HM_2020 Posted September 5, 2018 Share Posted September 5, 2018 Can someone please give me an indepth explanation as to why the CPU vs GPU sims look different? I have noticed when making a fire sim, GPU gives a bit more streaky and jagged sim (better licks) than a CPU sim which tends to be a bit more billowy with more 'shrooms' or rounder shapes in general. Sadly GPU crashes on any large scale sims yet I really like the look. How can I get CPU sims to look as streaky and jagged as GPU? Any tricks to stop a GPU sim from crashing? Cheers! Quote Link to comment Share on other sites More sharing options...
evanrudefx Posted September 5, 2018 Share Posted September 5, 2018 I noticed the exact same problem. Since my sims usually will cause my GPU to run out of memory I make sure to just to look dev without open cl. For me I think its mainly shredding microsolver that drastically changes look based on open cl on/off. I think maybe I notice it a little on disturbance too. Quote Link to comment Share on other sites More sharing options...
lukeiamyourfather Posted September 5, 2018 Share Posted September 5, 2018 Have you reached out to support? This sounds like something they should know about (if they don't already). It affects how the product works in a way that Houdini users wouldn't expect. Quote Link to comment Share on other sites More sharing options...
JJ FX Posted September 5, 2018 Share Posted September 5, 2018 (edited) Thats a normal thing. Micorsolvers on openCL calucate things a bit different. I dont think you can expect the sim on CPU and openCL look exactly the same. But I noticed thats not true for all the solvers. Eg. Grain CPU and openCL looks exactly the same. Edited September 5, 2018 by JJ FX Quote Link to comment Share on other sites More sharing options...
tinyhawkus Posted September 7, 2018 Share Posted September 7, 2018 You need to set your openCL device to cpu. What I generally do, is test out quickly on the GPU, and when I submit my sim I set the following; HOUDINI_OCL_DEVICETYPE=CPU. This will give you the same results. Interesting to note also, that comparing a CPU sim, to a openCL CPU sim can be quite a bit quicker. Have a little search around the docs, to walk you through this. 2 Quote Link to comment Share on other sites More sharing options...
HM_2020 Posted September 7, 2018 Author Share Posted September 7, 2018 11 hours ago, tinyhawkus said: You need to set your openCL device to cpu. What I generally do, is test out quickly on the GPU, and when I submit my sim I set the following; HOUDINI_OCL_DEVICETYPE=CPU. This will give you the same results. Interesting to note also, that comparing a CPU sim, to a openCL CPU sim can be quite a bit quicker. Have a little search around the docs, to walk you through this. Amazing, cheers! I will take a look. Quote Link to comment Share on other sites More sharing options...
HM_2020 Posted September 7, 2018 Author Share Posted September 7, 2018 (edited) On 9/5/2018 at 5:53 PM, JJ FX said: Thats a normal thing. Micorsolvers on openCL calucate things a bit different. I dont think you can expect the sim on CPU and openCL look exactly the same. But I noticed thats not true for all the solvers. Eg. Grain CPU and openCL looks exactly the same. Cheers, but again I am asking WHY? What does it compute differently, or what are the main reasons the sims look different? I would imagine GPU would simply just use the GPU which may sim faster, etc... but why are the maths different, etc... Edited September 8, 2018 by HowardM Quote Link to comment Share on other sites More sharing options...
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