A motion-blur prop or other tool

Blind Owl

I don't know whether this would be trivially easy or next to impossible, but it would be extremely useful, especialy to those of us (for instance me) who don't have the tools or the know-how to do it in post.

Take a flying plane or helicopter, or a supercar or superbike supposedly zooming along at high speed. If the rotors/propellors/wheels are frozen in place, there's not much sense of velocity, or flight.

So I'm picturing a disc that could be placed between the (supposedly) rotating object in question and the camera, then rotated n degrees to produce the desired radial blur. Linear blur would be equally sweet, but I can't easily imagine how that might be accomplished.

sriesch

  I'm not sure if/how in Iray, but if you render in DAZ Studio using 3DL you can do motion-blur:

   In the Render Settings pane's Advanced tab, check the "Motion Blur" checkbox. In the Timeline pane, click or drag the slider to the 2nd notch to create a second frame. Move whatever you want blurred. (Note that instances don't motion blur as expected.) Click on the key icon with the '+' in it.  Move the slider back to frame 1, then render.  If it is too grainy, in the Render Settings pane > Editor tab > All, set TODO VERIFY, I THINK "Pixel Samples (X)" and "Pixel Samples (Y)" to higher values (like 16).

  Some vehicles have spinable props, so that's easy.  If they're fixed, you can hide them and add your own prop which you can rotate.  That might be somewhat harder harder as you might have to find one that matches your vehicle in design and possibly adjust the center point to rotate it correctly.  There's a free low-resolution prop in this freebie I think: http://www.sharecg.com/v/38968/related/5/3D-Model/Macchi-C205v .  And if you have a modeling application (Hexagon, etc) you may be able to use it as a hacksaw to cut off a matching prop and make a second object out of it; it will be missing some faces, but unless you are looking from behind the prop that shouldn't matter.

Serene Night

I would like a 'tire motion and 'copter blades' prop. I know this is doable- because Petipet has included some, and there is a vendor who did it with a drone- ah, here: https://www.daz3d.com/drone

Something like this, would be cool with a heliocopter blade

They look really neat when done well.

sriesch

Drone Wasp ( https://www.daz3d.com/drone-wasp , $1.99 platinum club) has a prop blur option, and you can easily hide the other parts.  It's a full-circle blur though, not partly stopped like the drone.   Also Aircraft Colo for the tail rotor ( https://www.daz3d.com/aircraft-colo ).  One could just paste the material onto a plane and save that instead of hiding parts too.

Blind Owl

I'm wedded to Iray, so motion blur is unavailable until and unless Nvidia implements it in DS. There's a Poser freebie called the 'Foberghini' over at Rendo which has blurred textures that can be applied to the mags, and that's what got me thinking about where else something like that would be useful.

The problem (it seems to me) is that no generic radial blur texture/prop/whatever will suit every wheel, propellor, or rotor you might want to use it on. A spinning mag wheel doesn't look like a spinning wire wheel or a helicopter rotor...or the rudder, come to think of it. That's why I suggested some kind of distorting lens that could be rotated to produce the desired blur effect without replacing the original textures, including any printing on the tire's sidewalls. I think that would be pretty cool.

Griffin Avid

I usually do motion blurs in POST, And I select the area I want blurred. Copy it to a new layer, blur/motion blur and place it back.

At best, maybe a shader and or scripted shader, like how you can reduce textures for an individual item using Scene Optimizer....

You'd pick the object and start the script and it would reduce the textures/blur them and the next time you load the scene, that item(s) is reloaded with the motion blurred textures. And there'd probably be settings for wheels (front/side) and rotors and jet exhaust. And you'd start off choosing an amount and direction of the morion (trail).

FeralFey

This is an interesting topic. I guess it hadn't occured to me that the motion blurred props that I had seen in the store don't quite work with iRay. Hmmm... I'll definitely keep this in mind should I build something that that would need this feature. I'll pass the word on to my other PA friends and make them aware as well.

Blind Owl

Griffin Avid said:

I usually do motion blurs in POST, And I select the area I want blurred. Copy it to a new layer, blur/motion blur and place it back.

If I had your awesome graphic skills, I'd do it in post, too. 

 

FeralFey said:

This is an interesting topic. I guess it hadn't occured to me that the motion blurred props that I had seen in the store don't quite work with iRay. Hmmm... I'll definitely keep this in mind should I build something that that would need this feature. I'll pass the word on to my other PA friends and make them aware as well.

I'm sure it would be popular! When can we expect to see it as a PC+ item? 

MarcCCTx

Could you do the motion blur by itself in 3delight and the apply it to a billboard/decal  and add it to your iRay scene?

Blind Owl

Seems highly unlikely, since the lighting would inevitably be different. Maybe someone familiar with 3Delight would know.

For rotation blur it might be possible to to render once, then rotate e.g. the wheels by a certain amount and render again, then combine the images in post. Everything except the wheels should be a pixel-perfect copy. The trouble with that is you'd need several trial runs to get the amount of blur you wanted (supposing it could even be done that way). Far easier & simpler if you could judge the effect before hitting the 'Render' button.

BeeMKay

There's actually a product for this in the shop... https://www.daz3d.com/motion-blur-for-iray

FeralFey

BeeMKay said:

There's actually a product for this in the shop... https://www.daz3d.com/motion-blur-for-iray

Oh my goodness! I have that product, and I completely forgot that I did! LOL!!!  I swear, I have more content than sense....

father1776

for a single picture, PS can handle that, but video is a totally different animal

Szark

from the Iray Dev Blog as of July last year they do have Motion Blur working so I am hoping it is a matter of time until we get it.

kaotkbliss

Here's what I would do to make a propeller blade motion blur prop in iray

take a head on screen shot of the propeller so you have a starting point

Go into a photo program and crop the screenshot down to just the propeller (you should now have a square image of just the propeller)

paint the corners pure black

Make a selection that starts at one edge of the prop blade and goes all the way over to the same edge of the next prop blade, then fill the selected area with a black to white gradient. Do the same with all blades

Then take the image and put it in the opacity map of a primitive plane that is the size of your propeller.

If it doesn't quite come out to liking you can adjust the strength of the opacity in daz studio and see if that helps

Sven Dullah

Luckily 3DL is my favorite render engine;)

Blind Owl

Grrr.