Sidefx forum reply on "VOPSOP & Shader Problem"
Had this issue where the embossed text "LOS" disappears when i applied a shader onto it, problem is solved by tamte who looked at the file - Thanks to tamte.
It was due to the constant color coming from one of the two Lighting Models i had in the shader, constant color covered the text so switching it to another type such as Lambertian will fix it.
Here's the thread,
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=22591
Awesome, now i can focus on the shader!
Before
After
Rework on hammer model
At first, i was using a curve and "Extrude SOP" to model the hammer's head but felt it's probably going to be hard to make changes and knock out more variations later if i wanted to make the hammer generator digital asset.
Went for a new approach - modeling it using a long chain "PolyExtrude SOP" which i can later use these guys to reshape the hammer's head. I liked the model's shape made by curve so using it as a guide, I recreated an identical one using polyextrude.
Curve/Extrude method
"PolyExtrude SOP" method
New problem, was trying to add edge loops on the hammer's head via "EdgeDivide SOP" which was giving me results which had edges which could not be removed by messing with the settings. I could use "Subdivide SOP" to add res to it but it would add unnecessary details, and i did not want to add one loop at a time with "Polysplit SOP".
Tried a couple more solutions like cleaning up the unwanted edges with "Dissolve SOP", didn't work out so good. Sent the problem to forum instead, and hope for the best!
Tweaking cracks/cell noise in VOPSOP
Meanwhile, I moved back to molten surface where Constant Shader issue was resolved. The cracks seem too deep and cell noise's amplitude seem too high, did some tweaking and here's the new look!
Review #2 with Steven (Industrial Mentor)
Time flies, Steven had stuff going on last Thursday and now he's back. The #1 review was fairly quick, looking at our previs & reference images/videos and he gave his comments on it - we went back and did whatever amendments we wanted. Today i will be showing the progress in production stage (mainly modeling and R&D on molten surface).
Points mentioned:
- Played the latest previs_v004 to him and see if there were any problems. Basically it was approved and changes can be made during editing stage.
- Presented the hammer model, he too suggest painting the cracks with displacement maps.
- Did some embossed text research, he suggested i could consider having surface dent in/out after the hammer smashes down. He says although it's subtle change in geometry and people may not notice it, it's subtle details like these that helps sell the shot. Agreed.
He said i could set-up some sort of mask to have a portion animate to dent in/out and time it to the hammer's collision. Didn't really understand what he meant, it was nice of him to demonstrate it.
Simply create a new attribute for a group of primitives and sliding that value allows me to animate them up/down he explained.
- Was concerned about the lighting for the molten surface, was struggling with the decision of using traditional lighting, light instancing or light emission on shader level (have shader created in SHOP have actual light emission).
His take was it may not even be necessary to go that far, i could try dropping pointlights/arealights with attenuation where the hammer collides and some designated locations.
- The cracks were too rigid and straight in his opinion, should break up that pattern with another wavey noise maybe?
Houdini Tips & Tricks (Bryan's Review)
I jumped in when he reviewed Bryan's project, he shared tips & tricks on motion blur, rendering, animation graphs. Shall explain it here even though you will see it on Bryan's blog.
Rendering Motion Blur
Bryan did a test-render of his apache's rotorblades with motion blur, here are things to take note pointed by Steven. Within "Mantra ROP", we have a parm called "Xform Time Samples" - it samples the number of times it should calculate the motion blur, if set too low, the result might look very sharp/straight rather than circular shape (in this case, rotorblades).
Note: Increasing this in Mantra will apply the setting globally, best to install this rendering parm locally on only the geometry which needs it.
To do this - select the desired object, edit Rendering Parameters, search "xform" keyword and install it.
Animation Curve (Channel Editor, functions)
The curve on the rotorblade animates it in an acceleration rate (bezier() function) which in Bryan's case wasn't appropriate.
His Apaches will be flying at a constant speed so a linear() function is better, Steven also demonstrated the use of vm_matchin/out() functions which keeps the rotating speed constant before and after the timeline.
Breaking down to single elements and passes, more controls
He explains we get more control when we breakdown our scene and it's less heavy during rendering phase. And also consider adding camera shake within post instead of animating them in 3D which will help save time (e.g. you'll only need to render 1 frame of background or any static objects).
Having all these different layers/passes/elements can be confusing but keeping them in an organized folder structure will save time at post-production & rendering! Agree, the 3rd studio project back in NYP became quite a mess because we didn't do this... hehe.
end.
No comments:
Post a Comment