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View Full Version : whats the best way to speed up render times ?



KeithJ
10-11-2003, 07:53 AM
I am trying to work out the best way to speed up my rendering and do not know enough to work out the best way. I tend to work on a lot of very HR stuff for print, though I do want to move toward animation

Basically I need to know what makes the biggest difference.

Graphics card?
Ram?
CPU?
a combination of the above?

I am even considering building a few additional PC's and using Screamernet/stealthnet (unless there is something better) for distributed rendering.

Perhaps somebody could point me in the direction of a website or tutorial; or even a book, that will help me to work out the best way.

Oh and if anybody knows of a detailed tutorial on surfacebaking that may be of some use too.

heres hoping :)

Keith:confused:

Mylenium
10-11-2003, 08:23 AM
Well, the fastest way would be not to render at all and use wireframe only *grin*. Ok, but now seriously:

a) From the machine side, fast CPU's and enough RAM are the key to faster rendering. You can neglect graphics card power, if you do not work on the machine and only use it for rendering. IT's as simple as that.

b) On the software side, there can be no general recipe. There are too many things to consider. For instance the overall number of polygons does not necessarily affect how fast your scenes render. If they are small, do not overlap too much and have "good" angles, even millions of polys can render fast while on the other hand only a few full screen polys directly in front of the camera can slow down rendering to a crawl. In general it's a good idea to avoid features such as motion blur, volumetric effects, reflections and refractions as well as radiosity but one day you may need them and can't avoid long rendering times. I suggest you take the time and build a test scene and play around with various settings. Once you get the hang of it, it should not be too difficult to avoid overly lengthy rendering times.

Mylenium

Integrity
10-12-2003, 09:23 PM
I agree with Keith here, the faster the CPU and the more RAM the better. Just to tell you, the graphics card will not matter when rendering. The graphics card is used in OpenGL...when your making the model and scene. And as far as I know, it is also used in the calculations of Motion Designer and particle effects. But when rendering, it is all the CPU and RAM, no hardware cards are used.

There is one way though to speed some things up. There was a post here before but I can't remember it, but it was the trick where you put a fully transparent polygon in front of the camera. This forces Lightwave to render only the polygons that you will see. But I have heard when using Ray Trace Reflections and all that with this trick, it doesn't help on the rendering times.

Hope this helps.

[email protected]

Integrity
10-12-2003, 09:24 PM
Sorry about that, I meant to say Mylenium in the first sentence there, not Keith.

richpr
10-12-2003, 11:42 PM
Use network rendering... and have multiple computers work on an image/animation etc. via the Screamernet II option or with additional programs...

I use my main machine (P4-2530) and for anims I can use two additional P4-1800s, a P3-733 and old P2-300...

There are commercial and free programs for network rendering... Amleto, Lightnet, Spider, Tequila... I just use SN2 from layout...

10-13-2003, 06:58 AM
If you are raytracing reflection and or refraction, 'Ray Recursion limit' makes a very big difference.
The LW default of 16 can be very slow indeed.
For most scenes 4 is sufficient, and if it appears to produce errors - i.e. multiple refracting/reflecting (i.e. glass) surfaces go dull , you can very often simply add a suitable reflection/refraction map to the surfaces involved , which will sort of 'take over' after the 4the reflection refraction.
For this scene of a revolving crystal globe with accoutrements, the render time for this still (half res, enhanced low antialiasing) was 365sec with recursion set at 4, and I did a very quick 'background' run at half res with no antialiasing and without the globe, I used this run as both reflection map and refraction map on all the crystal surfaces. With recursion set at 16 render time soared to 945 sec but the image quality was inidiguishable fro the refmapped one.

Ryko
10-13-2003, 08:43 AM
I would recomand for videous to use low antializing and soft filter in camera properties. Video pixels become invisible enough.;)

Ryko
10-13-2003, 09:08 AM
I also would sujest to set 8 threads in render option meniu. It somehow accelerates rendering.

Hervé
10-13-2003, 09:14 AM
other way would be baking illumination....

just a pov