map displace only one polygon? i have to subdivide my objects VERY heavy to get these smooth results! is this a feature of renderman? displacing rendered pixels or something like that?
thanks,
basti :)

pants
10-10-2002, 07:39 PM
hot damn that program is insane.

one hell of a first scene. keep up the good work.

gimik
10-10-2002, 08:13 PM
really nice render.. any chance we could see the displacement map you used? (scaled down, of course--i'd guess the original is pretty big)

Stimpy
10-10-2002, 08:15 PM
Originally posted by basti
nice images!
one question: how can a displacement map displace only one polygon? i have to subdivide my objects VERY heavy to get these smooth results! is this a feature of renderman? displacing rendered pixels or something like that?
thanks,
basti :)

i dont know what software you use, but you shouldnt need to increase the actual subdivision on your model for smoother displacements.. there should be some tesselation parameters for you to increase, so your model gets subdivided at rendertime only, not while actually modelling... so you are working with a light model and still get detailed displacement at rendertime..

and Renderman always had a reputation for its displacement maps..

allows you to generate KICKASS pictures like this one. very nice job.. im curious: what school do you go to ??

Grayson
10-10-2002, 08:17 PM
ok; I'm gonna crit cause I just finished that project too. ;)

When you run the textures through cutter; bump up your blur just a bit to get rid of the stair stepping on some of your rocks.

Also I'm not a huge fan of the background and the Photoshop grain.

Just for fun; here's mine; hope you don't mind. :cool:
Grayson's Renderman Displacement (http://cmpa.ca.scad.edu/faculty/kesson/Ca301/wip/wip_fall2002/ca301.2/grayson_chalmers/pebbles/pebbles.html)

Stimpy: We go to SCAD (http://www.scad.edu/); this (http://cmpa.ca.scad.edu/faculty/kesson/Ca301/) is the class we are taking.

gimik
10-10-2002, 08:22 PM
Originally posted by Grayson

Just for fun; here's mine; hope you don't mind. :cool:
Renderman Displacement (http://cmpa.ca.scad.edu/faculty/kesson/Ca301/wip/wip_fall2002/ca301.2/grayson_chalmers/pebbles/pebbles.html)

how much does using renderman's displacement increase the render time on an image? is it pretty much akin to subdividing your object by a whole bunch (increasing the face count tremendously), or does it take shortcuts?

Grayson
10-10-2002, 08:28 PM
We're still early in the class so I don't know too much.

But renderman takes some crazy shortcuts cause I was sub-sampling my displacements at around .2 and my render times were still under 2 mins.

phoenix
10-10-2002, 08:33 PM
long liveeeeeeeeeeeeeee rendermen!

:bounce:

waiting eagerly for version 10

paconavarro
10-10-2002, 08:45 PM
MAN THATīS freaking awesome!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Grayson that little tutorial about displacementīs great.... you use a heavily subdivided surface I suppouse....?

DaneMacbeth
10-10-2002, 08:58 PM
Grayson, glad to see fellow SCAD students use cgtalk.com :)

Good work on the cobblestone yourself, I just added the background to give the image some substance, although they can look really nice without them, as you have proven.

Here is a link to the different maps that I used to create the image, if you already have not looked through Graysons.

http://cmpa.ca.scad.edu/faculty/kesson/Ca301/wip/wip_fall2002/ca301.4/dane_macbeth/pebbles/pebbles.html

MDuffy
10-10-2002, 09:11 PM
Renderman works a bit differently than other renderers you might be used to. It doesn't need to subdivide the surface into lots of explicit polygons, thus chewing up a lot of memory as the entire scene is subdivided as a pre-processing step (as with MAX, Lightwave, etc). Instead, Renderman breaks the surface into a finer and finer grid as it processes each polygon or surface. When it has broken the surface up so that the grid squares are about a pixel in size on the screen, then it displaces that data. As a result you get very fine displacement resolution without having to have a mesh with a gazillion polygons. Also because it compares the grid to screen size, if the mesh is farther from the camera, and thus smaller on the screen, it doesn't break up each surface as many times. Much more efficient on both CPU time and memory when compared to LW and MAX's approaches.

I'm just now learning Renderman myself. :P Haven't written any shaders yet... looking forward to it...

Later,
Michael Duffy
mduffy@ionet.net

gimik
10-10-2002, 09:17 PM
Originally posted by MDuffy
Renderman works a bit differently than other renderers you might be used to. It doesn't need to subdivide the surface into lots of explicit polygons, thus chewing up a lot of memory as the entire scene is subdivided as a pre-processing step (as with MAX, Lightwave, etc).

makes sense... i figured there must be some kind of procedure it went through--thanks for the explanation. :)

typeA
10-11-2002, 12:38 AM
aww..mom..i wanta class in renderman =[

pluMmet
10-11-2002, 01:40 AM
you two fellas that are using renderman, I have a question for you.

You used 2 or 3 b/w maps. Are they all composatid in Photoshop using opacity layers or do they all go in a different mapping area in RM???

If they all get composited can we see that map also???:bounce:

and also did you just dodge and burn those displacement maps because they look better then my dodge and burns...If you created them another way, please..please..pleasex10 to the 30th tell us how you did them. Or atleast point to a tutorial.:drool:

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